@article{oai:jaxa.repo.nii.ac.jp:00021552,
 author = {水野, 康 and 大島, 博 and Mizuno, Koh and Ohshima, Hiroshi},
 issue = {2},
 journal = {宇宙航空環境医学, Japanese journal of aerospace and environmental medicine},
 month = {Jun},
 note = {In a large bed rest study simulating long duration space flight, sleep/wake rhythm was evaluated in combination with rectal temperature rhythm. The subjects were sixteen health males (age: 32.7 +/- 4.0 yrs; height: 175 +/- 5 cm; weight: 70.8 +/- 6.8 kg; mean +/- SD) who completed 90 days 6 degrees head-down bed rest. Seven subjects spent bed rest period without physical training. The other nine subjects performed exercise countermeasure conducting leg resistive exercise every third day. Rectal temperature rhythm was assessed by 72 hours of continuous measurements performed once before and four times during bed rest (days 9-11, 35-37, 65-67, and 85-88). In the continuous recordings of wrist actigraphy performed from one week before through the end of bed rest, weekly average values of total sleep time in nocturnal sleep and daytime napping, and timing of sleep onset and termination were calculated when rectal temperature was recorded. No significant effect of exercise was found in any measurements suggesting that amount of exercise (about 30 minutes for one day x 2.5 day a week) was insufficient to induce significant changes in sleep and circadian rhythm parameters. Weekly average values of nocturnal sleep time ranged between 370 and 450 minutes during bed rest, and were higher than those before bed rest. Scheduled daytime activities to prevent boredom during bed rest might lead to relatively less amount of daytime napping (weekly average values ranged between 30 and 80 minutes), which might have little unfavorable effect on nocturnal sleep. Although amplitude of rectal temperature rhythm showed no significant change, delayed phase ranged from 20 to 40 minutes was consistently observed during bed rest. As delayed phase was also induced in nocturnal sleep onset and termination, the most remarkable phase delay around 1 hour was found in sleep termination in the morning despite constant time to turn on the room light throughout the experimental period. These results suggested that, in addition to physiological phase delay in circadian rhythm, difficulty waking up or longer sleep inertia in the morning might occur under the bed rest condition., 資料番号: DS0049721001},
 pages = {55--63},
 title = {90日間の6度ヘッドダウンベッドレストにおける睡眠・覚醒および直腸温リズム},
 volume = {43},
 year = {2006}
}