Caffeine isn’t just for waking up. For recreational and elite athletes, it’s one of the most popular performance supplements. A study published in the journal Physiology & Behavior tested caffeine’s effect on 16 endurance trained athletes and recreationally active men.

Because so many studies have tested caffeine during steady-state exercise, researchers designed this study around race performance. Just before competing in a 10 km time trial, subjects were given either a placebo or a drink containing 5 mg of caffeine per kg of body weight (350 mg for someone weighing 154 lbs). After several trials separated by at least 48 hours for recovery, those who had a caffeinated beverage reported feeling more pleasure than discomfort compared to placebo. Caffeine also enhanced race performance up to 2%. The effect was strongest in well-trained athletes.

True Strength Moment: Getting to the finish line 2% faster is a huge advantage for the professional cyclist. It might not make that much of a difference to someone who’s just trying to stay in great shape, but being able to enjoy the challenge that much more certainly has its advantages. We suggest testing your performance with a lower dose. Start with maybe 100 mg of caffeine, which represents about what you’d get from a strong cup of coffee. You can work your way up from there if you think it’s necessary.