The bidirectional association between sleep and physical activity: A 6.9 years longitudinal analysis of 38,601 UK Biobank participants

Abstract

Although physical activity and sleep may influence each other, little is known about the bidirectional association of these two behaviors. The present analyses included 38,601 UK Biobank participants (51% female, 55.7 ± 7.6 years old, 6.9 ± 2.2 years of follow-up). Physical activity was categorized by the weekly metabolic equivalent of task minutes (highly active: ≥ 1200; active: 600 to <1200; inactive: < 600), and sleep patterns were determined using a composite score of healthy sleep characteristics: morning chronotype, adequate sleep duration (7–8 h/d), never or rare insomnia, never or rare snoring, and infrequent daytime sleepiness. We categorized the sleep score into three patterns (healthy: ≥ 4; intermediate: 2–3; poor: ≤ 1). Multiple logistic regressions examined the association of baseline (or the temporal changes in) sleep/physical activity with physical inactivity/poor sleep at follow-up. Participants with an intermediate or poor sleep pattern at baseline had higher odds (adjusted odds ratio: 1.24 [1.17, 1.32] and 1.65 [1.45, 1.88], respectively) for physical inactivity at follow-up, compared to those with healthy sleep, while shifting to a healthy sleep pattern over time attenuated these adverse associations. Compared to individuals highly active at both time points, being physically inactive at baseline and reducing physical activity over time were both associated with higher odds for poor sleep at follow-up. In conclusion, sleep improvements over time benefitted physical activity at follow-up, while reduced physical activity had a detrimental effect on sleep patterns at follow-up. Our results provide scope for interventions to concurrently target physical activity and sleep.

Introduction

Both poor sleep and physical inactivity are modifiable lifestyle risk factors for non-communicable chronic diseases and mortality.(Piercy et al., 2018; Kwok et al., 2018; Huang et al., n.d.) Although increased physical activity may improve sleep while poor sleep may compromise physical activity through physiological and behavioral pathways, the evidence of the bidirectional associations between physical activity and sleep is sparse and equivocal.(Kline, 2014; Banno et al., 2018; Gerber et al., 2020; Kim et al., 2019; Mesas et al., 2018; Rayward et al., 2018)

Systematic reviews of randomized controlled trials lasting one day to six months in diverse populations suggested that exercise interventions may not improve all sleep characteristics (e.g., sleep duration) in the short term,(Banno et al., 2018; Dolezal et al., 2017) while sleep improvement interventions lasting up to nine months may not increase physical activity.(Kline, 2014) The very few available longitudinal studies were also inconclusive regarding this bidirectional relationship,(Kim et al., 2019; Mesas et al., 2018) and observed different relationships depending on the sleep outcome examined.(Rayward et al., 2018) The heterogeneity of sleep characteristics used in different studies might hinder the interpretation of available literature.(Kwok et al., 2018; Fan et al., 2019)

This study aimed to examine the longitudinal bidirectional association between sleep and physical activity using a repeated examination sub-sample of the UK Biobank.