Huschtscha Zoya, Parr Alexandra, Porter Judi, Costa Ricardo J S
Department of Nutrition Dietetics & Food, Monash University, Notting Hill, VIC, Australia.
School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia.
Front Nutr. 2021 Mar 17;8:644865. doi: 10.3389/fnut.2021.644865. eCollection 2021.
The study aimed to investigate the independent and combined effects of consuming a high-protein dairy milk beverage, twice daily, with or without a progressive resistance training (PRT) program on outcomes of age-related sarcopenia, in healthy active older (≥50 years) adults. In this 12-week, 2 × 2 factorial study, participants were randomly allocated into one of four groups: dairy milk beverage (DM), exercise and dairy milk beverage (EX+DM), exercise alone (EX), and control (CON). The EX group underwent a 12-week whole-body PRT schedule (three sessions/week) and a high-protein dairy milk beverage (DM) was consumed twice daily (30 g protein/day). At weeks 0, 6, and 12, body composition (iDXA), strength [one-repetition maximum (1RM): leg press, chest press, lateral () pull-down, and handgrip], power (countermovement jump), cardiorespiratory fitness (O), and physical performance (gait speed) were measured. Before measurements, blood samples were collected to determine the immune (i.e., leukocyte trafficking and inflammatory cytokines) and hormonal (i.e., insulin, cortisol, IGF-1, testosterone, and estradiol) profiles. Participants ( = 37) completed the study within the controlled experimental conditions. Protein intake increased in the EX+DM [mean ± SD, 1.2 ± 0.2 to 1.8 ± 0.4 g/kg body mass (BM) per day] and DM (1.3 ± 0.5 to 1.8 ± 0.6 g kg BM day) groups during the intervention. Absolute fat-free mass increased in the EX+DM [mean (95% confidence interval) = 0.65 (0.25-1.0) kg] and EX [0.49 (-0.44 to 1.40) kg] groups ( < 0.001) compared to DM [-0.54 (-1.6 to 0.05) kg]. Relative fat mass decreased (grouptime, = 0.018) in DM [-1.8% (-3.3 to -0.35%)] and EX+DM [-1.3% (-2.3 to -0.31%)], which was a greater reduction than that in the CON [0.10% (-0.80 to 1.0%)] group (P < 0.01). Relative maximal strength increased in both the EX and EX+DM (≥35%, < 0.05) groups, but not in the DM and CON groups. The change in 1RM strength outcomes was higher in EX+DM compared to all other groups (53-78%, < 0.01). There was an increase in resting plasma IL-10 concentration in EX+DM (88%), compared to all the other groups ( = 0.016). No other differences in systemic inflammatory cytokines were observed. There were no significant changes in all hormone concentrations measured among all groups. In conclusion, a high-protein dairy milk beverage providing additional protein did not further enhance the effects of PRT on outcomes of fat-free mass, power, or physical performance. However, there was a significant augmentative effect for high-protein dairy milk consumption on changes to maximal strength outcomes during PRT in healthy active older adults.
该研究旨在调查每日两次饮用高蛋白乳制饮品，无论有无进行渐进性抗阻训练（PRT）计划，对健康活跃的老年人（≥50岁）与年龄相关的肌肉减少症各项指标的独立及联合影响。在这项为期12周的2×2析因研究中，参与者被随机分为四组之一：乳制饮品组（DM）、运动加乳制饮品组（EX+DM）、单独运动组（EX）和对照组（CON）。EX组进行了为期12周的全身PRT计划（每周三次训练），且每日饮用两次高蛋白乳制饮品（每日30克蛋白质）。在第0、6和12周时，测量了身体成分（iDXA）、力量[一次重复最大值（1RM）：腿举、卧推、坐姿下拉和握力]、功率（反向纵跳）、心肺适能（O）和身体表现（步速）。在测量前，采集血样以确定免疫（即白细胞运输和炎性细胞因子）和激素（即胰岛素、皮质醇、胰岛素样生长因子-1、睾酮和雌二醇）谱。参与者（n = 37）在受控的实验条件下完成了研究。干预期间，EX+DM组[平均值±标准差，从每天1.2±0.2增至1.8±0.4克/千克体重（BM）]和DM组（从1.3±0.5增至1.8±0.6克/千克BM/天）的蛋白质摄入量增加。与DM组[-0.54（-1.6至0.05）千克]相比，EX+DM组[平均值（95%置信区间）= 0.65（0.25 - 1.0）千克]和EX组[0.49（-0.44至1.40）千克]的绝对去脂体重增加（P < 0.001）。DM组[-1.8%（-3.3至-0.35%）]和EX+DM组[-1.3%（-2.3至-0.31%）]的相对脂肪量减少（组×时间，P = 0.018），且减少幅度大于CON组[仅0.10%（-0.80至1.0%）]（P < 0.01）。EX组和EX+DM组的相对最大力量均增加（≥35%，P < 0.05），而DM组和CON组未增加。与所有其他组相比，EX+DM组1RM力量指标的变化更高（53 - 78%，P < 0.01）。与所有其他组相比，EX+DM组静息血浆白细胞介素-10浓度增加（88%）（P = 0.016）。未观察到全身炎性细胞因子的其他差异。所有组测量的所有激素浓度均无显著变化。总之，提供额外蛋白质的高蛋白乳制饮品并未进一步增强PRT对去脂体重、功率或身体表现各项指标的影响。然而，对于健康活跃的老年人，饮用高蛋白乳制饮品对PRT期间最大力量指标的变化有显著的增强作用。
