Effects of beta-hydroxy-beta-methylbutyrate supplementation on physical performance of young players during an intensified soccer-training period: A short report

Purpose. The objective of the study was to assess the effects of a 4-week intensified period of in-season soccer training with addition of explosive training and beta-hydroxy-beta-methylbutyrate (HMB) supplementation on maximal-intensity and endurance performance in young male soccer players, compared with a parallel training with placebo (i.e. Magnesium stearate) supplementation. Methods. A randomized, double-blind, placebo-controlled trial was conducted. Male athletes (age, 18.6 ± 1.4 years) were assigned either to a group receiving HMB supplementation (n = 9) or to a placebo group (n = 7). Results. The athletes were evaluated for maximal-intensity jumping and endurance performance before and after the intervention. Before the intervention, the two groups were characterized by similar age, body mass, height, and soccer experience. In addition, no differences between groups were observed for physical performance measures other than a greater countermovement jump performance in the HMB group compared with the placebo group. After the intervention, neither group showed any significant change in any of the physical performance measures. Conclusions. Compared with a 4-week intensified period of in-season soccer training with addition of explosive training and placebo supplementation, HMB supplementation did not add further adaptive changes related to maximal-intensity and endurance performance in young male soccer players.