Scott Jessica M, Hackney Kyle, Downs Meghan, Guined Jamie, Ploutz-Snyder Robert, Fiedler James, Cunningham David, Ploutz-Snyder Lori
Aviat Space Environ Med. 2014 Jun;85(6):612-7. doi: 10.3357/asem.3772.2014.
Exercise countermeasures designed to mitigate muscle atrophy during long-duration spaceflight may not be as effective if crewmembers are in negative energy balance (energy output > energy input). This study determined the energy cost of supine exercise (resistance, interval, aerobic) during the spaceflight analogue of bed rest.
Nine subjects (eight men and one woman; 34.5 +/- 8.2 yr) completed 14 d of bed rest and concomitant exercise countermeasures. Body mass and basal metabolic rate (BMR) were assessed before and during bed rest. Exercise energy expenditure was measured during and immediately after [excess post-exercise oxygen consumption (EPOC)] each of five different exercise protocols (30-s, 2-min, and 4-min intervals, continuous aerobic, and a variety of resistance exercises) during bed rest.
On days when resistance and continuous aerobic exercise were performed daily, energy expenditure was significantly greater (2879 +/- 280 kcal) than 2-min (2390 +/- 237 kcal), 30-s (2501 +/- 264 kcal), or 4-min (2546 +/- 264 kcal) exercise. There were no significant differences in BMR (pre-bed rest: 1649 +/- 216 kcal; week 1: 1632 +/- 174 kcal; week 2:1657 +/- 176 kcal) or body mass (pre-bed rest: 75.2 +/- 10.1 kg; post-bed rest: 75.2 +/- 9.6 kg).
These findings highlight the importance of energy balance for long-duration crewmembers completing a high-intensity exercise program with multiple exercise sessions daily.
如果机组人员处于负能量平衡状态（能量输出>能量输入），旨在减轻长期太空飞行期间肌肉萎缩的运动对策可能效果不佳。本研究确定了卧床休息这一太空飞行模拟期间仰卧运动（抗阻运动、间歇运动、有氧运动）的能量消耗。
9名受试者（8名男性和1名女性；34.5±8.2岁）完成了14天的卧床休息及相应的运动对策。在卧床休息前和期间评估体重和基础代谢率（BMR）。在卧床休息期间，对五种不同运动方案（30秒、2分钟和4分钟间歇运动、持续有氧运动以及各种抗阻运动）中的每一种运动期间及运动后立即测量运动能量消耗[运动后过量氧耗（EPOC）]。
在每天进行抗阻运动和持续有氧运动的日子里，能量消耗（2879±280千卡）显著高于2分钟运动（2390±237千卡）、30秒运动（2501±264千卡）或4分钟运动（2546±264千卡）。基础代谢率（卧床休息前：1649±216千卡；第1周：1632±174千卡；第2周：1657±176千卡）或体重（卧床休息前：75.2±10.1千克；卧床休息后：75.2±9.6千克）没有显著差异。
这些发现凸显了能量平衡对于长期执行任务的机组人员完成每日多次高强度运动计划的重要性。
