Sleep As a Moderator of the Relationship between Exercise and Mood

Introduction: Poor self-reported sleep quality is related to decreased positive emotions the next day (McCrae et al., 2008). Additionally, short sleep duration is associated with increased risk of depressive symptoms (Matsushita, Koyama, Ushijima, et al., 2014). A meta-analysis found that engaging in moderate and vigorous physical activity can help improve total sleep time and quality of sleep (Youngstedt, O’Connor, et al., 1997). A daily diary study looked at sleep quality as a moderator of physical activity and mood (Hyde, Conroy, Pincus, & Ran, 2011), but didn’t find that sleep quality accounted for associations between physical activity and pleasant mood. This study explores the relationship between sleep satisfaction and mood, and sleep duration and mood. It also explores whether sleep duration or sleep satisfaction moderate the relationship between affect and different types of exercise.

Methods: 104 undergraduate psychology students from a Mid-Atlantic public university completed the study for course credit. For 21 consecutive days, participants completed 10- to 15-minute Qualtrics surveys on their phone or laptop about their health behaviors and psychological well-being.

Results: There was a significant relationship from moderate exercise to sleep satisfaction (y₁₀= 0.001313; t=3.181; p=0.002), such that the amount of moderate exercise on a given day predicted how satisfied an individual was with their amount of sleep that same night. Sleep satisfaction was also a significant moderator of the relationship between previous day vigorous exercise and positive mood the next day (y₃₀= 0.003082; t=2.146; p=0.034), meaning that that those with a higher level of sleep satisfaction had a stronger vigorous exercise to positive mood relationship.

Conclusions: These findings suggest that moderate exercise, in particular, is beneficial for improving satisfaction with sleep. Thus, moderate exercise may be beneficial for individuals who have poor quality sleep. Additionally, sleep satisfaction is a moderator of the relationship between vigorous exercise and positive mood, which suggests the importance of satisfaction with sleep in obtaining mood benefits from exercise.