Title

The Effects Of 12 Weeks Of Beta-Hydroxy-Beta-Methylbutyrate Free Acid Supplementation On Muscle Mass, Strength, And Power In Resistance-Trained Individuals: A Randomized, Double-Blind, Placebo-Controlled Study

Keywords

Leucine metabolite; Overreaching; Recovery; Resistance training; Sports supplements

Abstract

Introduction: Studies utilizing beta-hydroxy-beta-methylbutyrate (HMB) supplementation in trained populations are limited. No long-term studies utilizing HMB free acid (HMB-FA) have been conducted. Therefore, we investigated the effects of 12 weeks of HMB-FA supplementation on skeletal muscle hypertrophy, body composition, strength, and power in trained individuals. We also determined the effects of HMB-FA on muscle damage and performance during an overreaching cycle. Methods: A three-phase double-blind, placebo- and diet-controlled randomized intervention study was conducted. Phase 1 was an 8-week-periodized resistance-training program; Phase 2 was a 2-week overreaching cycle; and Phase 3 was a 2-week taper. Muscle mass, strength, and power were examined at weeks 0, 4, 8, and 12 to assess the chronic effects of HMB-FA; and assessment of these, as well as cortisol, testosterone, and creatine kinase (CK) was performed at weeks 9 and 10 of the overreaching cycle. Results: HMB-FA resulted in increased total strength (bench press, squat, and deadlift combined) over the 12-week training (77.1 ± 18.4 vs. 25.3 ± 22.0 kg, p < 0.001); a greater increase in vertical jump power (991 ± 168 vs. 630 ± 167 W, p < 0.001); and increased lean body mass gain (7.4 ± 4.2 vs. 2.1 ± 6.1 kg, p < 0.001) in HMB-FA- and placebo-supplemented groups, respectively. During the overreaching cycle, HMB-FA attenuated increases in CK (-6 ± 91 vs. 277 ± 229 IU/l, p < 0.001) and cortisol (-0.2 ± 2.9 vs. 4.5 ± 1.7 μg/dl, p < 0.003) in the HMB-FA- and placebo-supplemented groups, respectively. Conclusions: These results suggest that HMB-FA enhances hypertrophy, strength, and power following chronic resistance training, and prevents decrements in performance following the overreaching. © 2014 The Author(s).

Publication Date

1-1-2014

Publication Title

European Journal of Applied Physiology

Volume

114

Issue

6

Number of Pages

1217-1227

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1007/s00421-014-2854-5

Socpus ID

84901387272 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84901387272

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