Caffeine

Does it work?

• -Yes. Caffeine is one of the few supplements with strong, repeatable evidence across strength, endurance, and training quality. It reliably boosts power output, reps to failure, and focus — and the effect shows up the same session you take it.

How much · when

• -Dose 3-6 mg/kg of body weight (about 200-400 mg for most people). Higher doses rarely help more and add jitters.
• -Take it 30-60 minutes before training so blood levels peak when you start.
• -Coffee works, but a pill or powder makes the dose precise. ~1 strong cup of coffee is roughly 100 mg.
• -Cycle off or use the lowest effective dose on easy days — daily high intake builds tolerance and dulls the boost.

Safety

• -Late-day doses wreck sleep — caffeine has a ~5-hour half-life, so a 4pm dose is still half in your system at 9pm. Poor sleep cancels any training benefit.
• -Can cause jitters, racing heart, and anxiety, especially above 6 mg/kg. Start low to find your tolerance.
• -If you have a heart condition, high blood pressure, or are pregnant, check with a doctor on a sensible limit.

Key research

• International society of sports nutrition position stand: caffeine and exercise performanceJ Int Soc Sports Nutr · 2021 · Position stand
• Wake up and smell the coffee: caffeine supplementation and exercise performance-an umbrella review of 21 published meta-analysesBr J Sports Med · 2019 · Systematic review
• The effect of caffeine supplementation on muscular strength and endurance: A meta-analysis of meta-analysesHeliyon · 2024 · Meta-analysis
• Does ergogenic effect of caffeine supplementation depend on CYP1A2 genotypes? A systematic review with meta-analysisJ Sport Health Sci · 2024 · Meta-analysis

Related