Research

Hormonal

Ingesting 9 mg/kg of caffeine one hour before prolonged endurance exercise significantly increases time to exhaustion in trained runners.

If you are a trained runner, taking 9 mg of caffeine per kg of body weight one hour before your event can significantly extend how long you can exercise. For a 70 kg person, this is 630 mg. Ensure you have abstained from caffeine for 48 hours prior to maximize the effect, and consume a high-carbohydrate diet as usual.

GoodSupportsHIGH confidence
Endurance times were increased (P < 0.05) after CAF ingestion during running (PL 49.2 ± 7.2 min, CAF 71.0 ± 11.0 min) and cycling (PL 39.2 ± 6.5 min, CAF 59.3 ± 9.9 min).
Terry E. Graham et al. · Journal of Applied Physiology · 1991

Why this rating

Randomized, double-blind, placebo-controlled trial with well-trained subjects, though small sample size (n=7).

Source

Performance and metabolic responses to a high caffeine dose during prolonged exercise

Terry E. Graham et al. · Journal of Applied Physiology · 1991

DOI 10.1152/jappl.1991.71.6.2292

crossover · n=7Cited 338×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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