Exercise physiologists have studied caffeine’s effects in nearly every iteration: Does it help sprinters? Marathon runners? Cyclists? Rowers? Swimmers? Athletes whose sports involve stopping and starting like tennis players? The answers are yes and yes and yes and yes.
Starting as long ago as 1978, researchers have been publishing caffeine studies. And in study after study, they concluded that caffeine actually does improve performance. In fact, some experts, like Dr. Mark Tarnopolsky of McMaster University in Canada, are just incredulous that anyone could even ask if caffeine has a performance effect.“There is so much data on this that it’s unbelievable,” he said. “It’s just unequivocal that caffeine improves performance. It’s been shown in well-respected labs in multiple places around the world.”
Dr. Tarnopolsky and others report that caffeine increases the power output of muscles by releasing calcium that is stored in muscle. The effect can enable athletes to keep going longer or to go faster in the same length of time. Caffeine also affects the brain’s sensation of exhaustion, that feeling that it’s time to stop, you can’t go on any more. That may be one way it improves endurance, Dr. Tarnopolsky said.
The performance improvement in controlled laboratory settings can be 20 to 25 percent, Dr. Tarnopolsky said. But in the real world, including all comers, the improvement may average about 5 percent, still significant if you want to get your best time or even win a race.
Louise M. Burke, the head of sports nutrition department of the Australian Institute of Sport in Canberra, reports that athletes get the full caffeine effect with as little as 1 milligram of caffeine per kilogram of body weight. Instead of 20 ounces of coffee, a 176-pound man could drink 4 ounces of coffee, or about two 12-ounce cans of Coke.
SO would we do better if we weaned ourselves from caffeine and then took a pill or two before a race?
I asked Dr. Tarnopolsky. It turns out, he said, that you get habituated to two of caffeine’s effects right away. Caffeine can make you urinate, but only if you are not used to it.
“Athletes do not get dehydrated from caffeine,” he added, “contrary to popular myth.”The beneficial effects on exercise, though, remain. Even if you are a regular coffee drinker, if you have a cup of coffee before a workout or a race, you will do better, Dr. Tarnopolsky said. “There is no question about it,” he added.