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If there’s one thing I know about endurance athletes, it’s that we love caffeine. After all, the very nature of our sport requires us to wake up early to jump in a frosty pool, pedal on an exercise bike, or run with a headlamp before the rest of the world gets going. Many of us consider caffeine to be part of our internal regulation, keeping us elated, alert, and firing on all cylinders. It’s the most widely consumed stimulant in the world, found in things like coffee, tea, energy drinks, chocolate, and soda. But could this constant, daily exposure to caffeine be harmful on race day?
Many of us know the benefits of caffeine as an ergogenic (work-boosting) agent that relieves feeling tired and helping to maintain intensity for longer periods of timeHowever, if you regularly drink caffeine in your daily life, you have probably been warned that your tolerance reduces its stimulation on race day. study by Carvalho et al. The aim of the study was to determine whether habitual caffeine consumption influences the overall potential benefits of caffeine consumption in both trained and untrained men and women participating in different types of sports (endurance, strength and power).
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How Caffeine Works During Exercise
Caffeine is an effective stimulant because it has a similar structure to the fatigue-inducing compound adenosine. This similar structure makes caffeine an adenosine antagonist—in other words, caffeine blocks adenosine from connecting with synapses in the brain that signal sleepiness. At the same time, there’s an indirect effect on the release of other “feel-good” neurotransmitters, including norepinephrine, dopamine, serotonin, glutamate, and possibly neuropeptides. Because the brain hasn’t gotten the message to feel tired but has gotten the message to feel energized, people feel more refreshed and alert than they did before their Starbucks run.
During exercise, caffeine was supported by moderate to high quality evidence have acute benefits such as positive effects on muscle endurance, muscle strength and aerobic endurance. However, some research suggest that massive caffeine users counteract some of the positive exercise benefits that come with caffeine apply over time. The latest study set out to determine whether this is the case by quantifying the amount of research published on massive caffeine consumption.
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Does daily caffeine consumption reduce its effectiveness on race day?
Intervention studies had to include acute caffeine supplements (any type) before the exercise task compared to a control group without caffeine supplementation during the same exercise. Finally, the exercise task results had to be assessed as changes in exercise performance or capacity. After screening, 60 caffeine studies met these requirements and were included in the meta-analysis, which included 1,137 participants—84% were male, 718 were trained, and 400 were untrained.
After statistical analysis, the results suggest a tiny positive overall effect of caffeine supplementation on endurance, power, and strength exercise performance regardless of regular caffeine intake, gender, or training level (trained vs. untrained). Furthermore, this positive effect occurred only when the acute dose was below 6 mg/kg body weight, but not above that amount. This is consistent with previous literature suggesting that amounts of 2-6 mg/kg body weight are adequate to induce an ergogenic effect on performance in Very athletes.
Furthermore, caffeine had this positive production effect regardless of whether the acute dose in the study was higher or lower than the regular daily dose of caffeine given to participants or whether the study protocol included a withdrawal period before study entry. One limitation of these findings was that only 24% (60/246 studies) reported the average habitual caffeine intake of participants, which reduced the impact of these results. Therefore, many studies did not take this into account and could not be used in the final analysis.
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Do I need to limit my caffeine intake before race day?
While many coaches suggest a period of caffeine withdrawal prior to a major race or endurance event, the results of this study do not support the idea that caffeine withdrawal is necessary or effective for inducing an ergogenic effect during a race. Regardless of the habitual caffeine intake or acute dose taken, an ergogenic effect was noted as long as the acute dose was below 6 mg/kg body weight. As a useful reference, we have included a table of popular caffeinated beverages from Harvard University School of Public Health.
Caffeine content in popular drinks
Drink | Caffeine content |
Medium 8 oz coffee | 95mg |
Single espresso (1.5 ounces) | 65mg |
Black tea | 47mg |
green tea | 28mg |
Coke (12 oz) | 40mg |
Medium energy drink (16 oz) | 170mg |
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Conclusions
In miniature, the study is good news for many athletes who drink coffee daily. Anyone who has experienced the side effects of caffeine withdrawal—headaches, drowsiness, indigent concentration, low mood, anxiety, and irritability—should be excited now. Caffeine withdrawal can be tough enough, so there’s no need to add caffeine withdrawal to the mix.
To get the most out of your caffeine intake, it would be a good idea to experiment with caffeine doses of 2-6 mg/kg of body weight during training to determine how it affects you personally. Some athletes feel extra nervous on race day, which may or may not be a good thing for peak performance. It has been suggested that not all athletes respond to caffeine in the same way and that genotype may influence this reaction. However, until you know your genotype, working with a sports dietitian and tracking your individual response to different caffeine levels within the suggested range can facilitate you identify the caffeine strategy that offers the greatest potential performance benefits.