A popular recipe for building lean body mass is resistance training plus whey protein. But an often overlooked part of this equation is muscle recovery, which, when ignored, can stifle progress. Fortunately, research has found that whey protein fortified with calcium beta-hydroxy-beta-methylbutyrate (HMB) and isomaltulose may aid muscle recovery time. HMB is produced when the body breaks down leucine (an amino acid) and has been found to promote muscle growth when combined with exercise. Isomaltulose is a slow-release carbohydrate thought to prevent fatigue in athletes. The double-blind study, published in the Journal of the American College of Nutrition, included 13 men, aged 18 to 26, who were already engaged in resistance training. The men received either a whey protein supplement or a whey protein supplement fortified with HMB and isomaltulose, twice daily for 19 days. After two weeks of supplementation, the men participated in an intense resistance training routine for three consecutive days. The routine included heavy resistance training on day one and metabolic resistance training (a workout with little rest in between each exercise to increase ones metabolic rate) on days two and three; the men then rested for the next two days (days four and five). Researchers tested for markers of muscle damage, muscle soreness, and multi-directional jump performance throughout the study. They found that, when compared with men taking the unfortified supplement, men taking the fortified supplement had:

• lower levels of markers for muscle damage on days four and five,
• less muscle-soreness on day four, and,
• higher vertical jump power on days four and five.

The study’s findings suggest that the fortified whey protein formula may be beneficial for weight lifters performing intense resistance training. Some previous research also supports HMB’s role in promoting muscle mass in people at risk for muscle loss (such as those confined to bed rest). 

Source: Journal of the American College of Nutrition