Research

Hormonal

Caffeine improves neuromuscular performance during single all-out muscle contractions, but the required dose is load-dependent: 3 mg/kg suffices for low loads/high velocity, while 9 mg/kg is required for high loads/low velocity.

If you are lifting heavy weights (near your max), you need a high dose of caffeine (9 mg/kg) to see a performance boost, but be prepared for potential side effects like anxiety or sleep issues. If you are doing lighter weights at high speed (e.g., Olympic lifts, plyometrics), a lower dose (3 mg/kg) is sufficient and less likely to cause side effects. Take it 60 minutes before your workout.

GoodConditionalHIGH confidence
A dose of 3 mg/kg is enough to improve high-velocity muscle actions against low loads, whereas a higher caffeine dose (9 mg/kg) is necessary against high loads, despite the appearance of adverse side effects.
Jesús G. Pallarés et al. · Medicine & Science in Sports & Exercise · 2013

Why this rating

Randomized, double-blind, crossover design with resistance-trained subjects, though small sample size (n=13).

Source

Neuromuscular Responses to Incremental Caffeine Doses

Jesús G. Pallarés et al. · Medicine & Science in Sports & Exercise · 2013

DOI 10.1249/mss.0b013e31829a6672

crossover · n=13Cited 174×
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DOI resolved against Crossref · corpus check 2026-06-10

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