Creatine: The Evidence for Cognitive and Physical Performance

What Creatine Actually Does

Creatine is a naturally occurring compound synthesized from glycine and arginine in the liver. Approximately 95% of total body creatine is stored in skeletal muscle; the remaining 5% resides in the brain, heart, and testes.

Its primary function is regenerating ATP — the universal energy currency of cells — during high-intensity efforts lasting 1–10 seconds. By maintaining ATP availability longer, creatine allows muscles to sustain maximum force output before fatigue sets in.

The Physical Performance Evidence

With over 500 published studies, creatine monohydrate is the most extensively researched performance supplement in existence. Meta-analytic data consistently show:

• 5–15% improvement in high-intensity exercise performance
• 1–2 kg increase in lean body mass over 4–8 weeks of training
• Faster recovery between sets, enabling greater training volume

These effects are relevant not only for athletes but for aging adults. Creatine combined with resistance training produces significantly greater gains in muscle mass and strength than resistance training alone in adults over 55.

The Cognitive Performance Data

The brain relies on rapid ATP regeneration, particularly during periods of cognitive stress, sleep deprivation, or aging. Three lines of evidence support creatine's cognitive benefits:

1. Mental fatigue: Studies show that creatine supplementation reduces the decline in cognitive performance during sleep-deprived conditions — a highly relevant finding for professionals working demanding schedules.

2. Processing speed: A meta-analysis found that creatine supplementation improved memory and intelligence test scores, with the largest effects seen in older adults and vegetarians (who have lower baseline creatine stores).

3. Depression and mood: Emerging research suggests creatine supplementation may augment antidepressant treatment efficacy, possibly through its role in frontal lobe energy metabolism.

Dosing and Safety

Protocol: 3–5 grams of creatine monohydrate daily. No loading phase necessary.

Timing: Any time of day. Consistency matters more than timing.

Form: Monohydrate is the only form with robust evidence. More expensive forms (HCl, ethyl ester) offer no demonstrated advantage.

Safety: Decades of safety data at these doses show no adverse effects on kidney or liver function in healthy individuals.