Research

Hormonal

Acute ingestion of 6 mg/kg caffeine potentiates skeletal muscle force output during low-frequency (20 Hz) stimulation, an effect mediated by enhanced calcium release from the sarcoplasmic reticulum, and this benefit occurs regardless of habitual caffeine consumption status.

If you consume caffeine regularly, you can still benefit from its performance-enhancing effects, specifically for endurance or submaximal efforts. Take 6 mg per kg of body weight about 1-2 hours before activity. This will help your muscles maintain force during prolonged, submaximal efforts by improving calcium release in the muscle cells, but it will not significantly boost your one-rep max or sprint power.

GoodSupportsHIGH confidence
Caffeine potentiated the force of contraction during the final minute of the 20-Hz stimulation (P < 0.05) with no effect of habituation. These data support the hypothesis that some of the ergogenic effect of caffeine in endurance exercise performance occurs directly at the skeletal muscle level.
Mark A. Tarnopolsky et al. · Journal of Applied Physiology · 2000

Why this rating

Double-blind, randomized, cross-over design with healthy subjects, though the sample size is small (n=12) and the outcome is acute neuromuscular function rather than long-term performance.

Source

Caffeine potentiates low frequency skeletal muscle force in habitual and nonhabitual caffeine consumers

Mark A. Tarnopolsky et al. · Journal of Applied Physiology · 2000

DOI 10.1152/jappl.2000.89.5.1719

crossover · n=12Cited 206×
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DOI resolved against Crossref · corpus check 2026-06-10

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