Caffeine (standardised)

Tier 1 — strong evidence · Performance · Alertness · Endurance

The world's most widely consumed psychoactive compound and one of sport science's most evidence-backed ergogenics. The 2021 ISSN position stand (Guest et al., PMID 33388079) confirms 3-6 mg/kg body weight improves muscular endurance, movement velocity, strength, sprinting, jumping, and aerobic performance. Minimal effective dose may be as low as 2 mg/kg. Cognitive benefits — attention, vigilance, psychomotor speed — are well established and apply even under sleep deprivation. Tolerance develops with habitual use, reducing ergogenic magnitude. Caution: disrupts sleep when taken within 6-8…

Dose: 3-6 mg/kg body weight 45-60 min before exercise or a demanding cognitive task (approximately 200-400 mg for most adults). Do not exceed 400 mg/day. Doses above 6 mg/kg increase side-effects without additional benefit.