How long it lasts
Caffeine’s half-life is about five hours on average, but it varies a lot between people, from roughly two to ten hours. Half of an afternoon coffee can still be in your system at bedtime.
For training
3–6 mg/kgis the studied performance dose
30–60 minbefore training is a common timing
400 mga day is the usual upper limit for healthy adults
Use it well
Do
- Keep a cut-off time 8–10 hours before bed
- Use lower doses on most days
- Save bigger doses for key sessions
Avoid
- Stacking pre-workout and coffee
- Caffeine to cover for poor sleep every day
- Energy drinks late in the day
Key takeaways
- Half-life is about 5 hours, longer for some people
- Have your last cup well before bed
- 3–6 mg/kg helps performance; more is not better
General information, not medical advice. If you have a health condition, are pregnant, or take medication, check with a professional first. See the medical disclaimer.
Sources
- Guest NS et al. ISSN position stand: caffeine and exercise performance. JISSN, 2021.
- EFSA Panel. Scientific opinion on the safety of caffeine. EFSA Journal, 2015.
- Drake C et al. Caffeine effects on sleep taken 0, 3 or 6 hours before going to bed. J Clin Sleep Med, 2013.