School of Kinesiology, Shanghai University of Sport, Shanghai, CHINA.
Med Sci Sports Exerc. 2020 Apr;52(4):851-858. doi: 10.1249/MSS.0000000000002212.
This study aimed to determine whether interrupting prolonged sitting with three different walking-bout schedules improves glycemic metabolism relative to continuous prolonged sitting in sedentary adults.
In a randomized, crossover trial, 16 inactive healthy adults (7 men, 24 ± 3 yr old) completed four 26-h laboratory sessions, including 22.5 h in an energy expenditure (EE)-testing calorimeter chamber. The four 9-h intervention periods were as follows: 9-h uninterrupted sitting (SIT), 30-min sitting/3-min brisk (60% V˙O2max) treadmill walk (WALK3), 45-min sitting/5-min (WALK5), or 60-min sitting/8-min (WALK8). Coprimary outcomes included the difference in the mean interstitial glucose concentration, total area under the curve (tAUC), and incremental area under the curve (iAUC) for the entire 26 and 9 h (intervention period) during three activity-bout conditions compared with SIT.
Compared with SIT, the 26-h mean glucose concentration was attenuated in WALK8 (Δmean -0.22 mmol·L [95% confidence interval = -0.43 to -0.001], P = 0.048) without adjustment for EE and attenuated in WALK3 (Δ-0.47 mmol·L [-0.75 to -0.10]), WALK5 (Δ-0.47 mmol·L [-0.83 to -0.10]), and WALK8 (Δ-0.53 mmol·L [-0.92 to -0.13]) after adjustment for EE (all P < 0.01). The 26-h tAUC was reduced in WALK3 (Δ-11.18 mmol·L per 26 h [-20.07 to -2.29]), WALK5 (2.12.67 mmol·L per 26 h [-22.54 to -2.79]), and WALK8 (Δ-13.85 mmol·L per 26 h [-24.60 to -3.10]) (all P < 0.01), as well as the iAUC (all P < 0.05), only after adjustment for EE. The 9-h mean glucose concentration, tAUC, and iAUC decreased in the three activity-break conditions regardless of EE adjustment (all P < 0.05).
All three walking-bout conditions improved glycemic metabolism compared with SIT, independent of EE, in inactive, healthy adults.
本研究旨在确定与连续久坐相比，三种不同的短暂步行活动打断长时间久坐是否能改善久坐成年人的血糖代谢。
在一项随机交叉试验中，16 名不活跃的健康成年人（7 名男性，24 ± 3 岁）完成了 4 个 26 小时的实验室试验，其中包括 22.5 小时在能量消耗（EE）测试热量计室中。四个 9 小时的干预期如下：9 小时不间断坐姿（SIT）、30 分钟坐姿/3 分钟快走（60% V˙O2max）跑步机行走（WALK3）、45 分钟坐姿/5 分钟（WALK5）或 60 分钟坐姿/8 分钟（WALK8）。主要结局指标包括与 SIT 相比，在三种活动间断条件下，整个 26 小时和 9 小时（干预期）的平均间质葡萄糖浓度、总曲线下面积（tAUC）和增量曲线下面积（iAUC）的差异。
与 SIT 相比，WALK8 组 26 小时平均血糖浓度降低（Δmean -0.22 mmol·L [95%置信区间=-0.43 至 -0.001]，P = 0.048），而无需调整 EE，WALK3（Δ-0.47 mmol·L [-0.75 至 -0.10]）、WALK5（Δ-0.47 mmol·L [-0.83 至 -0.10]）和 WALK8（Δ-0.53 mmol·L [-0.92 至 -0.13]）在调整 EE 后降低（均 P < 0.01）。WALK3（Δ-11.18 mmol·L per 26 h [-20.07 至 -2.29]）、WALK5（2.12.67 mmol·L per 26 h [-22.54 至 -2.79]）和 WALK8（Δ-13.85 mmol·L per 26 h [-24.60 至 -3.10]）（均 P < 0.01）以及 iAUC（均 P < 0.05）在调整 EE 后也有所降低，仅在调整 EE 后，9 小时的平均血糖浓度、tAUC 和 iAUC 在三种活动中断条件下均降低（均 P < 0.05）。
在不活跃的健康成年人中，与 SIT 相比，所有三种短暂步行活动都能改善血糖代谢，与 EE 无关。
