Yamanaka Yujiro, Hashimoto Satoko, Masubuchi Satoru, Natsubori Akiyo, Nishide Shin-Ya, Honma Sato, Honma Ken-Ichi
Departments of Physiology.
Research Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Am J Physiol Regul Integr Comp Physiol. 2014 Sep 1;307(5):R546-57. doi: 10.1152/ajpregu.00087.2014. Epub 2014 Jun 18.
Our previous study demonstrated that physical exercise under dim lights (<10 lux) accelerated reentrainment of the sleep-wake cycle but not the circadian melatonin rhythm to an 8-h phase-advanced sleep schedule, indicating differential effects of physical exercise on the human circadian system. The present study examined the effects of bright light (>5,000 lux) on exercise-induced acceleration of reentrainment because timed bright lights are known to reset the circadian pacemaker. Fifteen male subjects spent 12 days in temporal isolation. The sleep schedule was advanced from habitual sleep times by 8 h for 4 days, which was followed by a free-run session. In the shift session, bright lights were given during the waking time. Subjects in the exercise group performed 2-h bicycle running twice a day. Subjects in the control kept quiet. As a result, the sleep-wake cycle was fully entrained by the shift schedule in both groups. Bright light may strengthen the resetting potency of the shift schedule. By contrast, the circadian melatonin rhythm was phase-advanced by 6.9 h on average in the exercise group but only by 2.0 h in the control. Thus physical exercise prevented otherwise unavoidable internal desynchronization. Polysomnographical analyses revealed that deterioration of sleep quality by shift schedule was protected by physical exercise under bright lights. These findings indicate differential regulation of sleep-wake cycle and circadian melatonin rhythm by physical exercise in humans. The melatonin rhythm is regulated primarily by bright lights, whereas the sleep-wake cycle is by nonphotic time cues, such as physical exercise and shift schedule.
我们之前的研究表明，在昏暗灯光（<10勒克斯）下进行体育锻炼可加速睡眠-清醒周期的重新调整，但对于向提前8小时的睡眠时间表调整昼夜褪黑素节律却无此作用，这表明体育锻炼对人体昼夜节律系统有不同影响。本研究考察了强光（>5000勒克斯）对运动诱导的重新调整加速的影响，因为已知定时强光可重置昼夜节律起搏器。15名男性受试者进行了12天的时间隔离。睡眠时间表从习惯睡眠时间提前8小时，持续4天，随后是自由运行期。在调整期，在清醒时间给予强光。运动组的受试者每天进行两次2小时的自行车骑行。对照组的受试者保持安静。结果，两组的睡眠-清醒周期均被调整时间表完全调整。强光可能会增强调整时间表的重置效力。相比之下，运动组的昼夜褪黑素节律平均提前了6.9小时，而对照组仅提前了2.0小时。因此，体育锻炼防止了原本不可避免的内部不同步。多导睡眠图分析显示，在强光下进行体育锻炼可保护因调整时间表导致的睡眠质量下降。这些发现表明，体育锻炼对人类的睡眠-清醒周期和昼夜褪黑素节律有不同的调节作用。褪黑素节律主要受强光调节，而睡眠-清醒周期则受非光时间线索调节，如体育锻炼和调整时间表。
