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1.
β-hydroxy-β-methylbutyrate free acid supplementation may improve recovery and muscle adaptations after resistance training: a systematic review.
Silva, VR, Belozo, FL, Micheletti, TO, Conrado, M, Stout, JR, Pimentel, GD, Gonzalez, AM
Nutrition research (New York, N.Y.). 2017;:1-9
Abstract
β-Hydroxy-β-methylbutyrate free acid (HMB-FA) has been suggested to accelerate the regenerative capacity of skeletal muscle after high-intensity exercise and attenuate markers of skeletal muscle damage. Herein a systematic review on the use of HMB-FA supplementation as an ergogenic aid to improve measures of muscle recovery, performance, and hypertrophy after resistance training was conducted. This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We included randomized, double-blinded, placebo-controlled trials investigating the effects of HMB-FA supplementation in conjunction with resistance exercise in humans. The search was conducted using Medline and Google Scholar databases for the terms beta-hydroxy-beta-methylbutyrate, HMB free acid, exercise, resistance exercise, strength training, and HMB supplementation. Only research articles published from 1996 to 2016 in English language were considered for the analysis. Nine studies met the criteria for inclusion in the analyses. Most studies included resistance-trained men, and the primary intervention strategy involved administration of 3g of HMB-FA per day. In conjunction with resistance training, HMB-FA supplementation may attenuate markers of muscle damage, augment acute immune and endocrine responses, and enhance training-induced muscle mass and strength. HMB-FA supplementation may also improve markers of aerobic fitness when combined with high-intensity interval training. Nevertheless, more studies are needed to determine the overall efficacy of HMB-FA supplementation as an ergogenic aid.
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2.
β-Hydroxy-β-methylbutyrate attenuates cytokine response during sustained military training.
Hoffman, JR, Gepner, Y, Stout, JR, Hoffman, MW, Ben-Dov, D, Funk, S, Daimont, I, Jajtner, AR, Townsend, JR, Church, DD, et al
Nutrition research (New York, N.Y.). 2016;(6):553-63
Abstract
This study tested the hypothesis that of 23 days of β-hydroxy-β-methylbutyrate (HMB) supplementation can maintain muscle mass and attenuate the immune and inflammatory response in combat soldiers during highly intense military training. Soldiers were randomly assigned to either a HMB (n = 6) or placebo (PL; n = 7) group and provided with 3 g · day(-1) of either HMB or PL. During the final week of supplementation soldiers participated in extreme physical training, which included night navigation of 6-8 hours across difficult terrain carrying heavy loads combined with sleep deprivation (3.8 ± 3.0 h per night). Blood draws were performed prior to and following the supplementation period. Magnetic resonance imaging, which included diffusion tensor imaging sequence, was used for muscle fiber tracking analysis. Data was analyzed using a two-way mixed factorial analysis of variance. Magnitude-based inferences were used to provide inferences on the true effects that HMB may have had on the dependent variables compared to PL, calculated from 90% confidence intervals. Changes in tumor necrosis factor-α for HMB (-3.9 ± 8.2 pg · mL(-1)) were significantly lower (P = .043) compared to the change in PL (+4.0 ± 3.7 pg · mL(-1)). HMB ingestion was also very likely (92%-95% Likelihood) to lower granulocyte colony-stimulating factor and interleukin 10 compared to PL. In addition, HMB supplementation was likely (78%-87% likelihood) to reduce interferon-γ, interleukin 8, CX3CL1, and increase muscle volume for the adductor magnus (77% likelihood) compared to PL. In summary, the results of this study provides evidence that HMB supplementation may attenuate the inflammatory response to high intense military training, and maintain muscle quality.
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3.
Effects of β-hydroxy-β-methylbutyrate free acid and cold water immersion on expression of CR3 and MIP-1β following resistance exercise.
Gonzalez, AM, Fragala, MS, Jajtner, AR, Townsend, JR, Wells, AJ, Beyer, KS, Boone, CH, Pruna, GJ, Mangine, GT, Bohner, JD, et al
American journal of physiology. Regulatory, integrative and comparative physiology. 2014;(7):R483-9
Abstract
The inflammatory response to muscle-damaging exercise requires monocyte mobilization and adhesion. Complement receptor type 3 (CR3) and macrophage inflammatory protein (MIP)-1β enables monocyte recruitment, adhesion, and subsequent infiltration into damaged muscle tissue. The purpose of this study was to examine the effects of cold water immersion (CWI) and/or β-hydroxy-β-methylbutyrate free acid (HMB-FA) on CR3 expression and MIP-1β concentration after four sets of up to 10 repetitions of squat, dead lift, and split squat exercises at 70-80% 1-repetition maximum. Thirty-nine resistance-trained men (22.2 ± 2.5 yr) were randomly divided into four groups: 1) placebo (PL), 2) HMB-FA, 3) HMB-FA-CWI, and 4) PL-CWI. The HMB-FA groups ingested 3 g/day, and CWI groups were submersed into 10-12°C water for 10 min after exercise. Blood was sampled at baseline (PRE), immediately post- (IP), 30 min post- (30P), 24 h post- (24P), and 48 h post (48P)-exercise. Circulating MIP-1β was assayed and CR3 expression on CD14+ monocytes was measured by flow cytometry. Without treatment, CR3 expression significantly elevated at 30P compared with other time points (P = 0.030-0.047). HMB-FA significantly elevated the percentage of monocytes expressing CR3 between IP and 24P (P = 0.046) and between IP and 48P (P = 0.046). No time effect was observed for MIP-1β concentration. The recovery modalities showed to attenuate the rise in CR3 following exercise. Additionally, supplementation with HMB-FA significantly elevated the percentage of monocytes expressing CR3 during recovery. Although the time course that inflammatory responses are most beneficial remains to be determined, recovery modalities may alter immune cell mobilization and adhesion mechanisms during tissue recovery.
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4.
β-Hydroxy-β-methylbutyrate (HMB)-free acid attenuates circulating TNF-α and TNFR1 expression postresistance exercise.
Townsend, JR, Fragala, MS, Jajtner, AR, Gonzalez, AM, Wells, AJ, Mangine, GT, Robinson, EH, McCormack, WP, Beyer, KS, Pruna, GJ, et al
Journal of applied physiology (Bethesda, Md. : 1985). 2013;(8):1173-82
Abstract
The purpose of this study was to examine the effect of β-hydroxy-β-methylbutyrate-free acid (HMB-FA) and cold-water immersion (CWI) on circulating concentrations of TNF-α and monocyte TNF-α receptor 1 (TNFR1) expression. Forty resistance-trained men (22.3 ± 2.4 yr) were randomized into four groups [placebo (PL), HMB-FA, CWI, and HMB-FA-CWI] and performed an acute, intense exercise protocol (four sets of up to 10 repetitions of the squat, dead lift, and split squat). Participants also performed four sets of up to 10 repetitions of the squat at 24 and 48 h following the initial exercise bout. Blood was sampled before exercise (PRE), immediately postexercise (IP), and 30 min, 24 h, and 48 h postexercise (30P, 24P, and 48P, respectively). Circulating TNF-α was assayed, and TNFR1 expression on CD14+ monocytes was measured by flow cytometry. The exercise protocol significantly elevated TNF-α in only PL (P = 0.006) and CWI (P = 0.045) IP. Mean percent changes show that TNF-α significantly increased from PRE to IP for only PL and CWI groups (P < 0.05), whereas the percent change of TNF-α for HMB-FA and HMB-FA-CWI was not significant. TNFR1 expression was elevated in PL (P = 0.023) and CWI (P = 0.02) at 30P compared with PRE, whereas both HMB-FA-treated groups did not increase significantly. In conclusion, HMB-FA attenuated circulating TNF-α IP and TNFR1 expression during recovery compared with PL and CWI. HMB-FA supplementation may attenuate the initial immune response to intense exercise, which may reduce recovery time following intense exercise.
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5.
Beta-hydroxy-beta-methylbutyrate ingestion, part II: effects on hematology, hepatic and renal function.
Gallagher, PM, Carrithers, JA, Godard, MP, Schulze, KE, Trappe, SW
Medicine and science in sports and exercise. 2000;(12):2116-9
Abstract
PURPOSE The purpose of this investigation was to examine the effects of differing amounts of beta-hydroxy-beta-methylbutyrate (HMB), 0, 36, and 76 mg x kg(-1) x d(-1), on hematology, hepatic and renal function during 8 wk of resistance training. METHODS Thirty-seven, untrained collegiate males and were randomly assigned to one of the three groups, 0, 38, or 76 mg x kg(-1) x d(-1). Resistance training consisted of 10 exercises, performed 3 d x wk(-1) for 8 wk at 80% of their 1-repetition maximum. Blood and urine was obtained before training, 48 h after the initial session, 1 wk, 2 wk, 4 wk, and at 8 wk of resistance training. Blood was analyzed for glucose, blood urea nitrogen, hemoglobin, hepatic enzymes, lipid profile, total leukocytes, and individual leukocytes. Urine was analyzed for pH, glucose, and protein excretion. RESULTS The 38 mg x kg(-1) x d(-1) group had a greater increase in basophils compared with 0 or 76 mg x kg(-1) x d(-1) groups (P < 0.05). No difference occurred in any other blood and urine measurements. CONCLUSION These data indicate that 8 wk of HMB supplementation (< or = 76 mg x kg(-1) x d(-1)) during resistance training had no adverse affects on hepatic enzyme function, lipid profile, renal function, or the immune system.
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6.
Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study.
Clark, RH, Feleke, G, Din, M, Yasmin, T, Singh, G, Khan, FA, Rathmacher, JA
JPEN. Journal of parenteral and enteral nutrition. 2000;(3):133-9
Abstract
BACKGROUND The current study was designed to examine whether a combination of three nutrients, consisting of beta-hydroxy-beta-methylbutyrate (HMB), a metabolite of leucine, L-glutamine (Gln) and L-arginine (Arg), each of which has been previously shown to slow muscle proteolysis, could synergistically alter the course of muscle wasting in patients with established acquired immunodeficiency syndrome (AIDS). METHODS Sixty-eight human immunodeficiency virus (HIV)-infected patients with a documented weight loss of at least 5% in the previous 3 months were recruited from the HIV clinic at Nassau County Medical Center. The subjects were randomly assigned in a double-blind fashion to receive either placebo containing maltodextrin or the nutrient mixture (HMB/Arg/Gln) containing 3 g HMB, 14 g L-glutamine, and 14 g L-arginine given in two divided doses daily for 8 weeks. Body weights (BW) were recorded weekly and lean body mass (LBM) and fat mass (FM) were measured by air displacement plethysmography and by a single computerized tomography (CT) slice through the thigh at 0, 4, and 8 weeks. RESULTS Forty-three subjects completed the 8-week protocol, (placebo, n = 21; HMB/Arg/Gln, n = 22). At 8 weeks, the subjects consuming the HMB/Arg/Gln mixture gained 3.0 +/- 0.5 kg of BW while those supplemented with the placebo gained 0.37 +/- 0.84 kg (p = .009). The BW gain in the HMB/Arg/Gln-treated subjects was predominantly LBM (2.55 +/- 0.75 kg) compared with the placebo-supplemented subjects who lost lean mass (-0.70 +/- 0.69 kg, p = .003). No significant change in FM gain was observed (0.43 +/- 0.83 kg for the group receiving HMB/Arg/Gln and 1.07 +/- 0.64 kg for the group receiving the placebo, p > .20). Similar percentage changes in muscle mass and fat mass were observed with CT scans. Immune status was also improved as evident by an increase in CD3 and CD8 cells and a decrease in the HIV viral load with HMB/Arg/Gln supplementation. CONCLUSIONS The data indicate that the HMB/Arg/Gln mixture can markedly alter the course of lean tissue loss in patients with AIDS-associated wasting.