Abstract
Creatine monohydrate (CrM) and -hydroxy -methylbutyrate (HMB) are widely studied ergogenic aids. However, both supplements are usually studied in an isolated manner. The few studies that have investigated the e ect of combining both supplements on exercise-induced muscle damage (EIMD) and hormone status have reported controversial results. Therefore, the main purpose of this study was to determine the e ect and degree of potentiation of 10 weeks of CrM plus HMB supplementation on EIMD and anabolic/catabolic hormones. This study was a double-blind, placebo-controlled trial where participants (n=28) were randomized into four di erent groups: placebo group (PLG;n=7), CrM group (CrMG; 0.04 g/kg/day of CrM;n=7), HMB group (HMBG; 3 g/day of HMB;n=7), and CrM-HMB group (CrM-HMBG; 0.04 g/kg/day of CrM plus 3 g/day of HMB;n=7). Before (baseline, T1) and after 10 weeks of supplementation (T2), blood samples were collected from all rowers. There were no signi cant di erences in the EIMD markers (aspartate aminotransferase, lactate dehydrogenase, and creatine kinase) among groups. However, we observed signi cant di erences in CrM-HMBG with respect to PLG, CrMG, and HMBG on testosterone (p=0.006; 2 p=0.454) and the testosterone/cortisol ratio (T/C;p=0.032; 2p=0.349). Moreover, we found a synergistic e ect of combined supplementation on testosterone (CrM-HMBG= 63.85% vs. CrMG+HMBG= 37.89%) and T/C (CrM-HMBG=680% vs. CrMG+HMBG=57.68%) and an antagonistic e ect on cortisol (CrM-HMBG=131.55% vs. CrMG+HMBG=389.99%). In summary, the combination of CrM plus HMB showed an increase in testosterone and T/C compared with the other groups after 10 weeks of supplementation. Moreover, this combination presented a synergistic e ect on testosterone and T/C and an antagonistic e ect on cortisol compared with the sum of individual or isolated supplementation.
Description
This study investigates the effects of CrM and HMB supplementation on muscle damage and hormone levels in elite rowers.