Several studies have suggested that Hydroxy-Methylbutyrate (HMB) may improve lean body mass, strength, and lipid oxidation when combined with a resistance training program. Additionally, HMB has been demonstrated to reduce proteolysis (protein degradation) and acute damage to muscle structures as a result of eccentric running. As a whole, very few studies have looked at the effects of HMB supplementation on aerobic training adaptations. Recently, researchers from the University of Sherbrooke examined the effects of five weeks of HMB supplementation coupled with a three times a week interval training regime. The interval training program consisted of five intervals performed at the individual’s maximal velocity for 50% of the time to exhaustion for that velocity. Recovery between each interval was performed at 60% of maximal. Each interval and its corresponding recovery summed to 100% of the time to exhaustion. Each session contained a five minute warm-up and recovery performed at 50% of the individual’s maximal running velocity. Supplementation consisted of the consumption of three grams per day over the five weeks. Results of this investigation revealed that the combination of interval training and HMB supplementation resulted in significantly greater increases in maximal oxygen consumption. There were no differences in body composition changes between groups. Based upon these results it was concluded that the addition of an HMB supplement to an interval training program results in significant improvements to selected components of aerobic performance.
Lamboley CR, Royer D, Dionne IJ. (2007). Effects of beta-hydroxy-beta-methylbutyrate on aerobic-performance components and body composition in college students. International Journal of Sport Nutrition and Exercise Metabolism, 17:56 — 69.