There’s a good chance the world’s most popular stimulant is part of your favorite pre-workout formula, because it’s been shown to help increase exercise performance while reducing the rate of perceived exertion. Now the question becomes how much is enough? A study published in the journal Medicine and Science in Sports and Exercise attempts to answer that question for the bench press and squats.

Researchers gave 13 experienced weight lifters a placebo or dose of caffeine equal to 3 mg, 6 mg or 9 mg per kg of body weight. Then they measured barbell velocity and muscular power during squats and the bench press using loads equal to 25%, 50%, 75% and 90% of one rep max (1RM).

Using lighter loads (25% and 50% of 1RM), all caffeine doses significantly increased barbell velocity compared to placebo, but 9 mg of caffeine per kg of body weight was needed to increase power at 90% of 1RM. As you might expect, large doses also increased the frequency of side effects.

True Strength Moment: For a 180 pound person, 3 mg per kg of body weight is 246 mg of caffeine, or about the same as 3 strong cups of coffee. 9 mg per kg of body weight would be a dose of 738 mg. Most people would have a hard time tolerating that amount. To find the dose that works best for you, start out with a low level and gradually increase as needed. Check out today’s Performance Blog at ABBperformance.com for a caffeine study on cross-country skiing.