Twenty-three trained men took either a single (3 g) dose of HMB free acid or a placebo 60 minutes before undergoing a single bout of high-intensity exercise. The exercise bout resulted in muscle swelling, decreased jump performance, and decreased force production in both groups, but the participants’ highly trained status allowed for a quick return to normal (within 24 h). However, the single dose of HMB free acid significantly improved recovery of work capacity; the men who took HMB recovered work capacity in just 24 hours, while the placebo group had not yet recovered at 72 hours. Thus, even a single dose of HMB free acid allowed the participants to recover to their full training capacity much sooner after a strenuous, high intensity training session.
Research By Year
Pre-exercise beta-hydroxy-beta-methylbutyrate free-acid supplementation improves work capacity recovery: a randomized, double-blinded, placebo-controlled study.
In a comprehensive review of HMB studies over the past two decades, the authors examine HMB efficacy. This review also examines why many newer studies, longer in length than some of the original studies and also conducted with HMB in the free acid form, are suggestive of stronger efficacy in both trained and untrained populations. The authors concluded that recent studies utilizing high-intensity training have demonstrated HMB efficacy in maintaining muscle mass and attenuating the inflammatory response. In particular these studies show improved efficacy of HMB free acid in trained athletes.
The Effect of β-Hydroxy-β-Methylbutyrate on Aerobic Capacity and Body Composition in Trained Athletes.
The effects of HMB supplementation in highly-trained combat sport athletes (wrestlers, judokas, and Brazilian jiu-jitsu) was studied. The athletes maintained their usual daily training and dietary regimens during the placebo-controlled crossover study. HMB supplementation resulted in an increase in lean body mass and decrease in fat mass compared with placebo supplementation. In addition HMB supplementation resulted in increased aerobic capacity and anaerobic peak power. The authors concluded that for combat sport athletes, HMB promotes advantageous changes in body composition and aerobic and anaerobic capacity.
Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism.
The authors studied muscle protein synthesis (MPS) and muscle protein breakdown (MPB) in young males supplemented with CaHMB. Similar to their previous study with HMB free acid, CaHMB provided a comparable stimulation of MPS and suppression of MPB. The pro-anabolic properties of CaHMB were shown to include activation of mTORc1. Therefore, both CaHMB and HMB free acid have similar effects on muscle protein turnover despite the differences reported in bioavailability.
Combined effect of Bacillus coagulans GBI-30, 6086 and HMB supplementation on muscle integrity and cytokine response during intense military training.
Soldiers undergoing intense military training were supplemented for 40 days with either a placebo, HMB, or HMB plus probiotic (Bacillus coagulans GBI-30). While HMB and HMB plus probiotic attenuated the inflammatory responses (IL-1β, IL-2, IL-6, CX3CL1, and TNF-α), HMB combined with the probiotic attenuated the inflammatory marker IL-10 and resulted in improved muscle integrity over HMB alone. Therefore combining the probiotic with HMB may be more effective in maintaining muscle integrity than HMB alone during intense military training.