Mixed
Acute caffeine ingestion (2.5–7 mg/kg) significantly improves performance in short-term high-intensity exercise (sprinting, team sports, resistance training), with effects being more pronounced in trained athletes and non-habitual users.
If you are a trained athlete engaging in short, high-intensity efforts (like sprinting or heavy lifting), taking 3-6 mg of caffeine per kg of body weight about 45-60 minutes before exercise can improve performance by roughly 6-9%. This benefit is strongest if you are not a heavy daily coffee drinker. If you are untrained or doing long endurance, the benefit is less clear. Avoid doses above 9 mg/kg to prevent side effects like anxiety.
Eleven of 17 studies revealed significant improvements in team sports exercise and power-based sports with caffeine ingestion, yet these effects were more common in elite athletes who do not regularly ingest caffeine. Six of 11 studies revealed significant benefits of caffeine for resistance training.
Why this rating
Based on a systematic review of 28 studies with a mean PEDro score of 7.76, indicating high methodological quality.
Source
Efficacy of Acute Caffeine Ingestion for Short-term High-Intensity Exercise Performance: A Systematic Review
Todd A. Astorino et al. · The Journal of Strength and Conditioning Research · 2010
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