This study used a model cell culture system that represents what happens in an animal or human. Glucocorticoids, such as dexamethasone used in this study, cause increased muscle protein degradation and decreased protein synthesis, which result in a loss of muscle. HMB attenuated the negative effects of dexamethasone on protein degradation and protein synthesis and thus prevented the muscle loss.
Research By Year
Research By Year
In a study using sedentary rats of multiple age groups, from young to old, HMB supplementation was shown to maintain muscle mass as the rats aged. HMB simultaneously decreased fat mass in older rats. Thus, HMB supplementation may be useful in blunting the effects of sarcopenia (muscle loss with aging) in humans, even without a stimulus such as regular exercise.
Metabolic and functional effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation in skeletal muscle.
In this study utilizing rats, HMB was shown to improve muscle tetonic force after 4 weeks of oral supplementation. HMB also decreased muscle fatigue as measured by muscle tension developed over successive contractions. Additionally, HMB increased glycogen, ATP, and citrate synthase activity in these muscles, which may have been why the HMB-supplemented rats had increased tetonic force and fatigue resistance.
The effects of beta-hydoxy-beta-methylbutyrate free acid supplementation on muscle damage, hormonal status, and performance following a high volume 2-week overreaching cycle
The overreaching cycle during a resistance-training program is designed to simulate muscle stress that is encountered during higher intensity training, peaking for competition, or multiple-game tournaments. In this study, trained athletes underwent a 2-week overreaching cycle after 8 weeks of intense resistance-training. HMB free acid supplementation resulted in decreased CPK, an indicator of muscle damage; decreased cortisol, a stress hormone; and maintained more strength throughout the overreaching cycle. In conclusion HMB free acid provided more muscle protection against the sudden increase in training intensity compared to the placebo.
Effects of 12 weeks of beta-hydroxy-beta- methylbutyrate free acid gel supplementation on muscle mass, strength, and power in resistance trained individuals
This is the first 12-week study using the new delivery form of beta-hydroxy-beta-methylbutyrate, HMB free acid. Highly trained athletes underwent an intense, high-volume, resistance-training program, including a 2-week overreaching phase during weeks 9 and 10. HMB free acid supplemented subjects had greater strength gains, increased Wingate power, and increased muscle thickness compared with the placebo-supplemented subjects. This study showed that even in highly trained athletes, HMB free acid results in greater training gains over a 12-week periodized resistance-training program.
The acute effects of a free acid beta-hydoxy-beta- methyl butyrate supplement on muscle damage following resistance training: a randomized, double-blind, placebo-controlled study
This is the first resistance training study to examine the acute effects of HMB free acid supplementation on muscle damage and perceived recovery scale (PRS) when initiating a high-volume resistance-training program. The results showed that when compared to placebo, HMB free acid resulted in decreased CPK indicating decreased muscle damage, and an increase in PRS meaning the subjects felt more recovered 48 hours after the training. In conclusion, HMB free acid minimized the initial muscle damage and improved recovery in trained athletes initiating a high-volume training program.