A new meta-analysis reveals that while creatine consistently boosts high-intensity performance, its muscle-building potential depends on pairing supplementation with the right type of training.
Study: Creatine supplementation in young men under resistance versus non-resistance training: a systematic review and meta-analysis of strength, performance, and lean mass. Image credit: djavan rodriguez/Shutterstock.com
Researchers have recently conducted a systematic review and meta-analysis to examine whether the effects of creatine supplementation on body composition and anaerobic performance differ between resistance-trained and non-resistance-trained populations. The findings of this study were published in Frontiers in Nutrition.
Creatine Supplementation, Training Context, and Gaps in the Evidence
Creatine is a naturally occurring compound found primarily in skeletal muscle, with smaller amounts present in the brain, heart, and testes. Dietary intake accounts for 60–80 % of total creatine and phosphocreatine (PCr) stores, and exogenous supplementation can further increase intramuscular creatine and PCr by 20–40 %.
The phosphocreatine (PCr)-creatine kinase system is responsible for rapidly restoring ATP, the body’s primary energy currency, during short bursts of high-intensity activity. It is this energy-replenishing role that explains why creatine is so widely used as a performance-enhancing supplement.
Randomized Controlled Trials (RCTs) and meta-analyses have consistently shown that creatine’s benefits on maximal strength are greatest when combined with structured resistance training (RT). This could be attributed to the fact that creatine improves training quality, high-intensity load tolerance, and recovery, collectively driving enhanced neuromuscular adaptations.
Creatine’s effects on body composition, and lean mass in particular, are less consistent than its strength benefits. Systematic reviews report modest increases in lean body mass (LBM) and fat-free mass (FFM), though considerable between-study heterogeneity exists. Differences in participant characteristics, supplementation protocols, training modalities, and assessment methods all contribute to this variability. The training modality is typically examined only through post hoc subgroup analyses in mixed-sex, broad age-range reviews, which limits the specificity and practical relevance of the conclusions.
Training context is an underexplored but probable modifier of creatine’s effects, as the type of training shapes the adaptive pathways through which creatine’s metabolic benefits are expressed. However, existing reviews and meta-analyses have largely treated this factor as secondary rather than as a prespecified analytical framework, conflating diverse populations and training approaches, and often evaluating performance and body composition outcomes separately, leaving its moderating role in young men unresolved.
Study Design and Data Sources
This systematic review and meta-analysis synthesized RCTs in healthy men aged 18 to 30 years to evaluate the effects of creatine supplementation on maximal strength, anaerobic performance, and lean mass, including LBM and FFM. Eligible trials required creatine supplementation at any dose or regimen in combination with a clearly defined training stimulus. Any nonrandomized study or one lacking a control group was excluded.
The comparator was a creatine-free control condition, with training frequency, intensity, periodization, and supervision matched between groups that included exercise. Studies were required to report at least one extractable primary outcome, including maximal lower-body strength via one-repetition maximum (1RM), countermovement jump (CMJ) performance, Wingate peak or mean power, or lean mass assessed as LBM or FFM.
All relevant papers were obtained from PubMed, Web of Science, Scopus, Embase, the Cochrane Library, and SPORTDiscus from inception to October 2025. During data extraction, eligible trials were classified by training context as RT or non-RT for stratified analyses.
Creatine Supplementation Improves Strength and Anaerobic Power, with Body Composition Benefits Specific to Resistance Training
A total of 39 RCTs met the eligibility criteria and were included in the analysis. It included 25 RT and 14 non-RT studies, with participants aged 18.0 to 29.5 years and training status ranging from sedentary to elite. Exercise modalities included RT, team and individual sports, cycling-based protocols, and strength or power assessments.
Creatine was given either as a loading dose (20 g/day for 5–7 days) followed by a maintenance dose, or as a fixed daily amount, over periods ranging from 4 days to 12 weeks. Control conditions consisted predominantly of carbohydrate-based placebos or inert substances, with a minority of studies using protein or carboxymethylcellulose as comparators.
Approximately 64 % of trials were at low risk of bias, with some concerns in 28 % and high risk in 8 %. Outcome measurement was considered low risk in nearly all studies.
The current meta-analysis highlighted that creatine supplementation produced a significant pooled effect on squat 1RM, while no significant effect was observed for leg press 1RM. Jump height showed a small but statistically significant improvement overall, though results varied widely across studies and should be interpreted with caution due to substantial heterogeneity.
Anaerobic power also improved, with significant gains in both peak and mean Wingate power. Creatine also increased fat-free mass by 2.32 kg and lean body mass by 1.61 kg, with these pooled effects largely driven by studies conducted in resistance training settings.
Subgroup analyses by training modality revealed significant squat 1RM improvements in both RT and non-RT contexts, with a statistically significant between-subgroup difference indicating a larger effect in non-RT settings; however, this finding is based on a limited number of studies and may reflect baseline differences or learning effects rather than a true superiority of non-RT contexts.
Jump height improvements were not statistically significant in RT studies and were significant only in non-RT studies, with no significant between-subgroup difference observed. Wingate peak and mean power improved significantly in both RT and non-RT settings, with no meaningful difference between them.
Body composition gains were confined to RT settings, where both FFM and LBM increased significantly in RT studies and not in non-RT studies. Jump height gains were significant only in trials lasting 8 weeks or more, with a gain of 8.06 cm; however, this estimate is based on a small number of studies and should be interpreted cautiously, suggesting that benefits accumulate with longer supplementation.
Stratified by competition level, jump improvements of 3.55 cm were significant in competitive athletes but not in recreational participants. Daily supplementation was associated with significant within-group improvements, though no clear difference was observed between daily and non-daily dosing strategies.
Sensitivity analyses confirmed that results were robust and not driven by any single study. Notably, no evidence of publication bias was detected across any outcome. Evidence certainty was high for Wingate peak power, moderate for squat strength and body composition outcomes, and low for leg press and jump height, due to inconsistent findings across studies.
Conclusions
Creatine’s effects in young healthy men were meaningfully shaped by training context. Lean mass outcomes improved only when creatine was combined with RT, supporting the view that creatine acts as a training amplifier rather than an independent driver of muscle accretion. Anaerobic power, by contrast, increased regardless of training status. Strength outcomes were specific, with improvements observed in squat strength but not in leg press performance.
Overall, these findings highlight the importance of considering training context when interpreting creatine’s benefits and support combining it with resistance training when lean mass gain is the primary goal. It should also be noted that short-term increases in lean mass may partly reflect intracellular water retention rather than purely contractile tissue growth.
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