Hangout no.5: Nutrición Deportiva - Tabla cafeína


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Hangout no.5: Nutrición Deportiva - Tabla cafeína

  1. 1. AIS WEBSITE FACT SHEET – AIS SPORTS SUPPLEMENT PROGRAM Caffeine Supplement Overview Caffeine (1,3,7-trimethylxanthine), is a substance found naturally in the leaves, beans and fruits of a variety of plants, and is regularly consumed by ~ 90% of adults. The most common dietary source of caffeine is coffee, but cola drinks, energy drinks and specialised sports foods and supplements also contribute to regular intake. We lack accurate information on the typical daily caffeine intakes of Australians; however, it is likely to be around 250-300 mg (3-5 mg/kg body mass). Caffeine intake has been linked with a number of health issues; however whether caffeine contributes to an increased or decreased risk of various diseases is unclear. Various health agencies from countries around the world consider caffeine to be a generally safe compound especially when it is consumed in low to moderate levels. These levels are defined as Low: 80-250 mg/d (1.1-3.5 mg/kg BM) Moderate: 300-400 mg/d (4-6 mg/kg BM/d) The use of caffeine by children carries greater risk, and children < 12 y are suggested to limit caffeine intake to < 2.5 mg/kg/d. On 1 January 2004, caffeine was removed from the 2004 World Anti-Doping Agency Prohibited List, allowing athletes who compete in sports compliant with the WADA code to consume caffeine within their usual diets or for specific purposes of performance. This change was based on the recognition that caffeine enhances performance at doses that are indistinguishable from everyday caffeine use, and that the previous practice of monitoring caffeine use via urinary caffeine concentrations is not reliable. WADA continues to test urinary caffeine concentrations within its Monitoring program to investigate patterns of misuse of substances in sport. This Monitoring Program has not revealed systematic changes of use or abuse of caffeine in sport since the 2004 status change. Caffeine is rapidly absorbed and transported to all body tissues and organs where it exerts a large variety of effects. The mechanisms underpinning these effects may vary between individuals and include both positive and negative responses. Effects include the mobilisation of fats from adipose tissue and the muscle cell, changes to muscle contractility, alterations to the central nervous system to change perceptions of effort or fatigue, stimulation of the release and activity of adrenaline, and effects on cardiac muscle. Some popular beliefs about caffeine have been refuted by recent research: 1. Caffeine enhances endurance performance because it promotes an increase in the utilisation of fat as an exercise fuel and 'spares' the use of the limited muscle stores of glycogen. In fact, studies now show that the effect of caffeine on 'glycogen sparing' during sub-maximal exercise is short-lived and inconsistent - not all athletes respond in this way. Therefore, it is unlikely to explain the enhancement of exercise capacity and performance seen in prolonged continuous events and exercise protocols. 2. Caffeine-containing drinks have a diuretic effect and cause an athlete to become dehydrated. In fact, small to moderate doses of caffeine have minor effects on urine losses or the overall hydration in people who are habitual caffeine users. In addition, caffeine-containing drinks
  2. 2. such as tea, coffee and cola drinks provide a significant source of fluid in the everyday diets of many people. Evidence of the use of caffeine to enhance sports performance is at least a century old and a robust body of research on caffeine and exercise has developed over the last 40 years. New insights which have evolved over the past decade include the following: Caffeine intake enhances the performance of a wide variety of sports (see situations for use in sport). A variety of protocols of caffeine intake, including consumption before and during exercise, can enhance performance. Furthermore, caffeine doses as low as 2-3 mg/kg are effective. Thus, the “standard” protocol of caffeine use - a dose of 6 mg/kg body mass (BM) taken an hour prior to exercise - needs to be updated (see products and protocols). The major benefits of caffeine on exercise capacity and performance appear to be achieved by central nervous system effects. These effects reduce the perception of fatigue and allow optimal pacing and skill/work outcomes to be maintained for a longer period. Individuals vary in their response to caffeine intake. Although caffeine may enhance sports performance in most people, some people are non-responders and others may respond negatively. Products and protocols A range of products provide caffeine in our everyday diets. Table 1 provides a summary of common foods, drinks and over-the-counter preparations available in Australia, while Table 2 provides a summary of products that are more specifically targeted to athletes. Several issues are noted: The manufacture of caffeine containing products in Australia is regulated variously by Food Standards Australia New Zealand (“FSANZ”) or the Therapeutic Goods Administration. Foods, which naturally contain caffeine and have a long history of use and consumer awareness/association with caffeine, such as tea, coffee and cocoa, are exempt from labelling requirements and the addition of these caffeine sources to other foods is allowed. Although values for the “typical” or “average” caffeine content of different types of coffee beverages can be gained from food tables, there is a considerable range in the actual caffeine content of these beverages. This is the case even when standard preparations are compared; for example, the same preparation from commercial coffee outlets, including the same franchise or the same outlet on different days. Therefore, it is difficult to predict or guarantee a desired dose of caffeine using coffee as a source. Coffee can potentially provide a substantial dose of caffeine in a single serve. Studies of beverages purchased from commercial outlets have documented caffeine doses of >200 mg in a small volume caffeine beverage and >500 mg in a large volume beverage from specialty coffee franchises. Iced coffee and cold caffeinated drinks (i.e. frappes) can also contain a substantial dose of caffeine with a commercially available single serve providing up to 200 mg of caffeine. Cola drinks, energy drinks, sports foods and therapeutic goods represent an additional source of caffeine in the food supply and are a popular choice among specific population groups (e.g. adolescents and young adults). While cola drinks have been available for over a century, “energy” drinks are a more recent and increasingly popular caffeine source. The Australian
  3. 3. Foods Standards Code allow for the addition of caffeine to cola drinks at a maximum level of 145 mg/L while energy drinks, known in the code as Formulated Caffeinated Beverages, can contain caffeine from all sources (caffeine and guarana) of up to 320 mg/L. Energy drinks must state their caffeine content on product labels. The Australian Food Standards Code provides greater regulation of caffeine-added products than found in other countries. It restricts the development of new food products containing non- traditional sources of caffeine (including guarana) beyond the current provisions. In May 2011, FSANZ announced a further review of the Policy Guidelines on the addition of caffeine to foods. *Denotes range of values from studies in which standard serves of the same beverage were analysed # cola and energy drinks are available in a range of individual serve sizes ranging from 150 ml-750 ml. Table 1: Caffeine content of common foods, drinks and therapeutic products (Australia) adapted from Burke et al. 2012 from a variety of sources Food or Drink Serve# Caffeine Content (mg) Instant coffee 250 ml cup 60 (12-169)* Brewed coffee 250 ml cup 80 (40-110)* Brewed coffee (same outlet on different days) 250 ml cup 130-282* Short black coffee/espresso from variety of outlets 1 standard serve 107 (25-214)* Starbucks Breakfast Blend brewed coffee 600 ml (Venti size) 415 (300-564*) Iced coffee - Commercial Brands 500 ml bottle 30-200 depending on brand Frappuccino 375 ml cup 90 Tea 250 ml cup 27 (9-51)* Black tea 250 ml cup 25-110 Green tea 250 ml cup 30-50 Iced Tea 600 ml bottle 20-40 Hot chocolate 250 ml cup 5-10 Chocolate – milk 60 g 5-15 Chocolate – dark 60 g 10-50 Viking chocolate bar 60 g 58 Coca Cola# 375 ml can/600 ml bottle 36/58 Diet Coke 375 ml can/600 ml bottle 48/77 Pepsi 375 ml can/600 ml bottle 40/64 Red Bull energy drink# 250 ml /330 ml/500 ml can 80/106/160 V Energy drink 250 ml/350 ml/500 ml 78/109/155 Mother energy drink 150/300 ml/500 ml can 48/96/160 Monster energy drink 340 ml/500 ml can 109/160 Lipovitan energy drink 250 ml can 50 Rockstar 500 ml can 160 Vitamin water – energy 500 ml bottle 82 No Doz (Australia) 1 tablet 100
  4. 4. Some carbohydrate-containing sports foods, such as sports drinks, gels and bars contain small amounts of caffeine – typically, 20-80 mg per serve (see Table 2). Two other supplement categories also typically contain a source of caffeine: Fat loss products and Pre- workout/”activation” supplements. Table 2 provides examples of products available in Australia, which fall under the jurisdiction of Therapeutic Goods Administration. Concerns regarding these supplement categories include the lack of information on the caffeine dose provided by a typical serve of these products and the potential for large caffeine doses. Table 2: Caffeine content of common sports foods and supplements (Australia) Adapted from Burke et al. 2012 from a variety of sources Product Serve Caffeine content (mg) Sports food Powerade Fuel+ sports drink 300 ml can 96 PowerBar caffeinated sports gel 40 g sachet 25 PowerBar double caffeinated sports gel 40 g sachet 50 PowerBar caffeinated gel blasts 60 g pouch (~9 lollies) 75 Gu caffeinated sports gel 32 g sachet 20-40 Carboshotz caffeinated sports gel 50 g sachet 80 PB speed sports gels 35 g sachet 40 PowerBar Performance bar with Acticaf 65 g bar 50 Pre-workout supplements Musashi Re-activate Hard core 15 g powder serve 120 Body Science (BSc) K-OS 13 g powder 150 Jack 3D 5 g powder ? [ingredients: “caffeine”] No-Xplode 18 g ? [ingredients: “methyl xanthine (caffeine)”] Assault 20 g ? [ingredients: “caffeine”] 1 MR 8 g 300 No-Shotgun 22 g ? [ingredients: “caffeine”] Amped NOS 40 g ? [ingredients: “caffeine”] Animal Rage 1 stick ? (ingredients note caffeine/coffee bean extract) Code Red 10 g powder ? [ingredients: “caffeine”] Fat loss supplements Oxyelite pro 1 capsule 100 Body Science (BSc) Hydroxyburn Pro 40 g ? (24 mg guarana listed on label) Body Science (BSc) Hydroxyburn Hardcore 3 capsules 210 (70 mg per capsule) Muscle Tech Hydroxycut Hardcore pro 40 g sachet ? [ingredients: “caffeine”] Shred Matrix 1 capsule ? [ingredients: “caffeine, guarana, yerba mate”] Animal Cuts 10 g ? [ingredients: “caffeine”]
  5. 5. Table 3 shows examples of manufactured food/supplement products from the USA which illustrate several differences in caffeine regulations between countries. A greater range of caffeine-added products is available than in Australia and larger doses of caffeine are available in smaller volumes or single serve portions of various items. (Note that some products with greater amounts of caffeine/serve than permitted by FSANZ regulations – e.g. caffeine “shots” – may be available for purchase in Australia. This is usually due to a breach of customs laws or an attempt to exploit the so-called Trans Tasman Mutual Recognition Act which allows products manufactured and sold in New Zealand to be imported to Australia). A specific issue of current concern in the US is the manufacture of alcoholic drinks containing usually unstated amounts of caffeine (e.g. “Four”, “Joose”). The consumption of large amounts of caffeine in association with alcohol is of concern. These products have recently been challenged by the US regulator (Food and Drug Administration; FDA), leading to pledges by manufacturers to reformulate their products to remove the caffeine. The traditional protocol of caffeine use in sport and sports science research has been: A caffeine dose equivalent to 6 mg/kg body mass, consumed 60 min prior to the start exercise. Typically, a period of caffeine withdrawal prior to the competition or study trial to heighten the effect of caffeine. Caffeine withdrawal can be achieved by 24-48 hour of absence of caffeine consumption. Over the last decade, however, it has become clear that this traditional protocol is not best practice and needs to be updated: A large number of studies now show that caffeine intake can enhance performance at significantly lower doses of intake – i.e. 1-3 mg/kg. If there is a dose–response relationship between caffeine intake and exercise performance (i.e. the bigger the dose, the better the performance outcome), the plateau seems to occur at a dose of ~ 3 mg/kg. This offers athletes the opportunity to consume caffeine for performance benefits at doses that are less likely to Table 3: Caffeine content of other sources available in USA. Adapted from Burke et al. 2012 from a variety of sources Food or Drink Serve Caffeine Content (mg) AMP Energy 500 ml can 143 Spike Shotgun energy drink 500 ml can 350 Fixx Extreme Ultra shot 5 ml shot 400 Ammo energy shot 30 g shot 170 Jolt endurance shot 60 g shot 200 Extreme Sports beans – caffeine 28 g packet 50 Jolt caffeinated gum 1 stick 40 Stay Alert gum 1 stick 100 Excedrin Extra strength 1 tablet 65 No Doz (Maximum strength) 1 tablet 200
  6. 6. cause side effects, well within normal population caffeine use patterns, and from the caffeine doses provided by a range of well accepted foods and sports foods Studies and anecdotal observations now show that benefits from caffeine occur soon after intake and are not reliant on the achievement of peak blood caffeine concentrations. These sources also show that there are a variety of protocols of caffeine intake that can enhance performance. These include the consumption of caffeine before the exercise bout, spread throughout exercise, or late in exercise as fatigue is beginning to occur. Different protocols may achieve optimal performance outcomes even in the same sport or individual. Suitable or optimal protocols may be dictated by the specific characteristics of the event, the practical considerations of consuming a caffeine-containing product, and the individual characteristics/preferences of the athlete. The athlete who is intending to use caffeine to enhance sports performance should experiment in training or less important events to determine the protocol(s) which best suit their individual needs. There is doubt about the value of withdrawing from caffeine use prior to using it for competition to “heighten” the subsequent effect on performance. Observations of a greater performance improvement following a period of caffeine abstinence may be an artefact – caffeine withdrawal may impair general well-being and performance and the apparent increase in benefits when caffeine is reintroduce is partly explained by the reversal of these negative effects. Well- designed studies show that there is no difference in the performance response to caffeine between non-users and users of caffeine, and that withdrawing athletes from caffeine does not increase the net improvement in performance achieved with caffeine supplementation In summary, athletes do not need to consume large doses of caffeine, or to consume more caffeine than the rest of the population, to achieve their sporting goals. Athletes who want to use caffeine to enhance sports performance should develop supplementation protocols that use the lowest effective caffeine dose. Situations for Use in Sport Most studies of caffeine and performance have been undertaken in laboratories. Studies that investigate performance effects in elite athletes under field conditions or during real-life sports events are scarce and need to be undertaken before specific recommendations for caffeine supplementation protocols can be made. Nevertheless, there is sound evidence that caffeine may enhance the performance of a range of sports: Endurance sports (> 60 min) Brief sustained high-intensity sports (1-60 min) Team and intermittent sports – work rates Team and intermittent sports – skills and concentration The effect of caffeine on the following aspects of sports is unclear, mostly due to a lack of available research Skill sports involving low intensity exercise Single efforts involving strength or power (effects appear to be small and limited to certain muscle groups) Chronic effect of using caffeine to enhance training performance
  7. 7. Concerns Associated with Supplement Use The effects of caffeine vary markedly between individuals. Each athlete should make decisions about caffeine use, both socially and for sports performance, based on experience of their own responsiveness and reactions, including side-effects. There is evidence that some athletes do not follow best practice for caffeine use in training, for competition performance or in their everyday (“social”) intake of caffeine. The current caffeine use for training sessions and competition by some athletes is ad hoc and unsystematic. At best, these practices are ineffective but in the worst case scenario, they may be detrimental to health and performance. Some athletes take unnecessarily high doses of caffeine for performance enhancement and appear to lack awareness of the potential for side-effects or negative outcomes from such use. The culture of sports, including the “more is better” principle might contribute to poor caffeine supplementation practices and caffeine misuse. Some athletes and coaches lack awareness of the new insights into caffeine and sports performance. The effects of the acute intake of caffeine follow a U-shaped curve. Although low-moderate doses produce positive effects and a sense of well-being, the effects of higher doses of caffeine can be negative. At higher levels of intake, caffeine can cause increases in heart rate, impairments or alterations of fine motor control and technique, and anxiety or over-arousal. This may have health consequences as well as interfering with sports performance. Caffeine can affect sleep latency and quality, even at low levels of intake. This may interfere with the athlete’s ability to recover between training sessions, or multi-day competitions. We are aware of poor caffeine practices, particularly involving evening sports events, which lead to a cycle of use of pharmaceutical aids to induce sleep, followed by caffeine to restore wakefulness and alertness next day, and further caffeine use for subsequent performances. There may be interactions between caffeine and other supplements/nutrients used by athletes (e.g. bicarbonate, creatine, nitrate/beetroot juice) that need to be explored in terms of performance outcomes and potential side-effects. Although evidence of specific health problems is equivocal, long-term intake of large amounts of caffeine (>500 mg per day) are generally discouraged by health authorities. Athletes should be aware of the side-effects of withdrawal such as headaches and lethargy. Community members are rightly concerned about caffeine misuse in sport; however, the public perceptions of caffeine use by athletes are often misinformed and underpinned by emotive rather than factual views. Public perceptions include the belief that some sources of caffeine (e.g. therapeutic goods such as caffeine tablets) are inherently worse than others (e.g. coffee), even though the caffeine dose may be smaller and able to be planned. Other beliefs are that caffeine use for sports performance contravenes the ethics of sport, or that caffeine achieves a stimulatory effect that gives athletes a super-human advantage. In fact, the “spirit of sport” is one of the three factors that are considered by WADA in its deliberations to remove caffeine from the Prohibited List. Furthermore, the new research on caffeine and sports performance shows that caffeine exerts its major effect by reducing the actual or perceived fatigue which occurs when an activity is undertaken for a prolonged period. This is similar to the benefit that underpins the everyday use of caffeine by community members: caffeine enhances well-being and alertness and increases the time that an individual can sustain their optimal output or pace while undertaking occupational or recreational activities.
  8. 8. Some sports science/medicine practitioners who work with elite athletes or provide commentary to the media on such matters are not up to date with the contemporary information on caffeine or its use to enhance sports performance. They may contribute both to the reality and perception of caffeine misuse in sport. Policy on Caffeine Use at the AIS The WADA stance on caffeine in sport clearly states that caffeine use by athletes is not banned. Questions and Answers on the WADA 2012 Prohibited List The AIS has a role in providing educational resources for elite athletes to allow them to stay up to date with the latest information on caffeine and sports performance, and therefore be able to make sensible and well considered decisions about their caffeine use. AIS Sports Nutrition will work with AIS athletes who have decided to use caffeine in training or competition scenarios to develop protocols that involve the smallest effective dose of caffeine. AIS activities with caffeine will involve medical supervision, research programs undertaken with the approval of its Independent Ethics Committee, and a central register of use of caffeine-containing supplements such as caffeinated sports drinks/bars/gels/gums/confectionery. The AIS does not provide caffeine tablets within its Sports Supplement Program. Further reading Please refer to summary table on research conducted on caffeine supplementation and sports performance Last updated January 2012 . What is the status of caffeine? The status of caffeine has not changed from last year. Caffeine was removed from the Prohibited List in 2004. Its use in sport is not prohibited. Many experts believe that caffeine is ubiquitous in beverages and food and that reducing the threshold might therefore create the risk of sanctioning athletes for social or diet consumption of caffeine. In addition, caffeine is metabolized at very different rates in individuals. Caffeine is part of WADA's Monitoring Program. This program includes substances which are not prohibited in sport, but which WADA monitors in order to detect patterns of misuse in sport. The 2010 and 2011 Monitoring Programs did not reveal global specific patterns of misuse of caffeine in sport, though a significant increase in consumption in the athletic population is observed. ( This Fact Sheet was prepared by AIS Sports Nutrition as part of the AIS Sports Supplement Program ( Note that a Fact Sheet with additional information on this topic is available for Members of the AIS Sports Supplement Program at this site. The AIS Sports Supplement Program has been designed for the specific needs of AIS athletes and all attempts are made to stay abreast of scientific knowledge and of WADA issues related to anti-doping. It is recommended that other athletes and groups should seek independent advice before using any supplement, and that all athletes consult the WADA List of Prohibited Substances and Methods before making decisions about the use of supplement products. © Australian Sports Commission 2012