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Caffeine for Sports Performance is the definitive resource for all your questions regarding caffeine and its impact on sports performance. Based on the most recent research, studies, and guidelines, this guide is ideal for athletes and fitness enthusiasts looking to improve training and competition. Inside you will find these features:
• The history of how caffeine has become the most widely used drug in the world
• The pros and cons of using caffeine, including habitual daily caffeine intake, to boost sports performance
• Personal usage guides that can be applied to various sports or scenarios of caffeine use in training and competition
• Health advice regarding caffeine use
• Performance effects of caffeine use
• Safety considerations and potential risks
• Best and worst sources for caffeine
Caffeine for Sports Performance provides plenty of practical tips for using caffeine. In particular you will find sidebars that feature interviews with top athletes and coaches who have interesting stories to tell regarding their experiences using caffeine. You will also gain new insight into current attitudes towards caffeine and how those attitudes have changed over the years.
Caffeine for Sports Performance gives you all you need to understand and use caffeine to get the most out of your sport.
Chapter 1 A Brief History
Chapter 2 What Is Caffeine and What Does It Do?
Chapter 3 Where Is It Found?
Chapter 4 How Is It Used?
Chapter 5 Does It Work?
Chapter 6 Is It Safe?
Chapter 7 Should It Be Legal?
Chapter 8 Recovery and Other Considerations
Chapter 9 Will It Work for You?
Chapter 10 Putting It All Together
Professor Louise Burke is a sports dietician with nearly 30 years of experience in the counselling and education of elite athletes. Since 1990 she has served as the head of sports nutrition at the Australian Institute of Sport and served as the team dietician for the Australian Olympic team for five Summer Olympics from 1996-2012. Burke is also director of the International Olympic Committee diploma in sports nutrition and is part of the Nutrition Working Group of the IOC. Her research and education interests in sports supplements have included work on caffeine and sports performance. Louise has a very modest caffeine habit. She hates coffee and has never tried an energy drink, and her daily caffeine intake consists (to her husband’s annoyance) of half-cups of weak black tea. She is committed to practicing her (also very modest) sporting ability. Towards the end of her annual marathon she consumes caffeinated cola drinks or sports confectionary, which gets her to the finish line with a smile on her face.
Dr. Ben Desbrow is a sports dietician and senior lecturer at Griffith University in Queensland, Australia. He completed his PhD in 2008 investigating the effects of cola beverages on endurance exercise performance. In 1999, Desbrow was awarded the first Nestlé Fellowship in Sports Nutrition at the Australian Institute of Sport. Since that time he has worked with many sporting groups, including the 2000 British Olympic team and the Australian Institute of Sport Cricket Centre of Excellence. Desbrow has co-authored numerous articles on caffeine use by both athletes and the general population for scientific nutrition journals. Desbrow is currently conducting new studies investigating caffeine’s ability to influence exercise performance. Ben has an addiction to iced coffee, which usually manifests as confusion around lunch time on most workdays. The solution can only be found by consuming 1 of 3 particular brands (he has a refined palate) or by his own homemade (secret) version. He completed his PhD investigating the effects of cola beverages on endurance performance--an achievement fuelled entirely by caffeine.
Dr. Lawrence L. Spriet is a professor in the department of human health and nutritional sciences at the University of Guelph in Guelph, Ontario, Canada. Dr Spriet received his bachelor's degree in kinesiology at the University of Waterloo, his master's degree in exercise physiology from York University in Toronto, and his doctoral degree in medical sciences from McMaster University. He was a post-doctoral fellow at Huddinge Hospital, Karolinska Institute in Stockholm, Sweden, and a visiting scientist in the School of Health Sciences, Deakin University, Melbourne, Australia. He has studied the regulation of fat and carbohydrate metabolism in skeletal muscle metabolism during exercise and has also worked on the effect of various nutritional and pharmacological interventions on athletic performance. His research output appears in numerous scientific journals, including Journal of Physiology, American Journal of Physiology, and Journal of Applied Physiology. Dr. Spriet is a member of the editorial board for the International Journal of Sports Medicine and the U.S.-based Sports Medicine Review Board of the Gatorade Sports Science Institute. He is also the chair of the Canadian Gatorade Sports Science Institute. Lawrence is a committed caffeine user. He first sampled the benefits of cofffee use while completing his MSc degree many years ago. Coffee now starts his every day, except when he's volunteering for a caffeine withdrawal study! Two to three additional cups of coffee punctuate the day, and just having the cup on the desk is a positive influence on the many tasks that need to be done.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Cola drink study shows caffeine improved time-trial performance in cyclists
In the late 1990s, our excitable colleague, Dr. Dave Martin, returned from a professional cycling race with an improbable story.
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/65se_Main.png
http://www.humankinetics.com/AcuCustom/Sitename/DAM/097/66se_Main.png
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Dangers exist with the excessive consumption of energy drinks due to their caffeine content, and alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people.
Mixing Energy Drinks and Alcohol
Athletes normally are very disciplined people who carefully plan most aspects of what they do. But they also need downtime and like to party as much as (and sometimes more than) other people. The relationship between alcohol and caffeine used to be the search for a strong coffee brew as a pick-me-up after a late night of drinking or as an aid to sobering up. Now, however, it is common, especially among young people in party situations, to consume caffeine-containing products while they are consuming alcohol. In some countries, the combination of alcohol and caffeine exists in commercial products. However, the more typical scenario involves the self-mixing of energy drinks with alcoholic beverages such as spirits. The idea is that the uplifting and arousing effects of the energy drink counteract the depressant effects of alcohol, although in some cases people use the energy drinks to disguise the taste of the alcohol. Decreasing the subjective perceptions of being intoxicated may deliberately or inadvertently allow drinkers to increase their alcohol consumption.
The numerous constituents in energy drinks, such as taurine, ginseng, amino acids, inositol, ribose, and choline, have generally failed to show any active effects. This leaves the ingredients of interest in energy drinks as carbohydrate and caffeine. On the surface it may look as though an energy drink is optimal for energizing the muscles and the brain with its high carbohydrate content (9-15 g per 100 ml) and caffeine boost of 50 to 120 mg per serving. However, although the amount of caffeine added to many energy drinks is low to moderate and stated on the label, the total caffeine content of some drinks may not be specified due to the inclusion of other caffeine-containing compounds such as guarana, yerba maté, and kola nuts. The real concern comes when energy drinks are consumed in large volumes, which can easily happen if the athlete is determined to have a big session with alcohol and uses energy drinks as a mixer or chaser. There is already much concern regarding the dangers of excessive consumption of energy drinks due to their caffeine content, but the interaction with alcohol adds another dimension.
The literature is full of reports documenting the use of energy drinks along with alcohol. For example, studies from various countries have reported that 54% (United States), 25% to 40% (France), and 40% (Turkey) of college students consumed energy drinks with alcohol while partying, with many users reporting that they consumed at least three servings during the partying episodes (United States). The worry is that this type of behavior leads to a greater predisposition to alcohol dependence. However, a recent study from the Netherlands argues that a personality trait with higher levels of risk-taking behavior may be the primary reason for increased alcohol and drug abuse and that the co-consumption of energy drinks with alcohol is simply an expression of that type of lifestyle and personality. However, given the high prevalence of the co-consumption in young people, this explanation seems unlikely to account for the majority of people exhibiting this behavior.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Is caffeine a threat to hydration or rehydration?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight.
Is Caffeine Really a Diuretic?
We all know that caffeine is a diuretic. A cup of coffee makes us dash to the restroom and for every cup we drink, we need to add another glass of water to our daily eight. That can't be good for athletes who are already losing buckets of sweat during exercise, right? Or for the plane flight home after the race? After all, the airline magazine on your flight home carries a warning along the lines of “drink tea and coffee in moderation since these are diuretics and will increase your dehydration,” so it must be serious. Drinking caffeinated drinks before and during exercise on a hot day is particularly risky because your performance will go down the toilet. The threat to hydration or rehydration probably rates as one of the best known facts about caffeine.
Except that it's not true. Several experts have recently tried to debunk this old wives' tale about caffeine and dehydration. We like the work of Professor Lawrence Armstrong because it takes into account issues related to exercise. Here are some of his observations from 2002 and 2005.
- A diuretic is a substance that increases the production of urine. By definition, water or any drink consumed in large volumes is a diuretic. The effect of any fluid on body hydration is judged by the balance sheet of how much the body retains of any volume that is consumed.
- Caffeine is a weak diuretic. It may influence the volume of urine production and loss by acting on some of the hormones involved in urine production, and it may also influence the loss of electrolytes in urine. However, tolerance to the diuretic effects of caffeine is acquired in as little as 4 or 5 days of regular caffeine intake. Studies in the 1920s showed that for someone who hadn't consumed caffeine in more than 60 days, a dose as little as 0.5 g/kg (e.g., 35 mg for a 70 kg person) caused a noticeable increase in urine losses. However, regular caffeine intake created a tolerance to the diuretic effect such that a dose of 1.12 g/kg was needed before an effect on urine losses was detectable.
- A variety of studies have compared urine losses when subjects consumed caffeine with or as part of a beverage compared with water or a noncaffeinated control or placebo condition. Most were undertaken in sedentary conditions, and a couple were undertaken after exercise or during exercise. Caffeine doses ranged from low (~100 mg) to high (~700 mg) and urine losses were tracked for several hours (up to 24 hours). In some cases, the differences in urine losses between caffeine and no caffeine were judged to be similar; in others, the urine losses in the caffeine trial were significantly greater according to a statistical interpretation. Small to moderate intakes of caffeine (
- When healthy people were followed over 11 days in which their caffeine intake was first stabilized for 6 days and then manipulated for 5 days at zero, low (3 mg/kg), or moderate (6 mg/kg) levels, there was no significant effect on urine production or characteristics.
Armstrong concluded that the consumption of caffeine doesn't pose a threat to hydration levels via its alleged diuretic actions, particularly in small to moderate doses, and that any effects on urine losses are small and unimportant. A systematic review by Professor Ron Maughan, who we introduced in the preface of this book, came to a similar conclusion (Maughan and Griffin 2003). The summary to this publication stated that the available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg) . . . results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action. . . . The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine-containing drinks in situations where fluid balance might be compromised.
Before leaving the issue of caffeine and hydration, we should examine two specific variations on this theme. Urine losses contribute to fluid balance, of course, but the big picture is far more complicated than that. The minus side of fluid balance also includes sweat losses, and it has been proposed that caffeine intake might increase sweat rates either by directly affecting the sweat glands or by raising metabolic rate and body temperature. This might be of greatest importance to consider when an athlete is exercising in hot weather, and caffeine use might have an effect on heat regulation as well as hydration. Several studies have examined this issue, and in addition to measuring the individual components of fluid balance, they have looked at the bottom line of total fluid balance, body temperature regulation, and performance. The findings have been consistent: Caffeine intake before and during exercise has zero to minor effect on sweat losses, body temperature, and urine losses during exercise. However, there is no detriment to total hydration, temperature control, or performance compared with trials without caffeine. Therefore, decisions to use moderate doses of caffeine before and during exercise in hot conditions need not be overly concerned about heat and hydration.
The final issue that we need to address regarding caffeine and hydration is the plus side of the fluid balance sheet. A key consideration in real life is that a drink needs to be consumed before it contributes to body fluid levels. As much as thirst is important, people also drink according to habit, social behavior, fluid availability and personal preferences. Caffeine-containing drinks score highly in each of these areas. Beverages such as tea, coffee, cola drinks, and in some populations, energy drinks, contribute a significant volume of our daily voluntary intake of fluid. In some cases, there may be good reasons to suggest we should reduce our total or specific intake of these drinks. We now know that fluid balance isn't likely to be one of these reasons, although we know of people who swear that they have to get up in the night to go to the bathroom if they drink caffeine-containing drinks before bed. But, we also need to recognize the value of the fluid that they do contribute to our daily balance. If people were to suddenly give up their normal intake of caffeinated beverages, the net effect might be a reduction in fluid intake until they found other drinks that were similarly enjoyable, ubiquitous, and easy to ingrain into their habits and social routines. The Perfect Study sidebar illustrates a case in point.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
Caffeinated drinks date back to the 1400s
Around the world, coffee and tea have become the major sources of caffeine intake.
A Brief History of Caffeinated Drinks
Around the world, coffee and tea have become the major sources of caffeine intake. The preparation of coffee from roasted coffee beans apparently started in the Middle East in the 1400s before spreading to Europe around 1600 and then the Americas in the 1700s. The brewing of tea from tea leaves can be traced back to various Chinese dynasties from several centuries BC. However, globalization required the efforts of Marco Polo (1200s) and the Dutch East India Company (1600s), with tea drinking gaining popularity in Europe in the late 1600s and coffeehouses becoming fashionable from the 1600s onward. Although these establishments were primarily centers of social interaction, coffee and particularly tea were noted as tonics and used to treat a variety of ailments.
The evolution of the world's third most popular caffeine source, cola drinks, is an interesting tale involving both health and sport. Mineral waters from natural springs had been popular as both baths and beverages for centuries because of beliefs about their health-promoting properties. The late 1700s was the era of campaigns to produce a human-made version of these tonics. The first such glass of carbonated water was created by an English scientist, Dr. Joseph Priestley, who was also credited with the discovery of oxygen and carbon monoxide. Other scientists also found ways to achieve this feat, but their outcomes were always on a small scale.
It took the combination of a jeweler named Johann Jacob Schweppe, an engineer, and a scientist to perfect the process of making artificial mineral waters on a large scale, with Schweppe moving the successful business to England. Patents were established there and in the United States for “means to mass manufacture imitation mineral waters.” One of these means was the soda fountain, and because mineral waters originated as a health tonic, the neighborhood pharmacy became the popular place to dispense sodas. Throughout the late 1800s, American pharmacists started to add medicinal or flavor-providing herbs to the unflavored drinks. This led to cola drinks, followed by the development of soda-producing companies with trademarked names and beverages, particularly Coca-Cola and Pepsi-Cola. Table 1.1 summarizes the origins of the two cola giants along with their original ingredients and health claims. When launched, Coca-Cola's two key ingredients were cocaine from the cocaleaf and caffeine from the kolanut, explaining its name. Shortly after the turn of the century, it moved to using “spent” coca leaves from which the cocaine had been extracted, leaving caffeine as the only stimulant. The rest, as they say, is history.
The original marketing of cola beverages focused solely on their claimed medicinal properties. Soon, however, companies realized that people enjoyed consuming these drinks, and to increase sales, they wanted to remove the stigma associated with taking medicine. The focus of advertisements moved away from the concept of medicinal elixir and more toward life enhancer. Additionally, promotion and sponsorship became the tools to market expansion. This included aligning products with sport celebrities and other high-profile members of society.
In 1909, automobile racing pioneer Barney Oldfield became the first Pepsi celebrity endorser when he appeared in newspaper advertisements describing Pepsi-Cola as “A bully drink . . . refreshing, invigorating, a fine bracer for a race” (www.pepsiusa.com/faqs.php?section=highlights). In 1928, 1,000 cases of Coke traveled with the U.S. Olympic team to the Amsterdam Olympics. Coca-Cola has continued its association with the Olympic Games to this day: It is the longest continuous corporate partner, and it is a member of The Olympic Partner (TOP) program, the top-level sponsorship awarded to a handful of sponsors with exclusive worldwide marketing rights to the Winter and Summer Olympic Games. Around the world, PepsiCo and Coca-Cola continue to sponsor a large range of regional and international sporting events and teams, seeing sport sponsorship as a natural fit.
Read more from Caffeine for Sports Performance by Louise Burke, Ben Desbrow, and Lawrence Spriet.
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