The Study
Does HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis
This study looked at lots of smaller studies about a supplement called HMB and whether it helps athletes build muscle. But none of the small studies were sure if they were done fairly—like if people were randomly assigned to take it or not. So we can't say HMB definitely helps; we can only say it might be linked to a tiny bit more muscle, but it's not clear.
Analysis score
Maximum 85 for a systematic review with meta-analysis.
Where the score came from
HMB is a supplement some athletes take to build muscle, but this study looked at all the research to see if it really works.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 539 / 100
Quality score
Systematic reviews and meta-analyses of cohort studies. They sit above a single cohort study but below a single randomized trial, because the underlying evidence is still observational.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The muscle gain is so small and uncertain that it likely doesn't matter much for real-world performance unless protein intake is very low.
- 2HMB slightly increased muscle mass by 0.30 kg on average, but it wasn't a big enough change to be sure it wasn't just luck.
- 3It didn't change total weight or fat at all.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Strength and Conditioning Research
Year
2019
Authors
Brett M. Holland, Brandon M. Roberts, J. Krieger, B. Schoenfeld
Related Content
Claims (5)
Taking HMB supplements does not significantly increase muscle growth in people who already eat enough protein, but might slightly affect muscle growth when calorie intake is very low or training intensity is extremely high.
HMB, a supplement used by athletes, may only help increase fat-free mass in those who eat less than 1.6 grams of protein per kilogram of body weight each day. For athletes consuming more protein, HMB does not appear to provide additional benefit.
Taking 3 grams of HMB daily for four weeks or longer may be linked to a very small increase in lean body mass in athletes, but this effect is not statistically significant and may only occur if protein intake is less than 1.6 grams per kilogram of body weight per day.
Taking HMB supplements does not lead to a meaningful change in total body weight for athletes, based on data from multiple studies.
Taking HMB supplements does not lead to a meaningful change in fat mass among athletes, based on data from multiple studies combining 128 participants.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.