Ask Stacy: Should I Abstain from Caffeine Before a Race?

Caffeine is one of the most studied and widely consumed psychoactive substances around and it’s often cited as an endurance athlete’s best friend. Why? Because caffeine’s stimulatory effect on the central nervous system has been shown to reduce feelings of fatigue, lower perceived exertion, and even lower levels of perceived pain. Caffeine also improves mental acuity and sharpness, it helps maintain laser-like focus, and it even boosts some technical skills both during and after strenuous activity. And, if that isn’t enough, it’s also believed to enhance the body’s ability to use its own fat as fuel, which can effectively increase the time to exhaustion in endurance events.

The theory behind abstaining from caffeine for a period of time before a race in order to get a bigger boost stems from theory of “habitual tolerance”—the idea being that if you are a daily caffeine user, then you will not get a huge ergogenic effect from caffeine on race day, since you’re accustomed to it.

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Research set out to test this theory and determine what, if any, effect abstaining from caffeine before a race might have on that endurance performance boost. The abstinence periods studied varied from 12 hours to 48 hours to four days, and let’s just say the results were a bit more complex than a simple yes or no answer to the question. For example, in shorter abstinence periods (12 to 48 hours), being given an acute dose of caffeine before a time trial did improve performance, but that was because it was primarily associated with alleviating the negative symptoms of caffeine withdrawal.

However, in another study, trained male cyclists were given 3mg of caffeine per kilogram of bodyweight and it significantly improved their performance—irrespective of whether a four-day withdrawal period was imposed. Another study also reported increased endurance in habitual caffeine users regardless of a two- or four-day abstinence period or no abstinence period. It was concluded that improved performance using caffeine was not related to prior caffeine habituation.

A better method to stimulate the ergogenic effect of caffeine without giving up your daily habit is to better time the ingestion. General practice is to take your caffeine about an hour before the race starts, mostly because of the belief that plasma levels of caffeine peak about 60 minutes after you take it. However, the source, the amount, and your genetics can all affect how fast that caffeine peaks. For example, caffeine chewing gum absorbs faster than caffeine tablets, and caffeinated drinks fit somewhere in between. Strategic dosing during your race can give you a boost when you most need it with a low dose (25-50mg), even if you are a habitual caffeine user.

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A recent review also indicated that the performance boost of caffeine goes up with the increasing duration of the event, meaning that you want to use a small amount of caffeine in the later stages of your race when fatigue is near its highest point. Note here, research found that a cup of flat Coke toward the end of a race gives comparable effects to a high dose of caffeine taken toward the start—and that’s not from the carbohydrate content, but from the small dose of caffeine.

Bottom line—and it’s good news—you do not need to abstain from your morning coffee to get a performance boost during your next race. Just time your intake for optimal effect.

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