Equivalent Hypertrophy and Strength Gains in β-Hydroxy-β-Methylbutyrate- or Leucine-supplemented Men

Abstract

HMB added to whey did not result in greater increases in any measure of muscle mass, strength, or hormonal concentration compared to leucine added to whey. Our results show that HMB is no more effective in stimulating RT-induced hypertrophy and strength gains than leucine.

Combined protein and calcium β-hydroxy-β-methylbutyrate induced gains in leg fat free mass: a double-blinded, placebo-controlled study

“…Kraemer et al [4], Wilson et al [8], and Lowery et al [6] observed gains of about 7 to 8 kg FFM in subjects supplemented with 3 g of HMB per day. Our results are more in line with data recently published by Jakubowski et al [20], who reported 2.3 kg and 2.6 kg gains in whole-body FFM after 12-weeks of resistance training with protein plus HMB (3 g per day) and protein plus leucine (3 g per day) supplementation, respectively. Such moderate increases in FFM are also supported by a recent meta-analysis, showing that with total protein intake of at least 1.6 g•kg − 1 •day − 1 training-induced gains in FFM can reach a maximum of about 4 kg with an average of about 1.5 kg [38].…”

“…The changes in 1-RM were in a typical range reported in previous 12-week resistance training studies for bench press [3,8,20] and leg press [3], but considerably lower than those reported by Kraemer et al [4] and Lowery et al [6]. Some of these studies reported no [20] or a slight effect [3] of HMB on 1-RM gains, whereas others found a strong effect [4,6,8]. Our findings were in line with a study by Gallagher et al [42] that examined the effects of HMB, administered in doses of 0 g, 3 g or 6 g per day on FFM and strength during eight weeks of resistance training in 37 untrained men [42].…”

“…Because segmental measurements for estimating FFM reflect more closely the underlying biophysical model of BIS to whole-body BIS (assumption of isotropic conductor with homogeneous cross-sectional area and consistent proportions specific tissues), we expected segmental measurements to be more accurate and precise than whole-body FFM estimations [27,28,31]. The methodological difference between single slice recordings and total limb estimations in tracking changes in segmental hypertrophy may also explain the lack of detecting an ergogenic effect associated with HMB supplementation in two very recent studies, employing similar study designs [20,22]. However, it should also be noted that the subjects in the present study were untrained men, whereas the aforementioned study were performed in resistance-trained men.…”

“…It is also possible that whole-body BIS might not have been accurate and precise enough to detect any differences in body composition between the groups. Whereas other studies also failed to detect changes in body composition using dual-energy x-ray absorptiometry (DXA) [20], future studies should consider more sophisticated techniques such as DXA, air displacement plethysmography, or magnetic resonance imaging to examine the effects of HMB on whole-body composition.…”

“…There is also increasing interest whether HMB supplementation can augment strength training-induced gains in FFM when a highprotein diet is provided [5,[20][21][22][23]. Recent studies suggest that protein balance is the critical driver for strength-training induced changes in muscle mass in resistance-trained men [20,22,23]. Accordingly, it has been questioned whether HMB supplementation can provide any additional benefits over and above regular protein intake on body composition and performance.…”