Absorption Timeline
How caffeine reaches peak concentration after ingestion — and when performance benefits begin
Optimal Dosage by Body Weight
The 3–6 mg/kg sweet spot — research-backed caffeine ranges for maximum ergogenic benefit
180mg
130–150 lb
~1.5 cups brewed coffee
240mg
150–180 lb
~2 cups brewed coffee
300mg
180–210 lb
~2.5 cups brewed coffee
360mg
210–240 lb
~3 cups brewed coffee
Performance Gains by Domain
Caffeine's measured impact across exercise categories — percentage improvements from meta-analyses
2–4%
Endurance
Time-to-exhaustion extended
3–6%
Strength
1RM max output increased
3–5%
Power
Explosive output elevated
7–12%
Reaction Time
Cognitive response faster
5–8%
Anaerobic
High-intensity capacity
20%
Fat Oxidation
Fat burning rate during cardio
Before vs. After Caffeine
Side-by-side: baseline performance vs. optimized caffeine protocol (3–6 mg/kg, 30–45 min pre-exercise)
Endurance (min to exhaustion)
No caffeine: 48 minWith caffeine: 52 min
Bench Press 1RM (lb)
No caffeine: 225With caffeine: 238
Sprint Power (watts)
No caffeine: 680With caffeine: 720
Reaction Time (ms)
No caffeine: 248With caffeine: 221
Data Sources
- Grgic et al. (2020) — "Caffeine supplementation and exercise performance," Journal of the International Society of Sports Nutrition, meta-analysis of 21 studies.
- Spriet (2019) — "Exercise and Sport Performance with Low Doses of Caffeine," Sports Medicine, 49(S2):161–174.
- Pickering & Kiely (2018) — "What Should We Do About Habitual Caffeine Use in Athletes?" Sports Medicine, 49(S1):31–44.
- Guest et al. (2021) — "International Society of Sports Nutrition position stand: caffeine and exercise performance," JISSN, 18(1):1.
- Graham & Spriet (1995) — "Performance and metabolic responses to a high caffeine dose during prolonged exercise," Journal of Applied Physiology, 78(3):867–874.
- Hodgson et al. (2013) — "The metabolic and performance effects of caffeine compared to coffee during endurance exercise," PLoS ONE, 8(4):e59561.