Me: Duh. Via NPR:
After winning the Tour de France last Sunday, Vincenzo Nibali was tested for a bunch of performance-enhancing substances. But Nibali and his fellow competitors were welcome to have several cups of coffee (or cans of Red Bull), before their ride into Paris; caffeine is not on the World Anti-Doping Agency’s banned list.
Still, the drug is definitely a performance booster. Just in the past few months, studies have shown that caffeine helps female volleyball players hit the ball harder and jump higher, rowers go farther, and cyclists go faster in a 20K time trial.
A large body of research shows caffeine helps in “pretty much every kind of endurance exercise,” giving a performance advantage of 1.5 percent to 5 percent, says Mark Glaister, an exercise physiologist at St. Mary’s University in Twickenham, U.K., and an author of the recent cycling study.
The rest here.