Isacco Laurie, Gimenez Philippe, Ennequin Gaël, Mourot Laurent, Grosprêtre Sidney
Université Clermont Auvergne, CRNH, AME2P, 63000, Clermont-Ferrand, France.
EA3920-Prognostic Markers and Regulatory Factors of Heart and Vascular Diseases, and Exercise Performance, Health, Innovation Platform, Univ. Bourgogne Franche-Comté, Besançon, France.
Eur J Appl Physiol. 2022 Jul;122(7):1727-1739. doi: 10.1007/s00421-022-04954-y. Epub 2022 Apr 27.
To counteract the detrimental health effect of sitting all day long, it has been suggested to regularly break sitting time by standing. However, while the difference in energy expenditure, neuromuscular and/or cardiovascular demand of various postures from lying, sitting, and standing is well documented, little is known regarding the dynamic changes occurring during the sit-to-stand transition itself. The aim of the present study was then to describe the cardiometabolic and neuromuscular responses from sitting to standing and specifically during the time-course of this transition. Twelve healthy young participants were asked to perform standardized raises from sitting posture, while cardiometabolic (cardiorespiratory and hemodynamic variables) and neuromuscular (calf muscles' myoelectrical activity, spinal and supraspinal excitabilities) parameters were monitored. As a result, while there was a rapid adaptation for all the systems after rising, the neuromuscular system displayed the faster adaptation (~ 10 s), then hemodynamic (~ 10 to 20 s) and finally the metabolic variables (~ 30 to 40 s). Oxygen uptake, energy expenditure, ventilation, and heart rate were significantly higher and stroke volume significantly lower during standing period compared to sitting one. In calf muscles, spinal excitability (H-reflexes), was lowered by the sit-to-stand condition, while supraspinal drive (V-wave) was similar, indicating different cortico-spinal balance from sitting to standing. Although very heterogenous among participants in terms of magnitude, the present results showed a rapid adaptation for all the systems after rising and the health benefit, notably in terms of energy expenditure, appears rather modest, even if non negligeable.
为了抵消整天坐着对健康的不利影响，有人建议定期通过站立来中断久坐时间。然而，虽然从躺卧、坐立和站立等各种姿势的能量消耗、神经肌肉和/或心血管需求差异已有充分记录，但对于从坐姿到站姿转换过程中发生的动态变化却知之甚少。因此，本研究的目的是描述从坐姿到站姿，特别是在这个转换过程中的心脏代谢和神经肌肉反应。12名健康的年轻参与者被要求从坐姿进行标准化起身动作，同时监测心脏代谢（心肺和血液动力学变量）和神经肌肉（小腿肌肉的肌电活动、脊髓和脊髓上兴奋性）参数。结果显示，起身后所有系统都有快速适应，其中神经肌肉系统适应最快（约10秒），然后是血液动力学系统（约10至20秒），最后是代谢变量（约30至40秒）。与坐姿相比，站立期间的摄氧量、能量消耗、通气量和心率显著更高，而每搏输出量显著更低。在小腿肌肉中，从坐姿到站姿的转换会降低脊髓兴奋性（H反射），而脊髓上驱动（V波）相似，这表明从坐姿到站姿时皮质脊髓平衡有所不同。尽管参与者之间在幅度上差异很大，但目前的结果显示起身后所有系统都有快速适应，并且健康益处，特别是在能量消耗方面，即使不可忽略，似乎也相当有限。
