Abstract
Creatine monohydrate (CrM) and β-hydroxy β-methylbutyrate (HMB) are widely studied ergogenic aids. However, both supplements are usually studied in an isolated manner. The few studies that have investigated the effect 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 effect 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 different 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 significant differences in the EIMD markers (aspartate aminotransferase, lactate dehydrogenase, and creatine kinase) among groups. However, we observed significant differences in CrM-HMBG with respect to PLG, CrMG, and HMBG on testosterone (p = 0.006; η2p = 0.454) and the testosterone/cortisol ratio (T/C; p = 0.032; η2p = 0.349). Moreover, we found a synergistic effect 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 effect 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 effect on testosterone and T/C and an antagonistic effect on cortisol compared with the sum of individual or isolated supplementation.
Highlights
Elite sports are immensely demanding at the physical and psychological level, and an adequate balance between training load and recovery is needed to achieve maximum performance [1]
The main result revealed an increase in testosterone and a better post-treatment testosterone/cortisol ratio (T/C) ratio in Creatine monohydrate (CrM)-HMB group (HMBG) compared with placebo group (PLG), CrM group (CrMG), and HMBG after 10 weeks of supplementation
The combination of CrM plus hydroxy β-methylbutyrate (HMB) presented a synergistic effect on testosterone and T/C and an antagonistic effect on cortisol compared with the sum of individual or isolated supplementation (CrM + HMB)
Summary
Elite sports are immensely demanding at the physical and psychological level, and an adequate balance between training load and recovery is needed to achieve maximum performance [1]. There are different markers to determine stress and fatigue levels due to the imbalance between training load and recovery, among which biochemical markers of exercise-induced muscle damage (EIMD) and anabolic/catabolic hormones are often used [5]. An increase in EIMD markers produced by sarcomeric degeneration from Z-disk fragmentation [6,7], such as creatine kinase (CK) and lactate dehydrogenase (LDH), may provide information about elevated muscular and/or metabolic stress [1,8]. LDH can increase until 3–5 days (up to two-fold rest values) [6] depending on different types of exercise/sport [6]. Despite the increase in EIMD being dependent on the training level of athletes, the intensity and duration of the exercise and the density and type of sport are important [6]. Eccentric and impact activities produce more significant EIMD than concentric and nonimpact activities [6]
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