Moderate Exercise Based on Artificial Gravity Preserves Orthostatic Tolerance and Exercise Capacity During Short-Term Head-Down Bed Rest
Moderate Exercise Based on Artificial Gravity Preserves Orthostatic Tolerance and Exercise Capacity During Short-Term Head-Down Bed Rest
复制标题
基于人工重力的适度运动可在短期低头卧床休息期间保持直立耐受力和运动能力
DOI：
10.33549/physiolres.933493
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发表时间：
2017-01-01
影响因子：
2.1
通讯作者：
Sun, Xi-Qing
中科院分区：
文献类型：
--
作者：
Li, Xiao-Tao;Yang, Chang-Bin;Sun, Xi-Qing
已经提出了许多对策，以尽量减少微重力引起的物理失调，但其好处是有限的。本研究旨在探讨基于人工重力（AG）的个性化有氧运动是否能减轻多系统身体失调。14名男性被分配到对照组（n=6）和对策组（CM，n= 8）。CM组受试者暴露于AG（足水平2Gz），每天两次，每次30 min，在此期间进行80- 95%无氧阈值（AT）强度的自行车运动。在头低位卧床休息（HDBR）前后测定立位耐力（OT）、运动试验和血液分析。每天测量心脏收缩功能。HDBR后，对照组和CM组的OT分别下降至HDBR前值的50.9%和77.5%。在对照组中，运动耐力、最大耗氧量和AT分别下降至HDBR前值的96.5%、91.5%和91.8%。然而，CM组有轻微变化。HDBR增加心率，交感神经活动，射血前期，但减少血浆容量，副交感神经活动和左心室射血时间在对照组，而这些影响被消除在CM组。对照组醛固酮无变化，CM组显著升高。我们的研究表明，在2 Gz AG的基础上进行80- 95%AT有氧运动，可以保持OT和运动耐力，并影响短期HDBR期间的体液调节。其潜在机制可能涉及维持心脏收缩功能，保留血浆容量，改善对直立应激的交感神经反应。
Numerous countermeasures have been proposed to minimize microgravity-induced physical deconditioning, but their benefits are limited. The present study aimed to investigate whether personalized aerobic exercise based on artificial gravity (AG) mitigates multisystem physical deconditioning. Fourteen men were assigned to the control group (n=6) and the countermeasure group (CM, n= 8). Subjects in the CM group were exposed to AG (2 Gz at foot level) for 30 min twice daily, during which time cycling exercise of 80-95 % anaerobic threshold (AT) intensity was undertaken. Orthostatic tolerance (OT), exercise tests, and blood assays were determined before and after 4 days head-down bed rest (HDBR). Cardiac systolic function was measured every day. After HDBR, OT decreased to 50.9 % and 77.5 % of pre-HDBR values in control and CM groups, respectively. Exercise endurance, maximal oxygen consumption, and AT decreased to 96.5 %, 91.5 % and 91.8 % of pre-HDBR values, respectively, in the control group. Nevertheless, there were slight changes in the CM group. HDBR increased heart rate, sympathetic activity, and the pre-ejection period, but decreased plasma volume, parasympathetic activity and left-ventricular ejection time in the control group, whereas these effects were eliminated in the CM group. Aldosterone had no change in the control group but increased significantly in the CM group. Our study shows that 80-95 % AT aerobic exercise based on 2 Gz of AG preserves OT and exercise endurance, and affects body fluid regulation during short-term HDBR. The underlying mechanisms might involve maintained cardiac systolic function, preserved plasma volume, and improved sympathetic responses to orthostatic stress.