Caffeine before a workout
Caffeine is the most accessible supplement that actually helps in the gym: a few more reps, heavy sets that feel a bit lighter. The trick is the dose and the timing, so you don't pay for it with your sleep.
What caffeine does
The ISSN position stand on caffeine (Guest et al., 2021) calls it an effective supplement for many kinds of exercise. For lifting, that means a few more reps to failure, a little more strength and power, and less sense of effort: the same set feels lighter.
The effect is small — it won't add 20 kg to your bench. But on a heavy day a couple of extra reps add up to extra volume, and on a max attempt to an extra chance.
Testing it on yourself is easy: add a note to the workout saying whether you had coffee, and after a couple of weeks compare your sets in the diary.
How much to take
In research, 3–6 mg of caffeine per kg of bodyweight works. For 70 kg that's 210–420 mg; for 80 kg, 240–480 mg. The ISSN position stand notes that lower doses, around 2 mg per kg, can work too, while very high doses bring side effects more often than benefits.
Start at the low end — 3 mg per kg or less — and see how your sets go. Raise the dose only if there's no difference and your heart, sleep and stomach aren't complaining. More isn't better: shaky hands and jitters hurt the bar more than the buzz helps.
When to take it
Usually about 60 minutes before training: that gives caffeine time to absorb by your first working sets. Caffeine gum kicks in faster than a drink.
A simple routine: coffee on the way to the gym or an hour before you leave, then your warm-up and working sets. If you drink it right before the bar, the peak lands at the end of the workout.
Where to get the dose
- Coffee — a cup of brewed coffee has roughly 80–120 mg, but it varies a lot: the beans, the grind, the size of the cup.
- Caffeine pills — an exact dose, handy if you want to know how much you took.
- Pre-workouts — caffeine plus everything else. Check how much caffeine is in a serving: 300 mg or more isn't unusual.
- Energy drinks — caffeine plus sugar; go by the label.
Don't stack sources blindly: coffee in the morning, a pre-workout before the gym and an energy drink after is already a lot.
Sleep matters more
Caffeine stays in your blood for hours, and for many people an evening dose eats into deep sleep even if they fall asleep fine. And poor sleep takes more from your training than caffeine gives: recovery, strength next week, appetite.
Training in the evening? Take less, move your coffee earlier in the day or skip it. Test it on yourself: if you wake up wrecked after evening coffee, the honest answer is no.
Tolerance
You get used to the buzz quickly: morning coffee stops hitting. The effect on training is a different story: the ISSN position stand considers that in regular coffee drinkers the performance boost usually remains, though the data here are mixed.
If your dose feels like it stopped working, don't keep raising it. A couple of weeks on less caffeine and your usual dose will feel like something again. Saving caffeine for heavy training days instead of three cups every day is a simple way to keep it working.
Safety
For healthy adults, about 400 mg of caffeine a day is considered safe — that's the figure food safety agencies go by. Pre-workout doses for a heavier lifter easily get close to that ceiling, so count all the caffeine in your day, not just before the gym.
Heart disease, high blood pressure, anxiety, pregnancy, medication — talk to a doctor first. I'm a coach: these numbers are for healthy adults.
Common questions
Does it work for everyone? Responses vary: some people get a clear boost, others almost nothing. Test it on yourself with your log.
Can I take it with creatine? Yes, they work in different ways. You take creatine every day and caffeine before training. More in the guide on creatine.
Is a workout without caffeine a waste? No. It's a small boost, not the foundation. The foundation is your program, food and sleep — more in the guide on supplements that work.
Coffee or a pre-workout? For the caffeine itself there's no difference: the caffeine does the work, not the rest of the mix. Coffee is cheaper; a pre-workout is handier if you want to know the exact dose — check the label.
Log your workouts — compare your sets on days with and without coffee: the diary shows whether it gets you more reps.
Prefer Telegram? Open the bot — same diary.