Vincent Grace E, Jay Sarah M, Sargent Charli, Kovac Katya, Vandelanotte Corneel, Ridgers Nicola D, Ferguson Sally A
Central Queensland University, Health, Medical and Applied Sciences, Wayville 5034, Australia.
Deakin University, Institute of Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Geelong, Australia.
Neurobiol Sleep Circadian Rhythms. 2017 Sep 14;4:17-23. doi: 10.1016/j.nbscr.2017.09.001. eCollection 2018 Jan.
To investigate the acute benefits of breaking up prolonged sitting with light-intensity physical activity on (i) glucose metabolism under conditions of sleep restriction, and (ii) cognitive deficits associated with sleep restriction.
This counterbalanced, crossover trial consisted of two five-day (5 night) experimental conditions separated by a two-week washout period. On the first night, participants were given a 9-h sleep opportunity to allow the collection of steady-state baseline measures the following day. This was followed by three consecutive nights of sleep restriction (5-h sleep opportunity). In the sitting condition (SIT), participants remained seated between 1000 and 1800 h. In the physical activity condition (ACT), participants completed 3-min bouts of light-intensity walking every 30 min on a motorised treadmill between 1000 and 1800 h. At all other times, in both conditions, participants remained seated, except when walking to the dining room or to use the bathroom (max distance = 32 m). Six physically inactive, healthy males were randomised to one of two trial orders, 1) SIT then ACT, or 2) ACT then SIT. Continuous measures of interstitial glucose were measured at 5-min intervals. A cognitive and subjective test battery was administered every two hours during wake periods. Analyses were conducted using a series of linear mixed-effect ANOVAs.
No differences in interstitial glucose concentration or cognitive performance were observed between the SIT condition and the ACT condition. Participants reported higher levels of sleepiness, and felt less alert in the SIT condition compared with the ACT condition.
There were no observable benefits of breaking up prolonged sitting on glucose metabolism under conditions of sleep restriction. These findings have implications for behaviour change interventions. Future studies will need to include larger, less homogenous study populations and appropriate control conditions (i.e., 8-9 h sleep opportunities).
研究通过轻度体力活动打破长时间久坐对（i）睡眠受限情况下的葡萄糖代谢，以及（ii）与睡眠受限相关的认知缺陷的急性益处。
这项平衡的交叉试验包括两个为期五天（五晚）的实验条件，中间间隔两周的洗脱期。在第一个晚上，给予参与者9小时的睡眠时间，以便在第二天收集稳态基线测量值。随后是连续三个晚上的睡眠受限（5小时睡眠时间）。在久坐条件（SIT）下，参与者在1000至1800时之间一直坐着。在体力活动条件（ACT）下，参与者在1000至1800时之间每30分钟在电动跑步机上进行3分钟的轻度步行。在所有其他时间，在两种条件下，参与者都一直坐着，除非走到餐厅或去洗手间（最大距离 = 32米）。六名身体不活跃的健康男性被随机分配到两种试验顺序之一，1）先SIT后ACT，或2）先ACT后SIT。每隔5分钟测量一次间质葡萄糖的连续测量值。在清醒期间每两小时进行一次认知和主观测试。使用一系列线性混合效应方差分析进行分析。
在SIT条件和ACT条件之间，未观察到间质葡萄糖浓度或认知表现的差异。与ACT条件相比，参与者报告在SIT条件下困倦程度更高，警觉性更低。
在睡眠受限的情况下，打破长时间久坐对葡萄糖代谢没有明显益处。这些发现对行为改变干预有影响。未来的研究需要纳入更大、异质性更低的研究人群和适当的对照条件（即8 - 9小时的睡眠时间）。
