Isotemporal substitution analysis of time between sedentary behavior, and physical activity on sleep quality in younger adults: a multicenter study.

objectiveTo evaluate the effects of replacing time spent in sedentary behavior (SB) with moderate to vigorous physical activity on sleep quality in young adults.

methodsMulticenter cross-sectional study, carried out with students enrolled in undergraduate courses at universities in Brazil. Sleep quality was assessed using a question of the World Health Organization Quality of Life (WHOQOL-brief) and classified as good or poor sleep quality. SB was evaluated by self-reported total sitting time, and the level of leisure-time PA was classified according to the intensity of moderate-intensity physical activity (MPA) and vigorous-intensity physical activity (VPA), which were assessed using a self-reported questionnaire. An isotemporal replacement logistic model was used to evaluate the effects of different SB, MPA, and VPA sessions on sleep quality.

resultsA total of 8,059 study participants were evaluated, the majority had poor sleep quality (64.79%), were physically inactive (48.28%, defined as practicing < 150 min of MPA or < 75 min of VPA per week), and spent ≥ 9 h/day in SB (55.08%). The multivariate model showed an association between non-adherence to wake-based movement guidelines and poor sleep quality, where those with one altered behavior were 43% more likely to have poor sleep quality (OR:1.43;95%CI:1.27 to 1.60), while individuals with two altered behaviors were 97% more likely (OR:1.97;95%CI:1.73 to 2.24). In the isotemporal analysis, replacing MPA and VPA with equivalent time in SB increased the odds of poor sleep at all times assessed, with peaks of 56% for MPA and 68% for VPA.

conclusionThe results of the present study indicate that replacing SB with the same amount of MPA or VPA may reduce poor sleep quality.