B-10 Basic Science World Congress - Thematic Poster - Moderating Skeletal Muscle I Wednesday, May 30, 2018, 1: 00 PM - 3: 00 PM Room: CC-Mezzanine M100C
Some leucine metabolites like β-hydroxy-β-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxy-isocaproic acid (α-HICA or leucic acid) have been suggested to augment training-induced adaptations in body composition and performance.
PURPOSE: To compare the effects of commercially available supplements, HMB- Ca, HMB-FA and α-HICA, on resistance training-induced changes in fat mass and fat-free mass (FFM) and performance.
METHODS: Forty men were block-randomized (based on handgrip strength, age, and fat-free mass [FFM]) to one of four groups: HMB-FA (n=11, age 30 ± 2.4 y, FFM 62.7 ± 10.5 kg), HMB-Ca (n=9, age 34 ± 1.5 y, FFM 65.6 ± 10.1 kg), α-HICA group (n=10, age 31 ± 2.7 y FFM 62.0 ± 7.1 kg), and placebo (PLA) group (n=10, age 31 ± 2.1 y FFM 64.2 ± 5.7 kg). The training program consisted of whole body thrice weekly training for 8wk (7 exercises/session, 3-4 sets per session, 70-80% 1RM). Whole body fat and FFM were assessed by DXA, and performance measures (vertical jump, 1RM for bench press, squat and Wingate test) were all assessed at baseline and at the end of weeks 4 and 8. Participants were instructed to consume at least 45 kcal/kg FFM/d and 1.6 g protein/kg body weight/d.
RESULTS: Time-dependent changes were observed for 1RM bench press (p < 0.001), 1RM Squat (p < 0.001), vertical jump height (p = 0.028) and vertical jump power (p = 0.006). No significant between-group or time-group interactions were observed for body weight, Wingate peak and average power, handgrip, whole body fat or whole body FFM (Δ changes: HMB-FA 0.1 ± 1.5 kg; PLA 0.6 ± 0.8 kg; α-HICA -0.1 ± 1.0 kg; HMB-Ca 0.6 ± 2.0 kg)
CONCLUSION: When consuming sufficient protein while in an estimated positive energy balance, none of the leucine metabolites studied resulted in any ergogenic effects on any outcome variable. We do not recommend leucine metabolites as a supplement strategy to augment training-induced gains in performance or body composition.