Q. Can caffeine improve athletic performance?
A. In some cases. Researchers often classify caffeine as an “ergogenic” (performance-enhancing) aid. Many studies have found that even 200 milligrams (about two cups of coffee) can boost endurance, reduce fatigue, and/or improve sprint performance, at least in trained athletes.
But some studies have found little or no benefit. In any case, what happens in the controlled conditions of a study may not happen in a real sporting event or on a brisk four-mile walk.
Experts theorize that caffeine helps the body break down fats and burn them for energy. But its chief effects may be on the nervous system—caffeine interacts with various brain chemicals to reduce fatigue.
It can also make a workout feel easier, so you’re able to exercise more strenuously and/or longer.
It’s well known, of course, that caffeine improves alertness, wakefulness and performance on mental tasks. The mental and physical effects vary widely, however, depending especially on whether you consume caffeine regularly or not.
Drinking some coffee or tea before your workout might help you feel more energetic, but doubling the dose of caffeine won’t turn you into Michael Jordan.
And if you are unaccustomed to it, swallowing 200 milligrams of caffeine before you exercise might give you coffee nerves and hinder your performance.