Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass: A systematic review and meta-analysis of randomized clinical trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 35986981 · doi:10.1016/j.nut.2022.111791
What was done
Following PRISMA guidelines, researchers searched PubMed, SPORTDiscus, Web of Science, and Scopus through May 2022 for randomized controlled trials (RCTs) assessing the effect of creatine supplementation on lean body mass (LBM). Studies in animals or individuals with specific diseases were excluded. Subgroup analyses evaluated the influence of exercise modality (resistance training, mixed exercise, or no exercise), age, and biological sex.
What was found
Across 35 included RCTs (n = 1,192), overall creatine supplementation increased LBM by 0.68 kg (95% CI, 0.26 to 1.11). - When combined with resistance training, LBM significantly increased by 1.10 kg (95% CI, 0.56 to 1.65), regardless of age. - When combined with mixed exercise, the effect was not statistically significant (MD, 0.74 kg; 95% CI, -3.89 to 5.36). - Without exercise, no significant change occurred (MD, 0.03 kg; 95% CI, -0.65 to 0.70). - By sex, males taking creatine gained 1.46 kg of LBM (95% CI, 0.47 to 2.46), whereas the increase in females was not statistically significant (MD, 0.29 kg; 95% CI, -0.43 to 1.01).
Why it matters
This review shows that creatine-mediated increases in lean mass are dependent on concurrent resistance exercise rather than supplementation alone. It also indicates that males experience substantially larger lean mass gains than females under these conditions.
Limits
The abstract does not specify dosing protocols, trial durations, compliance rates, or methods used to measure LBM across trials. Furthermore, total LBM measurements cannot differentiate between muscle protein accrual and intracellular water retention. Individuals with specific clinical conditions were excluded, limiting generalizability to healthy populations.
Cited by
- partial Meta-analyses show that creatine supplementation reduces fat mass while increasing lean mass, strength, endurance, and performance in females.
- supports Creatine supplementation combined with resistance training increases lean mass by an average of about 1.2 kg.