Creatine: The Most Researched Sports Supplement and What It Actually Does

Creatine is a naturally occurring compound synthesised in the liver, kidneys, and pancreas from the amino acids arginine, glycine, and methionine. Approximately 95% of the body's creatine is stored in skeletal muscle as phosphocreatine (PCr), with the remaining 5% in the brain, heart, and testes.

During high-intensity exercise lasting 1-10 seconds — a sprint, a heavy lift, a jump — the body primarily relies on the phosphocreatine energy system. PCr rapidly donates a phosphate group to ADP to regenerate ATP, the cell's energy currency. This system depletes rapidly but recovers during rest.

Supplemental creatine increases muscle PCr stores by 10-40%, extending the duration of maximal power output before fatigue sets in. This is the core mechanism behind creatine's performance benefits.

Creatine is the most studied performance supplement in sports science, with over 500 peer-reviewed studies performed since the 1990s. The evidence for its ergogenic effects is among the strongest in all of nutritional research.

A meta-analysis by Rawson and Volek (2003) in *Journal of Strength and Conditioning Research* found that creatine supplementation increased maximum strength by an average of 8% and weightlifting performance (repetitions to failure) by 14% compared to placebo.

A comprehensive review by the International Society of Sports Nutrition (Kreider et al., 2017) in their *Journal of the International Society of Sports Nutrition* stated that creatine monohydrate is the most effective ergogenic nutritional supplement currently available for increasing high-intensity exercise capacity and lean body mass.

Beyond performance, creatine supplementation consistently increases lean body mass. A meta-analysis by Branch (2003) in *International Journal of Sport Nutrition and Exercise Metabolism*, reviewing 22 studies, found that creatine users gained an average of 2.2 kg more lean mass during training periods compared to placebo groups.

The mechanisms include: - Increased training volume: By allowing more reps and sets before fatigue, creatine enables greater training stimulus. - Cellular volumisation: Creatine draws water into muscle cells, increasing cell volume which may signal anabolic pathways. - Enhanced satellite cell activity: Some evidence suggests creatine increases the activity of muscle stem cells (satellite cells), supporting muscle repair and growth.

Weight gain of 1-2 kg in the first week of supplementation is primarily due to water retention in muscles, not fat gain.

An emerging and underappreciated area of creatine research is its cognitive benefits. The brain has high energy demands and contains significant creatine stores.

A systematic review by Avgerinos et al. (2018) in *Experimental Gerontology* found that creatine supplementation improved memory and intelligence/reasoning in healthy adults, with the largest effects seen in tasks requiring short-term memory and tasks performed under sleep deprivation or cognitive stress.

Research by McMorris et al. (2007) in *European Journal of Applied Physiology* found that creatine supplementation significantly reduced cognitive impairment during sleep deprivation — maintaining working memory and mood in sleep-deprived individuals.

Dosing: The simplest and most evidence-supported approach is 3-5g of creatine monohydrate daily, taken consistently. "Loading" (20g/day for 5-7 days) saturates muscle stores faster but produces the same long-term result as the lower dose.

Safety: Creatine monohydrate has one of the most extensive safety records of any supplement. The ISSN's position stand concludes that creatine is safe for healthy individuals across all ages, including adolescents and older adults, with no evidence of harm to kidney or liver function in people without pre-existing conditions.

Form: Creatine monohydrate is the best-studied and most cost-effective form. More expensive forms (creatine ethyl ester, buffered creatine) have not demonstrated superior benefits in head-to-head research.

- Creatine monohydrate is the most researched sports supplement, with over 500 peer-reviewed studies. - It increases strength by ~8%, power performance by ~14%, and lean mass by ~2 kg during training. - Brain health benefits include improved memory and reduced cognitive decline under stress. - 3-5g daily is the effective maintenance dose; loading is optional. - Creatine monohydrate is safe for healthy adults and is cost-effective compared to other forms.