Creatine in humans with special reference to creatine supplementation.
Level 5 - mechanism / opinion, no new human data
Narrative review of human metabolism and supplementation studies without systematic methodology.
PubMed 7817065 · doi:10.2165/00007256-199418040-00005
What was done
This narrative review summarizes human research on creatine metabolism, tissue distribution, dietary intake, and the effects of exogenous creatine supplementation on exercise performance and clinical conditions.
What was found
Over 95% of human body creatine is stored in skeletal muscle (roughly one-third free, two-thirds phosphorylated), with an estimated daily turnover of approximately 2 g in a 70 kg male. Supplementation increases muscle free and phosphorylated creatine concentrations and enhances high-intensity intermittent exercise performance. However, it does not appear to enhance endurance performance or maximal oxygen uptake. No adverse effects were reported from short-term feeding.
Why it matters
The paper synthesizes foundational evidence showing that creatine supplementation selectively benefits short-duration, high-intensity anaerobic performance rather than aerobic endurance.
Limits
The review is narrative rather than systematic, offering no explicit search criteria, study counts, or quantitative effect sizes. Long-term safety and specific dosing protocols are not detailed in the abstract.
Cited by
- context A standard serving of salmon contains approximately 3 to 4 grams of creatine.