Abstract

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, p = 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.

• Highlight

• It 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.

摘要

美国的大多数儿童目前不符合体育活动 (PA) 指南，而感知压力是对抗 PA 的已知障碍。然而，大多数研究仅关注压力和 PA 的主体间 (BS) 关联，而儿童中的主体内 (WS) 关系仍未得到充分研究。这限制了我们对影响儿童 PA 参与的日常社会心理因素的理解。本研究使用生态瞬时评估 (EMA) 方法评估了儿童觉醒后早晨皮质醇 (MCA) 和早晨感知压力与中度至剧烈体力活动 (MVPA) 的当天关联。分析样本包括来自洛杉矶的 143 名母亲及其子女健康 (MATCH) 研究中的儿童。在每个数据收集波期间，儿童收集了四个唾液样本并佩戴加速度计来评估四天（两个工作日和两个周末）的 MVPA 分钟数。在周末的日子里，他们还回答了一项关于醒来后 1 小时内感知压力的手机 EMA 调查。将来自四个评估波的数据（每波相隔大约六个月）进行组合和横断面分析。针对嵌套数据结构进行调整的多级建模用于测试 MCA 和周末早晨感知压力与 MVPA 的同一天关联。在早晨感知压力高于平时的周末，参与者在同一天参与了更多的 MVPA（β = 0.79，SE = 0.32，他们还回答了一项关于醒来后 1 小时内感知压力的手机 EMA 调查。将来自四个评估波的数据（每波相隔大约六个月）进行组合和横断面分析。针对嵌套数据结构进行调整的多级建模用于测试 MCA 和周末早晨感知压力与 MVPA 的同一天关联。在早晨感知压力高于平时的周末，参与者在同一天参与了更多的 MVPA（β = 0.79，SE = 0.32，他们还回答了一项关于醒来后 1 小时内感知压力的手机 EMA 调查。将来自四个评估波的数据（每波相隔大约六个月）进行组合和横断面分析。针对嵌套数据结构进行调整的多级建模用于测试 MCA 和周末早晨感知压力与 MVPA 的同一天关联。在早晨感知压力高于平时的周末，参与者在同一天参与了更多的 MVPA（β = 0.79，SE = 0.32，p  = 0.02），但没有发现 MCA 和 MVPA 之间存在关联。这些发现阐明了预测儿童 MVPA 的当天因素，并为未来的 WS 压力和 PA 研究提供信息。

• 强调

• 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身体活动有关，但唾液测量的压力与此无关。