Department for Life Quality Studies, University of Bologna, 47921 Rimini, Italy.
CIDEFES - Universidade Lusófona, 1749-024 Lisboa, Portugal.
Appl Physiol Nutr Metab. 2021 Jun;46(6):669-675. doi: 10.1139/apnm-2020-0915. Epub 2020 Dec 18.
We aimed to assess the effects of off-the-shelf leucine metabolite supplements on phase angle (PhA), bioimpedance vector analysis (BIVA) patterns and strength during an 8-week resistance training protocol. Fifty-three male participants were allocated into 4 groups: α-hydroxyisocaproic acid ( = 12, age = 30.9 ± 9.3 years), β-hydroxy-β-methylbutyrate free acid ( = 12, age = 31.0 ± 9.3 years), calcium β-hydroxy-β-methylbutyrate ( = 15, age = 32.1 ± 5.2 years) or placebo ( = 14, age = 28.9 ± 6.6 years). Bioimpedance parameters and 1-repetition maximum (1RM) for back squat and bench press were assessed at baseline and at the end of weeks 4 and 8. Additionally, fat-free mass and fat mass were evaluated by dual-energy X-ray absorptiometry. No statistically group by time interactions were found, even adjusting for age. PhA and vector did not change over the training period, while time-dependent increases were observed for 1RM back squat and 1RM bench press. A direct association was observed between PhA and 1RM bench press changes (whole sample), while PhA and strength were correlated throughout the study, even when adjusting for fat-free mass and percentage of fat mass. Leucine metabolites have no effect on PhA, BIVA patterns or strength during an 8-week resistance training program, in resistance trained subjects. The trial was registered at ClincicalTrials.gov: NCT03511092. Supplementation with leucine metabolites is not a supplementation strategy that improves bioelectrical phase angle, cellular health, and strength after an 8-week resistance training program. When consuming a high protein diet, none of the α-hydroxyisocaproic acid, β-hydroxy-β-methylbutyrate free acid, and calcium β-hydroxy-β-methylbutyrate metabolites resulted in an ergogenic effect in resistance trained men.
我们旨在评估现成的亮氨酸代谢物补充剂对相位角（PhA）、生物阻抗向量分析（BIVA）模式和力量的影响，为期 8 周的抗阻训练方案。53 名男性参与者被分配到 4 组：α-羟基异己酸（=12，年龄=30.9±9.3 岁）、β-羟基-β-甲基丁酸游离酸（=12，年龄=31.0±9.3 岁）、钙 β-羟基-β-甲基丁酸（=15，年龄=32.1±5.2 岁）或安慰剂（=14，年龄=28.9±6.6 岁）。在基线和第 4 周和第 8 周结束时，评估生物阻抗参数和 1 次重复最大重量（1RM）的深蹲和卧推。此外，通过双能 X 射线吸收法评估去脂体重和脂肪量。即使调整年龄，也未发现组间时间交互作用。在训练期间，PhA 和向量没有变化，而 1RM 深蹲和 1RM 卧推则呈时间依赖性增加。整个样本中观察到 PhA 与 1RM 卧推变化之间存在直接关联，而 PhA 与力量在整个研究中均相关，即使调整去脂体重和脂肪百分比也是如此。在 8 周抗阻训练计划中，亮氨酸代谢物对 PhA、BIVA 模式或力量没有影响，在抗阻训练的受试者中。该试验在 ClincicalTrials.gov 注册：NCT03511092。补充亮氨酸代谢物不是一种在 8 周抗阻训练计划后改善生物电阻抗相位角、细胞健康和力量的补充策略。在摄入高蛋白饮食时，α-羟基异己酸、β-羟基-β-甲基丁酸游离酸和钙 β-羟基-β-甲基丁酸代谢物均未对抗阻训练的男性产生任何增效作用。
