This study aimed to examine the associations of both subjectively and objectively measured sleep with physical activity among older adults and to explore the possible moderating role of chronotype in these associations. We included baseline data of 116 community-dwelling older adults without dementia from three prior studies. Pittsburgh Sleep Quality Index and Actigraphy were used as subjective and objective sleep measures, respectively. Physical activity was assessed by the Physical Activity Scale for the Elderly. The Morningness-Eveningness Questionnaire was used to measure chronotype, which was further dichotomized into morning type and non-morning type. Multiple linear regressions were performed to examine the associations, controlling for demographic and health characteristics. We found that better subjective sleep quality, shorter actigraphy sleep duration, and higher actigraphy sleep efficiency were uniquely associated with greater physical activity. Being a morning type might alleviate the adverse association between poor subjective sleep quality and physical activity among older adults.
Keywords: chronotype; objective sleep; physical activity; sleep; subjective sleep.