Abstract
This study examined the temporal effects of mood and physical activity on subsequent night sleep quality and investigated the differences between objective and subjective sleep measures. Using a within-subject daily process method, 112 participants (81.3% female, mean age = 21.91 years) monitored their mood, physical activity, and sleep over seven days in natural environments. Mood was self-reported using mood diary, while physical activity was recorded via actigraphy (Philips AW2). Sleep quality _ total sleep time (TST), sleep efficiency (SE), sleep onset latency (SOL), and sleep quality rating _ was measured using actigraphy and sleep diary. Participants also completed questionnaires on demographics, Insomnia Severity Index, Pittsburgh Sleep Quality Index, and Global Physical Activity Questionnaire. Multilevel modeling of 784 observations revealed that physical activity, mood disturbance, and overall mood rating did not predict TST, SE, and SOL measured using actigraphy. However, sleep diary data indicated that mood disturbance significantly predicted TST (p = .004), SE (p < .001), and sleep quality rating (p < .001), while overall mood rating significantly predicted TST (p = .022) and sleep quality rating (p < .001). Physical activity also significantly predicted TST (p = .041), SE (p = .001), SOL (p = .006), and sleep quality rating (p = .024) assessed by sleep diary. A paired sample t-test revealed discrepancies between actigraphy and sleep diary measurements of TST (t(111) = -4.96, p < .05), SE (t(111) = -4.47, p < .05), and SOL (t(111) = 2.59, p < .05). In conclusion, lower mood disturbance and higher physical activity level significantly improve subsequent night sleep quality. Addressing mood and promoting regular physical activity are key strategies for improving sleep quality. Early screening for mood and sleep problems, combined with personalized interventions, could yield long-term benefits and improve overall well-being.