Ask the Coach: Should I Cut Caffeine Before A Race?

Some athletes swear by cutting out caffeine in the days or weeks before a race. But what does the science say?

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A number of my ultra friends quit caffeine a week or two before a big race so that it’s got more “punch” for them on race day. Is it worth it?

—Robyn Reed, Minneapolis, MN

Aside from providing a daily wake-up for many of us, caffeine reduces perceived exertion, essentially making athletes feel more “aroused” while exercising, as described in the journal Appetite in 2011. Caffeine may also have positive effects for muscle metabolism (increasing fat burning and sparing glycogen), though studies are inconclusive.

How important is “arousal”—i.e., energy activation over a baseline state—to your relationship with running? Various studies indicate that caffeine can improve performance by as much as five to 10 percent over a placebo. The effects are more pronounced during longer activities like ultras.

RELATED: Ask The RD – Caffeine And Performance

When it comes to strategically cutting back, things get tricky. Most studies deprive one cohort of athletes of caffeine, which may end up measuring withdrawal as much as arousal. The general recommendation from years of literature is to abstain for three to four days prior to competition for maximum effect.

However, a 2011 study in the Journal of Sports Sciences might refute that advice. Study participants were split into four groups: those who abstained and then consumed, just abstained, consumed then abstained, and consumed the whole time. The participants who had caffeine on race day saw a three-percent performance improvement regardless of whether they had abstained in the days prior. (Notably, some Americans drink far more caffeine than was administered in the study, so the findings might not apply if you drink a pot a day.)

So the conclusion of all of the studies and anecdotes is that you should find what works for you. Caffeine usually improves performance, and, according to studies, one to two cups of coffee (around 200 milligrams of caffeine) is ideal on race day, depending on your weight and tolerance. Cutting back in the three to four days prior to a race could help, though don’t make your life miserable by worrying too much about maximizing performance benefits. In any case, it’s a good idea to at least keep your intake moderate in the days before a race, so you’re not consuming more than you will have on race day.

RELATED: What Matters (And What Doesn’t) Before A Race

This article originally appeared in our September 2016 issue. Have a question for Coach Roche? Email it to us:

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