Negligible Effects of ß-Hydroxy-ß-Methylbutyrate Free Acid and Calcium Salt on Strength and Hypertrophic Responses to Resistance Training: A Randomized, Placebo-Controlled Study.

This study evaluated the effects of ß-hydroxy-ß-methylbutyrate free acid (HMB-FA) and calcium salt (HMB-Ca) on strength, hypertrophy, and markers of muscle damage. In this randomized, double-blind, placebo-controlled study, 44 resistance-trained men (age: 26 ± 4 years; body mass: 84.9 ± 12.0 kg) consuming ≥1.7 g·kg-1·day-1 of protein received HMB-FA (3 g/day; n = 14), HMB-Ca (3 g/day; n = 15), or placebo (PL; cornstarch, 3 g/day; n = 15) for 12 weeks, while performing a periodized resistance training program. Before and after intervention, lean body mass (measured with dual X-ray absorptiometry), maximal dynamic strength (one-repetition maximum), knee extension maximal isometric strength (maximal voluntary isometric contraction [MVIC]), cross-sectional area (measured with ultrasound), and muscle soreness were assessed. MVIC was also measured 48 hr after the first and the last training sessions. All groups increased lean body mass (main time effect: p < .0001; HMB-FA: 1.8 ± 1.8 kg; HMB-Ca: 0.8 ± 1.4 kg; PL: 0.9 ± 1.4 kg), cross-sectional area (main time effect: p < .0001; HMB-FA: 6.6 ± 3.8%; HMB-Ca: 4.7 ± 4.4%; PL: 6.9 ± 3.8%), one-repetition maximum bench press (main time effect: p < .0001; HMB-FA: 14.8 ± 8.4 kg; HMB-Ca: 11.8 ± 7.4 kg; PL: 11.2 ± 6.6 kg), MVIC (main time effect: p < .0001; HMB-FA: 34.4 ± 39.3%; HMB-Ca: 32.3 ± 27.4%; PL: 17.7 ± 20.9%) after the intervention, but no differences between groups were shown. HMB-FA group showed greater leg press strength after the intervention than HMB-Ca and PL groups (Group × Time interaction: p < .05; HMB-FA: 47.7 ± 31.2 kg; HMB-Ca: 43.8 ± 31.7 kg; PL: 30.2 ± 20.9 kg). MVIC measured 48 hr after the first and the last sessions showed no attenuation of force decline with supplementation. Muscle soreness following the first and last sessions was not different between groups. The authors concluded that neither HMB-Ca nor HMB-FA improved hypertrophy or reduced muscle damage in resistance-trained men undergoing resistance training ingesting optimal amounts of protein. HMB-FA but not HMB-Ca resulted in a statistically significant yet minor improvement on leg press one-repetition maximum.

Effect of rapid weight loss and glutamine supplementation on immunosuppression of combat athletes: a double-blind, placebo-controlled study.

The role of plasma glutamine concentration and glutamine supplementation on immunosuppression was investigated in combat athletes. Twenty-three male athletes were randomly assigned to receive glutamine (21 g/day, n=12) or placebo (ovalbumin, n=11) for 10 days. Six athletes who did not lose weight served as controls. Athletes were assessed 21 days before (-21d), 1 day before (-1d) and 5 days after (+5d) a competition. Weight reduction was similar between glutamine (-8.2%± 4.1%) and placebo (-8.5%±2.4%) and negligible in control (-0.6%±1.4%). In both weight-loss groups, the majority of athletes reported symptoms of upper respiratory symptoms, as assessed by the Wisconsin upper respiratory symptom survey questionnaire. Only two athletes reported symptoms in the control group. Immune cell function remained unchanged throughout the study except for an increase in neutrophil phagocytic activity (placebo: -21d=5,251±2,986; -1d=17,428±22,374; +5d=21,125±21,934; glutamine: -21d=6,096±3,549; -1d=11,029±17,113; +5d=28,186±21,032 FI) and a minor change in monocyte phagocytic activity (placebo: -21d=4,421±3,634; -1d=3,329±6,283; +5d=3,243± 2,553; glutamine: -21d=4,051±3,186; -1d=3,106±2,625; +5d=4,981± 4,598) in both glutamine and placebo after weight loss. Plasma glutamine and cortisol remained unchanged across the study. creatine kinase levels were increased in placebo (-21d=125.2±54.1; -1d=187.2± 73.5; +5d=111.3±59.1 U/L) but not in glutamine (-21d=136.2±58.2; -1d= 168.8±65.0; +5d=129.7±64.0 U/L). Rapid weight loss increased the frequency and severity of infection symptoms, but this was neither associated with plasma glutamine depletion nor counteracted by glutamine supplementation.

Effect of rapid weight loss on performance in combat sport male athletes: does adaptation to chronic weight cycling play a role?

BACKGROUND: Studies failing to show a negative effect of rapid weight loss (RWL) on performance have been conducted in athletes who have been cycling weight for years. It has been suggested that chronic weight cycling could lead combat athletes to become resistant to the stresses associated with weight loss. To investigate the effects of RWL up to 5% of body mass on high-intensity intermittent performance in weight cyclers (WC) and non-weight cyclers (non-WC). METHODS: Eighteen male combat athletes (WC: n=10; non-WC: n=8) reduced up to 5% of their body mass in 5 days. Body composition, high-intensity performance and plasma lactate were assessed preweight loss and postweight loss. Athletes had 4 h to re-feed and rehydrate following the weigh-in. Food intake was recorded during the weight loss and the recovery periods. RESULTS: Athletes significantly decreased body mass, lean body mass (most likely due to fluid loss) and fat mass following weight loss. No significant changes in performance were found from preweight loss to postweight loss in both groups. Plasma lactate was significantly elevated after exercise in both groups, but no differences were found between groups and in response to RWL. For all these variables no differences were observed between groups. Athletes from both groups ingested high amounts of energy and carbohydrates during the recovery period after the weigh-in. CONCLUSIONS: Chronic weight cycling does not protect athletes from the negative impact of RWL on performance. The time to recover after weigh-in and the patterns of food and fluid ingestion during this period is likely to play the major role in restoring performance to baseline levels.

Creatine supplementation in fibromyalgia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To investigate the efficacy and safety of creatine supplementation in fibromyalgia patients. METHODS: A 16-week, randomized, double-blind, placebo-controlled, parallel-group trial was conducted. Fibromyalgia patients were randomly assigned to receive either creatine monohydrate or placebo in a double-blind manner. The patients were evaluated at baseline and after 16 weeks. Muscle function, aerobic conditioning, cognitive function, quality of sleep, quality of life, kidney function, and adverse events were assessed. Muscle phosphorylcreatine content was measured through (31) P magnetic resonance spectroscopy. RESULTS: After the intervention, the creatine group presented higher muscle phosphorylcreatine content when compared with the placebo group (+80.3% versus -2.7%; P = 0.04). Furthermore, the creatine group presented greater muscle strength than the placebo group in the leg press and chest press exercises (+9.8% and +1.2% for creatine versus -0.5% and -7.2% for placebo, respectively; P = 0.02 and P = 0.002, respectively). Isometric strength was greater in the creatine group than in the placebo group (+6.4% versus -3.2%; P = 0.007). However, no general changes were observed in aerobic conditioning, pain, cognitive function, quality of sleep, and quality of life. Food intake remained unaltered and no side effects were reported. CONCLUSION: Creatine supplementation increased intramuscular phosphorylcreatine content and improved lower- and upper-body muscle function, with minor changes in other fibromyalgia features. These findings introduce creatine supplementation as a useful dietary intervention to improve muscle function in fibromyalgia patients.