Caffeine and Exercise

Caffeine has a deep evidence base for improving alertness, reaction time, endurance, and perceived exertion. Commonly studied doses fall in the range of three to six milligrams per kilogram of body weight taken before exercise.

The benefit that matters most for fat loss is indirect. Feeling capable of a full session means more completed training volume, and more training volume supports muscle retention while dieting.

Timing is the main practical constraint. Caffeine has a long half-life, so afternoon and evening servings can meaningfully degrade sleep quality — and poor sleep undermines appetite regulation and training recovery.

Count all your sources. Coffee, tea, pre-workout, energy drinks, and thermogenic capsules add up quickly, and tolerance varies widely between individuals.