Functional losses associated with spaceflight negatively influence astronaut health and mission success. Exercise combined with protein supplementation is a promising countermeasure. Blood flow restricted (BFR) exercise is an effective modality, but synergistic benefits when combined with protein supplementation are not clearly identified. The purposes of this investigation were to determine if blended (e.g., whey and casein) protein supplementation combined with BFR exercise favorably altered body composition, muscle function, and cardiovascular health during a short training program.

Methods

Sixteen participants (female = 50%, age = 36.0 ± 10.1 y, BMI = 27.2 ± 5.0 kg/m²) completed a six-week, ground-based, double-blind, placebo controlled, clinical trial. Participants were randomly assigned to daily blended protein supplementation (28 g protein with 3 g leucine) or an isocaloric placebo. Pre-and post-intervention, body composition, muscular strength and function, balance, and cardiovascular health were evaluated. Dietary intake was evaluated pre-, mid-, and post-intervention.

Results

Dietary protein intakes for the supplement and placebo groups, respectively, were beyond adequate (1.6 ± 0.2 g kg·day⁻¹ and 1.0 ± 0.2 g kg·day⁻¹; p = 0.004) and remained consistent throughout the study. However, total leucine intake increased from 3.5 ± 3.2 g·day⁻¹ to 5.6 ± 1.5 g·day⁻¹ following supplementation (p = 0.002). Post-training, knee flexor strength, sit-to-stand repetitions, and gait speed significantly increased, while resting heart rate declined (p < 0.05), with no between group differences.

Conclusion

Exercise with intermittent BFR improves muscular strength and function while positively influencing cardiovascular health in adults. The leucine-rich protein supplement provided no additional benefits. These data suggest potential as an adjunct countermeasure for negative effects of disuse; however, further spaceflight analog-specific data are required before implementation.

中文翻译：

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间歇性血流限制运动可迅速改善蛋白质摄入不足的成年人的肌肉和心血管健康

与太空飞行相关的功能损失会对宇航员的健康和任务成功产生负面影响。运动与蛋白质补充相结合是一种很有前途的对策。血流受限 (BFR) 运动是一种有效的方式，但与蛋白质补充剂相结合时的协同作用尚未明确确定。这项调查的目的是确定在短期训练计划中，混合（例如，乳清和酪蛋白）蛋白质补充剂与 BFR 运动相结合是否有利地改变了身体成分、肌肉功能和心血管健康。

方法

16 名参与者（女性 = 50%，年龄 = 36.0 ± 10.1 岁，BMI = 27.2 ± 5.0 kg/m ²）完成了为期六周的、基于地面的、双盲、安慰剂对照的临床试验。参与者被随机分配到每日混合蛋白质补充剂（28 g 蛋白质和 3 g 亮氨酸）或等热量安慰剂。对干预前后的身体成分、肌肉力量和功能、平衡和心血管健康进行了评估。膳食摄入量在干预前、干预中和干预后进行了评估。

结果

补充剂组和安慰剂组的膳食蛋白质摄入量分别超过了充足量（1.6 ± 0.2 g kg·day ^-1和 1.0 ± 0.2 g kg·day ^-1；p = 0.004），并且在整个研究过程中保持一致。然而，补充后的总亮氨酸摄入量从 3.5 ± 3.2 g·day ^-1增加到 5.6 ± 1.5 g·day ^-1 (p = 0.002)。训练后，膝屈肌力量、坐站重复次数和步态速度显着增加，而静息心率下降（p < 0.05），组间无差异。

结论

间歇性 BFR 锻炼可提高肌肉力量和功能，同时对成人的心血管健康产生积极影响。富含亮氨酸的蛋白质补充剂没有提供额外的好处。这些数据表明有可能作为废用负面影响的辅助对策；然而，在实施之前还需要更多的航天模拟数据。