Effect of β-hydroxy-β-methylbutyric acid on muscle protection during taekwondo team training

[Objective] To investigate the effect of <i>β</i>-hydroxy-<i>β</i>-methylbutyrate （HM<i>β</i>） supplementation on muscle protection in taekwondo players during training. [Methods] 18 male subjects above the second level of the Taekwondo special Team who voluntarily participated in the experiment were recruited and divided into experimental and control groups （9 each） according to the conditions. The experimental group consumed one sachet （25 g/bag, the amount of HM<i>β</i> added was 500 mg/bag） of HM<i>β</i>-added milk powder before and after training （with a break of more than 30 min） in the morning and afternoon from Monday to Saturday, while the control group consumed the same amount of commercially available regular milk powder. Blood samples were collected before and after the intervention and on Monday mornings to analyze the changes in biochemical indicators, and quantitative tests of Taekwondo-specific abilities were performed before and after the experiment. [Results] Compared with the control group, the experimental group did not see significant changes in the pro-inflammatory factor interleukin-6, plasma glutamine levels were significantly increased （<i>P</i><0.05）, and plasma glycine levels did not see a significant decrease after intervention; Myoglobin was significantly decreased in the experimental group after intervention （<i>P</i><0.05）, and serum levels of total cholesterol, triglyceride, and LDL cholesterol were significantly lower than those of the control group （<i>P</i><0.05）. The decrease of blood urea nitrogen was smaller than that of the control group; The number of 20-second in situ knee lifts and the number of 30-second tuck jumps in the experimental group were both improved and increased more than that of the control group. [Conclusion] HM<i>β</i> supplementation during training can exert protective functions by reducing inflammation, improving immune function, maintaining muscle membrane stability, increasing nitrogen stores, and strengthening muscle remodeling ability, improving muscle adaptability to training to ensure their competitive status.