Atkinson G, Barr D, Chester N, Drust B, Gregson W, Reilly T, Waterhouse J
Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
Int J Sports Med. 2008 Mar;29(3):188-93. doi: 10.1055/s-2007-965161. Epub 2007 Sep 13.
The thermoregulatory responses to morning exercise after exposure to different schedules of bright light were examined. At 07:00 h, six males ran on two occasions in an environmental chamber (temperature = 31.4 +/- 1.0 degrees C, humidity = 66 +/- 6 %) for 40 min at 60 % of maximal oxygen uptake. Participants were exposed to bright light (10,000 lux) either between 22:00 - 23:00 h (BT (low)) or 06:00 - 07:00 h (BT (high)). Otherwise, participants remained in dim light (< 50 lux). It was hypothesized that BT (low) attenuates core temperature during morning exercise via the phase-delaying properties of evening bright light and by avoiding bright light in the morning. Evening bright light in BT (low) suppressed (p = 0.037) the increase in melatonin compared to dim light (1.1 +/- 11.4 vs. 15.2 +/- 19.7 pg x ml (-1)) and delayed (p = 0.034) the core temperature minimum by 1.46 +/- 1.24 h. Core temperature was 0.20 +/- 0.17 degrees C lower in BT (low) compared to BT (high) during the hour before exercise (p = 0.036), with evidence (p = 0.075) that this difference was maintained during exercise. Conversely, mean skin temperature was 1.0 +/- 1.7 degrees C higher during the first 10 min of exercise in BT (low) than in BT (high) (p = 0.030). There was evidence that the increase in perceived exertion was attenuated in BT (low) (p = 0.056). A chronobiologically-based light schedule can lower core temperature before and during morning exercise in hot conditions.
研究了暴露于不同明亮光照时间表后，晨练时的体温调节反应。早上7点，6名男性在环境舱（温度=31.4±1.0摄氏度，湿度=66±6%）中，以最大摄氧量的60%的强度跑步40分钟，共进行两次。参与者在22:00 - 23:00（BT（低））或06:00 - 07:00（BT（高））期间暴露于强光（10000勒克斯）下。否则，参与者处于暗光（<50勒克斯）环境中。研究假设BT（低）通过夜间强光的相位延迟特性以及避免早晨的强光，在晨练期间降低核心体温。与暗光相比，BT（低）中的夜间强光抑制了褪黑素的增加（p = 0.037）（1.1±11.4 vs. 15.2±19.7 pg x ml（-1）），并使核心体温最低值延迟了1.46±1.24小时（p = 0.034）。在运动前一小时，BT（低）组的核心体温比BT（高）组低0.20±0.17摄氏度（p = 0.036），有证据表明（p = 0.075），这种差异在运动期间持续存在。相反，在BT（低）组运动的前10分钟，平均皮肤温度比BT（高）组高1.0±1.7摄氏度（p = 0.030）。有证据表明，BT（低）组中主观用力程度的增加有所减弱（p = 0.056）。基于生物钟学的光照时间表可以在炎热条件下晨练前和晨练期间降低核心体温。
