“Can caffeine improve your exercise performance?”

Yes. Though not that much.

How?

“During waking hours, adenosine slows down brain activity and results in feelings of fatigue. When we have caffeine, the caffeine binds to the adenosine receptors and has the opposite effect of adenosine. It reduces fatigue and our perception of effort (for example, how hard it feels to perform an exercise).”

How much?

“Experts believe caffeine doses between 3 and 6 mg/kg are needed to improve performance. That’s 210 to 420mg for a 70kg person, or about two cups of coffee.”

“Those who respond most strongly to caffeine might see improvements of around 16%, but this is unusual. For the average person, improvements will likely be between about 2% and 6%.”

When?

“Experts believe caffeine doses between 3 and 6 mg/kg are needed to improve performance. That’s 210 to 420mg for a 70kg person, or about two cups of coffee.”