Effects of β-Hydroxy-β-methylbutyrate-free Acid Supplementation on Strength, Power and Hormonal Adaptations Following Resistance Training

Abstract

Background: β-Hydroxy-β-methylbutyrate-free acid (HMB-FA) has been ingested prior to exercise to reduce muscle damage, however the effects of HMB-FA supplementation on hormonal, strength and power adaptation are unclear. Methods: Sixteen healthy men were matched and randomized into two groups and performed six-week resistance training while supplementing with either HMB-FA or placebo (3 g per day). The subjects were evaluated for 1 repetition maximum (1RM) bench press and leg press and vertical jump (VJ) prior to and after training intervention. In addition, blood samples were obtained before and after resistance training to evaluate resting growth hormone (GH), insulin like growth factor 1 (IGF-1), testosterone (TEST), cortisol (CORT), and adrenocorticotropic hormone (ACTH) responses. The HMB-FA supplementation group showed greater gains compared with the placebo group in peak power (effect size ES = 0.26 vs. 0.01) and 1RM leg press (ES = 1.52 vs. 0.96). In addition, the HMB-FA supplementation group indicated greater decrements in ACTH and CORT responses to training in comparison to the placebo group (p < 0.05). Likewise, in GH (ES = 1.41 vs. 0.12) and IGF-1 (ES = 0.83 vs. 0.41), the HMB-FA indicated greater training effects when compared with the placebo group. Conclusions: These findings provide further support for the potential anabolic benefits associated with HMB-FA supplementation.

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

“…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].…”

“…There is also evidence that HMB regulates adipose tissue function including fatty acid oxidation, lipolysis, and adipokine secretion, which may be mediated by mTOR and p-AMP-activated protein kinase α (AMPKα) [2]. Combined HMB-supplementation and resistance training has been reported to positively affect health and physical performance by increasing the fat free mass (FFM) and decreasing fat mass (FM), reducing muscle soreness and improving strength in both previously untrained and trained individuals [3][4][5][6][7][8]. Increased FFM has also been shown to increase metabolic rate [9], maximal oxygen uptake, and ventilatory thresholds [10,11].…”

Long-Term Effect of Combination of Creatine Monohydrate Plus β-Hydroxy β-Methylbutyrate (HMB) on Exercise-Induced Muscle Damage and Anabolic/Catabolic Hormones in Elite Male Endurance Athletes

“…Likewise, CrM can enhance skeletal muscle glycogen storage [27,28], although the main reason for this increase is unclear [27]. On the other hand, HMB has presented decreases in CK [29][30][31][32], LDH [31], and cortisol [32][33][34] levels and increases in testosterone [35]. The pathway by which HMB could influence the delay of fatigue could be through an enhancement of glycogen synthesis [36] by the inhibition of glycogen synthase kinase-3 (GSK3), which negatively regulates glycogen synthesis [37].…”

Effects of Leucine Metabolite (&Beta;-Hydroxy-&Beta;-Methylbutyrate) Supplementation and Resistance Training on Cardiovascular Risk Factors, Oxidative Stress, and Inflammatory Markers: a Review on Recent Literature

“…Normal plasma range of HMB concentrations is 1 to 4 µmol/L, but can increase 5-to 10-fold following leucine administration [32]. Although some foods including citrus fruits, some fish, and breast milk have a mount of HMB [29], it is impractical to provide the typical 3 g daily dosage of HMB used in most previous human studies that demonstrate improvement of body composition [5,6,[8][9][10], and muscle strength [5,[8][9][10][11][12]. Therefore, HMB supplementation is a reasonable way for different athletes, specifically, those who participate in resistance training programs to obviate the recommended daily amount of HMB.…”

“…HMB is added to many training protocols with hopes of enhanced lean muscle mass and sports performance [4]. Scientific researches during the past 20 years demonstrate that HMB supplementation in conjunction with resistance training may improve body composition [5][6][7][8][9][10], muscle strength [5,[7][8][9][10][11][12] and power [5,8,11]. It has also been reported that supplying HMB promotes favorable changes in aerobic [13][14][15] and anaerobic [9,13,16] capacity, and muscle recovery after exercise [10,[17][18][19][20] in different athletes.…”