Caffeine

What is caffeine? The definition in 20 seconds

Caffeine blocks the action of adenosine, a messenger that signals fatigue to your brain. You feel more alert, and many find hard sets feel easier with it. That is your perceived exertion, the RPE. In studies caffeine improves strength, muscular endurance, movement velocity and jump power, but only by a small to moderate amount.

• A small effect, not a foundation: Caffeine gets a little more out of a session. It does not build muscle. Training, calories and sleep do that.
• Dose by bodyweight: The well-studied range is 3 to 6 mg per kg of bodyweight. More mostly brings side effects.
• For hardgainers this means: Use caffeine deliberately before hard sessions and protect your sleep. A short night costs you more than any cup gives back.

The anchors in the system: RIR for set intensity, SRA for recovery and your circadian rhythm for timing.

Caffeine and muscle growth: what you control and what you don't

How strongly caffeine works for you is not up to you. Genetic differences in how you break it down and your habits play a part. What you control is dose, timing and total intake.

• Dose: Start at the low end, around 3 mg per kg. Only go higher once you notice it works for you. Very high doses such as 9 mg per kg mostly bring side effects.
• Timing: The most common timing is about 60 minutes before the session. Test it on a hard training day, not before a max test.
• Deadline: No caffeine from the afternoon on. In one study, 400 mg still disturbed sleep when taken 6 hours before bed. How your sleep timing works is covered under melatonin.
• Total intake: Add up every source: coffee, tea, energy drinks, pre-workout. Combine three of them and you reach a high dose faster than you think.
• Targeted, not maxed daily: Many notice caffeine works less when they drink a lot every day. Save it for your heavy sessions.

Caffeine dose by bodyweight

The 3 to 6 mg per kg corridor converted into milligrams. Hardgainers are often light, so you usually need less than an energy drink can suggests.

The upper end is not a target. If 3 mg per kg does the job, stay there. Coffee varies a lot in strength, one cup is not a fixed dose.

Practice: the 14-day check

• Day 0, set your base: Set your caffeine deadline, work out your dose for hard sessions by bodyweight, lock in your sleep window.
• Document daily: Caffeine in mg with the time, when you fell asleep, sleep quality on a scale of 1 to 10, load and reps on your main lifts and steps as your measure for NEAT. How much your steps burn is shown by the NEAT Calculator.
• Day 14, check the trend: Falling asleep later or waking up unrested? Move your deadline earlier and lower the dose. Performance holds with less caffeine? Then you do not need the higher dose.

Sleep is the strongest legal booster. Caffeine is the add-on, not the base.

Common misconceptions

• “More caffeine means more performance.” No. Above the 3 to 6 mg per kg corridor, mostly the side effects go up: restlessness and poor sleep.
• “Coffee in the evening doesn't affect me.” Even if you think you fall asleep fine, your sleep can suffer. In one study, 400 mg measurably disturbed sleep even when taken 6 hours before bed.
• “Morning coffee ruins my cortisol.” How strongly cortisol reacts to caffeine is individual. Total stress, sleep and recovery matter more.
• “Coffee replaces my breakfast.” Many hardgainers start the day with coffee instead of food and notice that hunger then stays away until lunch. For your surplus, that is a lost meal.

Common questions