Specific physical activities, sedentary behaviours and sleep as long-term predictors of objectively measured physical activity in 91,653 adults: A prospective cohort study

Abstract

Objective: The evidence for the prospective relationships between specific physical activities (PA), sedentary behaviours (SB) and sleep on subsequent total PA levels is scarce. The purpose of this study was to examine prospective associations between self-reported PA, SB and sleep, and changes in these with subsequent objectively measured PA. Methods: A sub-sample of 91,653 UK Biobank participants reported moderate-to-vigorous PA (MVPA), lifestyle activities, TV viewing, computer use and sleep throughscreen-based questionnaires at baseline (2006-2010), and provided valid accelerometry data (dominant wrist-worn for 7 days between 2013 and 2015). A further sub-sample of 7,709 participants repeated the screen-based questionnaires between 2012 and 2013. Results: In both women (n=51,548) and men (n=40,105), positive associations were observed between all self-reported measures of PA at baseline (MVPA, lifestyle/job-related activities, active transporting modes) and objectively measured PA levels at follow-up (median 5.7 years); an exception was 'walking/standing at work' in women. Sedentary time at work, TV viewing and computer use were inversely associated with PA at follow-up. Sleeping either more or less than 7 hours/day at baseline was associated with lower PA at follow-up (except for £6 hours/day in men). In the repeat self-report sub-sample (median 4.3 years), relatively higher physical activity at follow-up was observed in those who maintained or achieved favourable levels of MVPA, walking for pleasure, strenuous sports, other exercises, heavy DIY (in women), heavy physical work, and walking/standing at work (in women), sedentary time at work, getting about methods, commuting methods (in women), TV viewing, computer use or sleep.Conclusions: Initial levels of PA, SB and sleep, and changes in these variables were generally associated with subsequent objectively measured PA in the expected directions, suggesting these specific behaviours all contribute to total volume of physical activity over time and could thus be targets for intervention.