Longitudinal Influence Of Prolonged And Short Bouts Of Sedentary Time On Mental Wellbeing

Abstract

Excessive sedentary time is related to poor mental wellbeing. However, the differential influence of sedentary time accumulated in prolonged versus short bouts on factors related to mental wellbeing is unknown. PURPOSE: To examine the longitudinal influence of sedentary bout length on mood, stress, and sleep over one year. METHODS: Two hundred and seventy healthy adults (48% women; age 27.8 ± 3.7) completed the Profile of Mood States (POMS) and the Perceived Stress Scale (PSS), and wore a Sensewear Armband to objectively measure sedentary time, physical activity, and sleep duration and efficiency at baseline and one year later. Prolonged and short bouts of sedentary time were operationalized to those greater and less than 30 minutes in duration. Fixed effects regression analyses were performed with baseline minutes and changes in prolonged and short bouts of sedentary time and minutes of moderate and vigorous physical activity (MVPA) as predictors of changes in mood disturbance, stress, and sleep duration and efficiency over one year as outcomes. RESULTS: For mood, the overall model was significant (p = 0.04) with changes in prolonged (p = 0.004) and short bouts (p = 0.006) of sedentary time positively predicting changes in mood disturbance. For stress, the overall model trended towards significance (p = 0.06) with only changes in prolonged bouts of sedentary time as a positive predictor (p = 0.003). For sleep duration, the overall model was significant (p < 0.0001) with changes in prolonged and short bouts of sedentary time as inverse predictors and change in MVPA as a positive predictor (all p < 0.0001). For sleep efficiency, the overall model was significant (p < 0.03) with changes in both prolonged (p = 0.017) and short bouts of sedentary time (p = 0.008) as inverse predictors. CONCLUSIONS: Changes in both prolonged and shorter bouts of sedentary time are predictive of future mood, stress, and sleep in healthy young adults adding to the evidence that sedentary time has negative, long-term consequences for wellbeing, regardless of how it is accumulated. Interestingly, in this sample of healthy adults, baseline levels of sedentary time and MVPA were not predictive of changes in mental wellbeing-related outcomes. Interventions targeting sedentary time may not need to target specific bout lengths to realize benefits.