Sport Physiology & Management Investigations

Sport Physiology & Management Investigations

Acute Effect of Free Acid Beta-Hydroxy Beta-Methylbutyrate (HMB-FA) Supplementation on Testosterone, Cortisol, and Testosterone-to-Cortisol Ratio (T/C) Responses in Non-Athlete Men Following a Single Session of Resistance Exercise

Document Type : Original Article

Authors
Zeinab Jahan
Farhad Daryanoosh
Maryam Koushkie Jahromi
Department of Sports Science, Faculty of Education and Psychology, Shiraz University, Shiraz, Iran
10.22034/spmi.2026.568606.2832
Abstract
Supplementation with B-hydroxy-B-methylbutyrate in its free acid form (HMB-FA) has high potential to modulate hormonal responses due to its superior bioavailability. This study aimed to investigate the acute effect of HMB-FA supplementation on testosterone and cortisol responses, as well as the testosterone-to-cortisol (T/C) ratio, following a single session of resistance exercise in untrained men. In this double-blind, semi-experimental study, 20 untrained men were randomly assigned to either an experimental group (n=10) or a placebo group (n=10). Initially, fasting blood samples were collected to measure baseline levels. The experimental group then consumed 3 grams of HMB-FA, while the placebo group consumed an equivalent amount of stevia. After 30 minutes, a second blood sample was taken, followed by a resistance training protocol consisting of 7 exercises (at 70% of 1RM, in 3 sets of 8-10 repetitions). Final blood samples were collected immediately post-exercise. Data were analyzed using Mixed ANOVA and T-tests. The results indicated no significant differences between the two groups in testosterone and cortisol concentrations or the T/C ratio at any stage—before or after supplementation/placebo intake and post-exercise (P > 0.05). However, analysis of the acute trends showed a 24.5% increase in testosterone and a 24.5% decrease in cortisol in the supplementation group compared to the placebo group, although these changes were not statistically significant.
Keywords
Resistance Training
Anabolic-Catabolic Balance
Testosterone
Cortisol
HMB-FA Supplementation