The world’s most widely used drug can be beneficial for runners.

Caffeine is the most widely used drug in the world. Despite the negative connotations of the word drug, however, caffeine is by and large a benign and even beneficial substance for humans.  “Acute caffeine consumption”—the scientific term for drinking a cup of coffee—has been shown to enhance mental alertness and mood state and is also known to boost athletic performance.  “Chronic caffeine consumption”—the scientific term for drinking a cup of coffee every morning—has been associated with a reduced risk for a number of disorders including type 2 diabetes, gallstones, and Parkinson’s disease. Not too shabby.

While moderate caffeine consumption is deemed best, even fairly high levels of regular caffeine use are not associated with any significant health risks. That said, it certainly is possible to consume too much caffeine, and some caffeine-sensitive individuals react poorly to even small amounts of the stimulant. But the bottom line is that caffeine can be boon to the runner before, during, and even after a workout or race. Here’s how:

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.

Caffeine During Exercise

A recent study, conducted at the University of Birmingham in England, looked at a completely different benefit of caffeine. It studied the effect the stimulant had during exercise on exogenous carbohydrate oxidation—which is the rate at which consumed carbs are burned.

Cyclists received either a 6-percent glucose solution, a 6-percent glucose solution plus caffeine, or plain water during a two-hour indoor cycling test. The researchers found that the rate at which the consumed carbohydrates were burned was 26 percent higher in the cyclists receiving carbs with caffeine than in those receiving carbs without caffeine. The study’s authors concluded that caffeine may have increased the rate of glucose absorption in the intestine, providing fuel to the working muscles more quickly. The likely effect on performance is the ability to work harder for a longer period of time without becoming fatigued.

Based on these results, athletes might want to consider consuming caffeine along with a sports drink during races or long training sessions instead of dosing up beforehand, since taking in caffeine both before and during a race or workout would be excessive and could lead to nervousness, anxiety, and stomach upset.

Caffeine After Exercise

Here we’re not talking about consuming caffeine after exercise to produce a benefit, but rather how taking in caffeine before a workout may make you feel better after the workout. A recent study from the University of Georgia found that pre-exercise caffeine intake reduced post-exercise muscle soreness by 50 percent. This is another effect that is unlikely to be felt by regular caffeine users, however. So again, wean yourself off caffeine for one week before big races or an important marathon training run, dose up that morning, and expect to not only perform better but also to experience faster muscle recovery afterward.

[sig:MattFitzgerald]