
Calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation has been reported to reduce muscle catabolism and promote gains in fat-free mass and strength in subjects initiating training. However, whether HMB supplementation promotes these adaptations in trained athletes is less clear. This study examined the effects of HMB (as the calcium salt) supplementation during resistance training (6.9+/-0.7 hr x wk(-1)) on markers of catabolism, body composition and strength in experienced resistance-trained males. In a double-blind and randomized manner, 40 experienced resistance-trained athletes were matched and assigned to supplement their diet for 28 d with a fortified carbohydrate/protein powder containing either 0, 3 or 6 g x d(-1) of calcium HMB. Fasting venous blood and urine samples, dual energy X-ray absorptiometer-determined body composition, and isotonic bench press and leg press one repetition maximums (1 RM) were determined prior to and following 28 d of supplementation. HMB supplementation resulted in significant increases in serum and urinary HMB concentrations. However, no statistically significant differences were observed in general markers of whole body anabolic/catabolic status, muscle and liver enzyme efflux, fat/bone-free mass, fat mass, percent body fat, or 1 RM strength. Results indicate that 28 d of HMB supplementation (3 to 6 g x d(-1)) during resistance-training does not reduce catabolism or affect training-induced changes in body composition and strength in experienced resistance-trained males. (1)
PMID: 10606212 [PubMed - indexed for MEDLINE]
Effects of calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation during resistance-training on markers of catabolism, body composition and strength. ; Kreider RB, Ferreira M, Wilson M, Almada AL. ; Department of Human Movement Sciences & Education, The University of Memphis, TN 38152, USA. [link widoczny dla zalogowanych Użytkowników]
Ad1. Podsumowanie
W tym przypadku badany był wpływ 28-dniowej suplementacji HMB/placebo (0g; 3g; 6g HMB/d) na sportowców, pod kątem hamowania/powstrzymywania katabolizmu, wpływu na wzrost beztłuszczowej masy ciała, oraz siły/wytrzymałości w wybranych ćwiczeniach.
Nie zanotowano pozytwywnego wpływu HMB na zdolności wysiłkowe/skład ciała/hamowanie katabolizmu na grupię osób wytrenowanych stosujących HMB.
This investigation evaluated the effects of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation on training responses in resistance-trained male athletes who were randomly administered HMB in standard encapsulation (SH), HMB in time release capsule (TRH), or placebo (P) in a double-blind fashion. Subjects ingested 3 g x day(-1) of HMB or placebo for 6 weeks. Tests were conducted pre-supplementation and following 3 and 6 weeks of supplementation. The testing battery assessed body mass, body composition (using dual energy x-ray absorptiometry), and 3-repetition maximum isoinertial strength, plus biochemical parameters, including markers of muscle damage and muscle protein turnover. While the training and dietary intervention of the investigation resulted in significant strength gains (p < .001) and an increase in total lean mass (p = .01), HMB administration had no influence on these variables. Likewise, biochemical markers of muscle protein turnover and muscle damage were also unaffected by HMB supplementation. The data indicate that 6 weeks of HMB supplementation in either SH or TRH form does not influence changes in strength and body composition in response to resistance training in strength-trained athletes.(2)
PMID: 11599506 [PubMed - indexed for MEDLINE]
Beta-hydroxy-beta-methylbutyrate (HMB) supplementation does not affect changes in strength or body composition during resistance training in trained men. ; Slater G, Jenkins D, Logan P, Lee H, Vukovich M, Rathmacher JA, Hahn AG ; Sports Medicine Sports Science Division of the Singapore Sports Council, National Stadium, Singapore.
Ad2. Podsumowanie
Badano tutaj wpływ HMB na wytrenowanych sportowców, którym podawano zależnie od grupy: 3g HMB w kapsułkach standardowych/ 3g HMB w kapsułkach o przedłużonym wchłanianiu/ placebo.Test wykonany został metodą podwójnej ślepej próby i przeprowadzony był pod kątem wpływu w/w substancji na skład ciała i siłę zawodników.
Nie zanotowano wpływu HMB (niezależnie od formy podania, czy to w standardowej otoczce, czy w kapsułce o przedłużonym uwalnianiu) na skład ciała i siłę zawodników.
This study assesses the effects of daily beta-hydroxy beta-methylbutyrate (HMB) supplementation on muscular strength (bench press, squats, and power cleans) and body composition (body weight and body fat) among collegiate football players undergoing a strenuous exercise program. Subjects were collegiate football players (n = 35) training under the supervision of certified strength coaches averaging 20 hours of weekly exercise. In the first supplementation period, 16 of the 35 subjects were supplemented with 3 g of HMB per day for 4 weeks; the other 19 received a placebo followed by a 1-week washout period and then a second supplementation period in a randomized double-blind crossover, placebo design. There were no significant changes (p > 0.05) in muscular strength, including bench press, squats, and power cleans, among the subjects. There were also no significant changes (p > 0.05) in body composition, including body fat and body weight. Very little clinical evidence exists for supplementing HMB in athletic populations.
he effect of beta-hydroxy beta-methylbutyrate on muscular strength and body composition in collegiate football players. ; Ransone,-J; Neighbors,-K; Lefavi,-R; Chromiak,-J; ; J-Strength-Cond-Res. 2003 Feb; 17(1): 34-9
Ad3. Podsumowanie
Ostatnie juz badanie, sprawdzające jak poprzednie wpływ suplementacji HMB na siłę (wyciskanie na ławie, przysiad, zarzut) i skład ciała futbolistów (35 osob, 16 podawano placebo, 19 - HMB w dawce 3g/d) , poddanych 20 godzinom treningu na tydzień. Badanie trwało 4 tygodnie.
Nie zanotowano satysfakcjonujących różnic pomiędzy obiema grupami, tak w wynikach siłowch, jak i w różnicach dotyczących składu ciała.
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