No effect of HMB or α‐HICA supplementation on training‐induced changes in body composition

Abstract

β-hydroxy-β-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxyisocaproic acid (α-HICA) are leucine metabolites that have been proposed to improve body composition and strength when combined with resistance exercise training (RET). In this double-blind randomized controlled pragmatic trial, we evaluated the effects of off-theshelf supplements: α-HICA, HMB-FA and HMB-Ca, on RET-induced changes in body composition and performance. Forty men were blocked randomized to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg) or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training protocol consisted of a whole-body resistance training routine, thrice weekly for 8 weeks. Body composition was assessed by dual-energy x-ray absorptiometry (DXA) and total body water (TBW) by whole-body bioimpedance spectroscopy (BIS), both at baseline and at the end of weeks 4 and 8. Time-dependent changes were observed for increase in trunk FFM (p < 0.05). No statistically significant between-group or group-by-time interactions were observed. Supplementation with HMB (FA and Ca) or α-HICA failed to enhance body composition to a greater extent than placebo. We do not recommend these leucine metabolites for improving body composition changes with RET in young adult resistance trained men.

Effects of Nutritional Supplements on Judo‐Related Performance: A Review

“…Therefore, the effect of HMB on protein synthesis seems to be restricted to some anti-catabolic stimuli by which HMB may blunt protein degradation through anti-apoptotic signaling via the ubiquitin-proteasome pathway ( Smith et al, 2004 ), promoting myogenic proliferation, differentiation and survival ( Kornasio et al, 2009 ). Considering the controversy about the anabolic role of HMB ( Teixeira et al, 2018 ), its anti-catabolic effect seems to be out of debate.…”

Nutritional Strategies to Offset Disuse-Induced Skeletal Muscle Atrophy and Anabolic Resistance in Older Adults: From Whole-Foods to Isolated Ingredients

“…Specifically, one study observed significant improvements in body composition and muscle strength, which were associated with a~20% reduction in MPB (assessed via urinary 3-Methylhistidine excretion) and reductions of indirect markers of muscle damage (i.e., creatine kinase and lactate dehydrogenase) [155]. However, more recent RCTs [156][157][158][159] and meta-analyses [160,161] have failed to detect any benefit (i.e., increases in muscle mass, strength or function) of HMB in trained [162] or clinical populations [161]. Nevertheless, HMB is still considered a nutritional compound that may possess the potential to attenuate the rate muscle loss during ageing and disuse [160,[163][164][165][166].…”

Supplementation with the Leucine Metabolite β-hydroxy-β-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-Analysis

“…Two additional studies were excluded (Table S2) after visual funnel plots symmetry analysis ( Figure S1A) [35,36]. No asymmetry was detected when considering the remaining studies [2,[4][5][6][8][9][10]12,[37][38][39] (Figure S1B). One study received high risk of bias classification in three domains (selection bias, performance bias and other bias) [2].…”

“…β-hydroxy-β-methylbutyrate (HMB) is a metabolite derived from the essential amino acid leucine [1]. Some research suggests that HMB is an anabolic compound that increases resistance exercise training-(RET)-induced gains in fat-free mass (FFM) [2][3][4][5][6][7][8][9]. Also, many studies have been conducted to examine the impact of HMB on body fat loss and muscle strength and performance-related outcomes [7,[10][11][12].…”