Heiland Emerald G, Tarassova Olga, Fernström Maria, English Coralie, Ekblom Örjan, Ekblom Maria M
Department of Physical Activity and Health, The Swedish School of Sport and Health Sciences (GIH), Stockholm, Sweden.
Department of Physiology, Nutrition, and Biomechanics, The Swedish School of Sport and Health Sciences (GIH), Stockholm, Sweden.
Front Hum Neurosci. 2021 Sep 16;15:719509. doi: 10.3389/fnhum.2021.719509. eCollection 2021.
Prolonged sitting is increasingly common and may possibly be unfavorable for cognitive function and mood. In this randomized crossover study, the effects of frequent, short physical activity breaks during prolonged sitting on cognitive task-related activation of the prefrontal cortex were investigated. The effects on working memory, psychological factors, and blood glucose were also examined, and whether arterial stiffness moderated prefrontal cortex activation. Thirteen subjects (mean age 50.5 years; eight men) underwent three 3-h sitting conditions, interrupted every 30-min by a different 3-min break on separate, randomized-ordered days: seated social interactions (SOCIAL), walking (WALK), or simple resistance activities (SRA). Arterial stiffness was assessed at baseline. Before and after each 3-h condition, psychological factors (stress, mood, sleepiness, and alertness) were assessed through questionnaires and functional near-infrared spectroscopy (fNIRS) was used to measure changes in prefrontal oxygenated hemoglobin (Oxy-Hb), indicative of cortical activation, while performing working memory tasks [1- (baseline), 2-, and 3-back]. Blood glucose levels were continuously measured throughout the conditions. Results revealed no significant changes in Oxy-Hb during the 2-back compared with the 1-back test in any condition, and no time-by-condition interactions. During the 3-back test, there was a significant decrease in Oxy-Hb compared with the 1-back after the WALK condition in the right prefrontal cortex, but there were no time-by-condition interactions, although 3-back reaction time improved only in the WALK condition. Mood and alertness improved after the WALK condition, which was significantly different from the SOCIAL condition. Arterial stiffness moderated the effects, such that changes in Oxy-Hb were significantly different between WALK and SOCIAL conditions only among those with low arterial stiffness. Blood glucose during the interventions did not differ between conditions. Thus, breaking up prolonged sitting with frequent, short physical activity breaks may reduce right prefrontal cortex activation, with improvements in some aspects of working memory, mood, and alertness. www.ClinicalTrials.gov, identifier NCT04137211.
长时间坐着的情况越来越普遍，而且可能对认知功能和情绪不利。在这项随机交叉研究中，我们调查了长时间坐着期间频繁进行短暂身体活动休息对前额叶皮质与认知任务相关的激活的影响。还研究了对工作记忆、心理因素和血糖的影响，以及动脉僵硬度是否调节前额叶皮质的激活。13名受试者（平均年龄50.5岁；8名男性）经历了三种3小时的坐姿条件，在不同的随机顺序的日子里，每30分钟被不同的3分钟休息打断：坐着进行社交互动（SOCIAL）、步行（WALK）或简单的阻力活动（SRA）。在基线时评估动脉僵硬度。在每种3小时条件前后，通过问卷评估心理因素（压力、情绪、困倦和警觉性），并使用功能近红外光谱（fNIRS）测量在执行工作记忆任务[1-（基线）、2-和3-back]时前额叶氧化血红蛋白（Oxy-Hb）的变化，这表明皮质激活。在整个过程中持续测量血糖水平。结果显示，在任何条件下，与1-back测试相比，2-back测试期间Oxy-Hb没有显著变化，也没有时间与条件的交互作用。在3-back测试中，与1-back相比，WALK条件后右侧前额叶皮质的Oxy-Hb显著降低，但没有时间与条件的交互作用，尽管只有在WALK条件下3-back反应时间有所改善。WALK条件后情绪和警觉性有所改善，这与SOCIAL条件有显著差异。动脉僵硬度调节了这些影响，使得只有在动脉僵硬度较低的人群中，WALK和SOCIAL条件之间Oxy-Hb的变化才有显著差异。干预期间不同条件下的血糖没有差异。因此，用频繁的短暂身体活动休息来打破长时间坐着的状态，可能会减少右侧前额叶皮质的激活，并改善工作记忆、情绪和警觉性的某些方面。ClinicalTrials.gov，标识符NCT04137211。
