Caffeine Before Exercise
Research has shown that pre-exercise caffeine enhances performance in sprints, in all-out efforts lasting four to five minutes, and in prolonged endurance activities. In shorter events, caffeine apparently increases muscle recruitment, which ultimately boosts performance. In longer events, it delays fatigue by reducing the athlete’s perception of effort. Caffeine does this by increasing the concentration of hormone-like substances in the brain called ß-endorphins during exercise. The endorphins affect mood state, reduce the perception of pain, and create a sense of well-being.
The performance-enhancing effect of caffeine is dose-dependent. The maximum benefit is seen with doses of 5 to 6 milligrams per kilogram of body weight. For a 150-lb person that translates to roughly 340-400 mg, or the amount of caffeine you’d get in 14 to 17 ounces of drip brewed coffee.
But here’s the catch—and it’s a big one: Caffeine only aids the performance of athletes who do not habitually use caffeine. So if you are a regular coffee drinker and want to benefit from a caffeine boost, you need to cut out the caffeine for one week before a big race, then dose up as described above on race morning. Also, note that caffeine pills such as NoDoz appear to have a stronger effect than coffee, so be careful not to over-consume.