EXERCISE-INDUCED HORMONAL RESPONSES TO HMB ADMINISTRATION: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

ABSTRACT Introduction: The β-hydroxy β-methyl butyrate (HMB) is an amino acid leucine metabolite with several ergogenic benefits. It is known that it can benefit testosterone and cortisol concentration in athletes. However, no systematic review and meta-analysis has focused on the effects of HMB supplementation on testosterone and cortisol in trained athletes. Objectives: The meta-analysis evaluates the effect of HMB supplementation on testosterone and cortisol in trained athletes and verifies conflicting results between studies. Methods: A systemic review was performed in Scopus, Medline, and Google scholar databases of articles published until August 2021. The Cochrane Collaboration tool was used to assess the risk of bias and assess the quality of the studies. Random effects model, weighted mean difference (WMD), and 95% confidence interval (CI) were used to estimate the overall effect. Results: Although the meta-analysis showed that HMB consumption does not alter cortisol and testosterone concentration, subgroup analysis based on exercise type exhibited a significant decrease in cortisol concentration in resistance training exercises (P<0.05) and a significant increase in testosterone concentration in combined aerobic and anaerobic sports (P<0.05). Conclusion: The results indicate that HMB supplementation in athletes can reduce cortisol concentration in endurance exercise and increase testosterone concentration in combined aerobic and anaerobic exercise. Evidence Level II; Therapeutic Studies – Investigating the results.