Short answer
Take EAAs when it is convenient and consistent: before, during or after training all have support. A meta-analysis found that once total protein was accounted for, timing around workouts made no significant difference to muscle size or strength. The ISSN suggests spreading protein doses every 3 to 4 hours.
What the timing research found
A meta-analysis of randomized trials looked at protein taken around training. A simple analysis showed a small to moderate effect on muscle size, but once the authors accounted for total protein intake, the timing effect disappeared. Total protein was the strongest predictor of muscle growth (Schoenfeld 2013).
The ISSN position stand reaches a similar view: benefits come from pre- or post-workout protein, the window is probably a matter of individual tolerance, and the anabolic effect of exercise lasts at least 24 hours (ISSN 2017).
The common windows
EAA timing options
| When | Why people choose it | Watch for |
|---|---|---|
| Before training | Amino acids are in the blood as you train | Flavored products with caffeine add to pre-workouts |
| During training | Easy to sip in long sessions; light on the stomach | Sweeteners on a sensitive stomach |
| After training | Fits the classic recovery routine | If a meal follows soon, the EAA may be redundant |
| Between meals | Spreads protein through the day | Counts toward your total; no magic in itself |
| Fasted training | Some want amino acids without a meal | It ends a strict fast; see the fasting guide |
If you train fasted, read EAAs while fasting first.
A simple routine
Get your daily protein right first
The ISSN suggests 1.4 to 2.0 g of protein per kg of body weight a day for most exercising people.
Spread doses
Aim for protein every 3 to 4 hours, per the ISSN. An EAA can fill a gap between meals.
Use the training window if it helps
Sip during or take right after a session if that is when you would otherwise go without protein.
Stay consistent
The same time each day is easier to keep than a perfect window.
Makes it easier
Questions people ask
Is it better to take EAAs before or after a workout?
Either can work. The ISSN says benefits come from pre- or post-workout intake and that the effect of exercise on muscle lasts at least 24 hours. Pick the time you will stick to.
Can I take EAAs on rest days?
Yes. Muscle protein turnover continues on rest days, and the ISSN suggests spreading protein across the day. Rest days are a common time to use EAAs between meals.
Can I take EAAs before bed?
You can, if the product has no caffeine. Research on pre-sleep protein mostly used 30 to 40 g of casein, not EAAs.
Should I take EAAs with food?
Labels vary. Many people take them between meals so the dose stands apart from food protein. If a supplement upsets your stomach, taking it with food may help.
Sources
Last reviewed October 12, 2026. Formulas, labels and listings change; check the current label before you buy. This page is general information, not medical advice.