太空失重会对人体产生一系列不良影响，而运动锻炼可能是对抗失重生理效应最为有效的措施之一。因此，有必要对长期模拟失重期间不同运动锻炼对人体运动能力的影响开展深入研究。

研究目的：观察长期模拟失重期间人体运动能力的改变规律，探讨模拟失重期间不同运动锻炼模式对人体运动能力的影响及可能机制，探寻更为有效的基于运动锻炼的失重防护方案，为中国空间站航天员长期在轨驻留期间的运动锻炼失重防护提供理论与实验依据。

研究方法：36名健康男性志愿者随机分为对照组（C组，n = 8）、跑台锻炼组（T组，n = 7）、抗阻锻炼组（R组，n = 7）、以有氧锻炼为主的综合防护组（A组，n = 7）和有氧抗阻锻炼并重的综合防护组（B组，n = 7）。采用90天 - 6°头低位卧床模拟失重（Head down bed rest，HDBR）建立长期失重人体实验模型。在HDBR前7天，HDBR期间的第15天、第45天、第71天以及HDBR后第2天进行递增负荷运动测试，在HDBR前3天和HDBR后第5天进行一次无氧功测试。

研究结果：

（1）长期模拟失重可导致人体有氧运动能力大幅下降，HDBR后递增负荷运动测试时无氧阈对应的摄氧量（AT_vo2）显著下降（P<0.01），下降幅度高达30.01%左右，无氧阈出现的时间点（AT_time）显著缩短（P<0.01），缩短幅度高达16.05%。

（2）长期模拟失重可导致人体无氧运动能力大幅下降，HDBR后无氧功测试中的峰值功率输出（Power_peak）显著下降（P<0.01），下降幅度高达20.62%左右，平均值功率（Power_avg）输出显著下降（P<0.01），下降幅度高达16.61%。

（3）长期模拟失重可导致中小负荷运动能力大幅降低，HDBR后单位耗氧量的功率输出（PO_w）显著升高（P<0.05），单位时间的功率输出（P_w）非常显著的降低P<0.01）；反映肌群总体做功能力显著下降，快-慢肌做功能力均衡性中慢肌受损更为严重。

（4）跑台锻炼可有效对抗长期模拟失重导致的有氧运动能力下降，HDBR后AT_vo2、AT_time、PO_w、P_w均无显著改变；但对无氧运动能力的防护较为有限，HDBR后Power_peak仍显著下降（P<0.01）。

（5）抗阻锻炼可有效对抗长期模拟失重导致的无氧运动能力下降，HDBR后Power_peak无显著改变；但对有氧运动能力的防护效果较为有限，HDBR后AT_vo2、PO_w显著的下降（P<0.05）。

（6）有氧锻炼为主抗阻锻炼为辅的综合锻炼防护措施对有氧运动能力有较好的防护效果，HDBR后AT_vo2、AT_time、PO_w、P_w均无显著改变；但对无氧运动能力的防护较为有限，HDBR后Power_peak仍显著下降（P<0.01）。

（7）抗阻锻炼和有氧锻炼并重的综合锻炼防护对有氧和无氧运动能力均有较好的防护效果， HDBR后AT_vo2、AT_time、PO_w、P_w、Power_peak、Power_avg均无显著改变。

研究结论：长期模拟失重会对人体有氧及无氧运动能力产生严重不良影响，有氧锻炼可有效对抗有氧运动能力的下降，而抗阻锻炼可有效对抗无氧运动能力的下降，两者结合可同时对抗模拟失重导致的有氧及无氧运动能力下降，其中抗阻锻炼和有氧锻炼并重的方式更为有效。

Weightlessness in space will have a series of adverse effects on the human body, and exercise may be one of the most effective measures to combat the physiological effects of weightlessness. Therefore, it is necessary to carry out in-depth research on the effects of different exercise on human motor ability during long-term simulated weightlessness.

Purposes: To Observe the changing law of human movement ability during long-term simulated weightlessness, explore the effects and possible mechanisms of different exercise modes on human movement ability during simulated weightlessness, and explore more effective weightlessness protection schemes based on exercise, which will provide the Chinese space station astronauts with long-term experience in The weightlessness protection of exercise exercise during the orbital residence period provides theoretical and experimental basis.

Methods: Thirty-six healthy male volunteers were randomly divided into control group (group C, n = 8), treadmill exercise group (group T, n = 7), resistance exercise group (group R, n = 7), aerobic exercise-basedgroup comprehensive protection group (group A, n = 7), the comprehensive protection group with equal emphasis on aerobic exercise and resistance exercise (group B, n = 7). A long-term weightlessness human experimental model was established by 90 days - 6° head down bed rest (HDBR) to simulate weightlessness. 7 days before HDBR, day 15, day 45, day 71 during HDBR, and day 2 after HDBR, and an anaerobic work test was performed 3 days before HDBR and on day 5 after HDBR.

Results:

(1) Long-term simulated weightlessness can lead to a significant decrease in human aerobic exercise capacity. The oxygen uptake (AT_vo2) corresponding to the anaerobic threshold during the HDBR post-incremental load exercise test decreased significantly (P<0.01), and the decline range was as high as 30.01%, and the anaerobic threshold appeared. The time point (AT_time) was significantly shortened (P<0.01), and the shortening range was as high as 16.05%.

(2) Long-term simulated weightlessness can lead to a significant decrease in the human body's anaerobic exercise capacity. The peak power output (Power_peak) in the anaerobic power test after HDBR decreased significantly (P<0.01), and the decrease range was as high as 20.62%. The average power (Power_avg) output was significantly Decrease (P<0.01), the decreasing range is as high as 16.61%.

(3) Long-term simulated weightlessness can lead to a significant decrease in the exercise capacity of medium and small loads, the power output per unit of oxygen consumption (PO_w) after HDBR was significantly increased (P<0.05), and the power output per unit time (P_w) was extremely significantly decreased (P<0.01); It reflects the significant decrease in the overall performance of the muscle groups, and the damage to the slow and slow muscles is more serious in the balance of fast-slow muscle performance.

(4) Treadmill exercise can effectively combat the decline of aerobic exercise ability caused by long-term simulated weightlessness, and AT_vo2, AT_time, PO_w, and P_w have no significant changes after HDBR; however, the protection of anaerobic exercise ability is limited, and Power_peak is still significantly reduced after HDBR (P <0.01).

(5) Resistance exercise can effectively resist the decline of anaerobic exercise ability caused by long-term simulated weightlessness, and Power_peak has no significant change after HDBR; however, the protective effect on aerobic exercise ability is relatively limited, and AT_vo2 and PO_w decreased significantly after HDBR (P<0.05).

(6) The comprehensive exercise protection measures with aerobic exercise as the main resistance exercise supplemented by the resistance exercise have a good protective effect on the aerobic exercise capacity. There is no significant change in AT_vo2, AT_time, PO_w, and P_w after HDBR; however, the protection of the anaerobic exercise ability is relatively limited, Power_peak still decreased significantly after HDBR (P<0.01).

(7) The comprehensive exercise protection with equal emphasis on resistance exercise and aerobic exercise has a good protective effect on aerobic and anaerobic exercise capacity, and AT_vo2, AT_time, PO_w, P_w, Power_peak, and Power_avg have no significant changes after HDBR.

Conclusion:

Long-term simulated weightlessness will have serious adverse effects on human aerobic and anaerobic exercise capacity. Aerobic exercise can effectively combat the decline of aerobic exercise ability, while resistance exercise can effectively combat the decline of anaerobic exercise ability. To combat the decline of aerobic and anaerobic exercise capacity caused by simulated weightlessness, it is more effective to combine resistance exercise and aerobic exercise.