Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Department of Psychology, University of Southern California, Los Angeles, CA, USA.
Stress. 2021 May;24(3):338-347. doi: 10.1080/10253890.2020.1804852. Epub 2020 Aug 25.
Most children in the United States currently do not meet physical activity (PA) guidelines, and perceived stress is a known barrier against PA. However, most studies have solely focused on the between-subject (BS) association of stress and PA, whereas the within-subject (WS) relationship remains under-studied in children. This limits our understanding of day-level psychosocial factors that influence children's PA engagement. This study assessed the same-day associations of the Morning Cortisol after Awakening (MCA) and morning perceived stress with moderate-to-vigorous physical activity (MVPA) in children using Ecological Momentary Assessment (EMA) methodologies. The analytic sample consisted of 143 children from Los Angeles in the Mothers and Their Children's Health (MATCH) study. Children collected four saliva samples and wore accelerometers to assess MVPA minutes across four days (two weekdays and two weekend days) during each data collection wave. On weekend days, they also answered a mobile phone EMA survey on perceived stress within 1 h of awakening. Data from four assessment waves, each approximately six months apart, were combined and analyzed cross-sectionally. Multilevel modeling, which adjusts for the nested data structure, was used to test the same-day associations of MCA and weekend morning perceived stress with MVPA. On weekend days when morning perceived stress was higher than usual, participants engaged in more MVPA on the same day (β = 0.79, SE = 0.32, = 0.02), but no association was found between MCA and MVPA. These findings elucidate same-day factors that predict MVPA in children and inform future WS studies on stress and PA.HighlightIt is unknown how stress influences children's daily activity levels. We tested if two types of stress (self-reported and saliva-measured) are related to children's daily activity. We found that self-reported stress is associated with physical activity, but saliva-measured stress is not.
大多数美国儿童目前不符合身体活动 (PA) 指南，而感知到的压力是阻碍 PA 的已知因素。然而，大多数研究仅关注压力和 PA 之间的个体差异（BS）关联，而儿童的个体差异（WS）关系仍未得到充分研究。这限制了我们对影响儿童 PA 参与的日间心理社会因素的理解。本研究使用生态瞬时评估 (EMA) 方法评估了儿童在同一天内清晨皮质醇后觉醒（MCA）和早晨感知压力与中等到剧烈体力活动（MVPA）之间的关联。分析样本包括来自洛杉矶母亲及其子女健康研究（MATCH）的 143 名儿童。儿童在四个数据收集波次中，每天收集四个唾液样本并佩戴加速度计以评估 MVPA 分钟数，每次数据收集波次跨越四天（两个工作日和两个周末日）。在周末，他们还在唤醒后 1 小时内通过移动电话 EMA 调查回答感知压力问题。将来自四个评估波次的数据结合起来进行横断面分析，每个波次大约相隔六个月。多层次模型用于测试 MCA 和周末早晨感知压力与 MVPA 的当天关联，该模型可调整嵌套数据结构。在周末感知压力高于平时的日子里，参与者在同一天进行了更多的 MVPA（β=0.79，SE=0.32，=0.02），但 MCA 与 MVPA 之间没有关联。这些发现阐明了预测儿童 MVPA 的当天因素，并为未来关于压力和 PA 的 WS 研究提供了信息。
重点：
目前尚不清楚压力如何影响儿童的日常活动水平。我们测试了两种类型的压力（自我报告和唾液测量）是否与儿童的日常活动有关。我们发现，自我报告的压力与体力活动有关，但唾液测量的压力与体力活动无关。
