Relationships of physical activity and sedentary behaviour with the previous and subsequent nights’ sleep in children and youth: A systematic review and meta‐analysis

<jats:title>Summary</jats:title><jats:p>The interrelationships between sleep and daytime movement behaviours have been examined at interindividual level. Studies of within‐person, temporal relationships of daytime physical activity (PA) and sedentary behaviour with the previous and subsequent nights’ sleep are increasing. The present systematic review and meta‐analysis synthesised the results of studies in school‐aged children and youth. Eight databases (MEDLINE, PsycINFO, EMBASE, Global Health, PubMed, Web of Science, SPORTDiscus, and CINAHL) were searched for peer‐reviewed articles that examined the association between daytime movement behaviours (including PA, sedentary time, or sedentary recreational screen time) and night‐time sleep on the same day, or the association between night‐time sleep and daytime movement behaviours the next day, in children and youth. A total of 11 studies comprising 9,622 children and youth aged 5–15 years met the inclusion criteria. Sedentary time was negatively associated with the subsequent night’s sleep duration (<jats:italic>r</jats:italic> = −0.12, 95% confidence interval −0.23 to −0.00; <jats:italic>I</jats:italic><jats:sup>2</jats:sup> = 93%; <jats:italic>p</jats:italic> = .04). Positive relationships between PA and the previous or subsequent night’s sleep duration were observed only for studies that adjusted for accelerometer wear time. There was some evidence suggesting that a longer sleep duration was associated with less sedentary time and a higher proportion of the daytime spent being physically active and vice versa, although the association was weak and based on a limited number of studies. From a clinical perspective, promotion of either sleep hygiene or daytime PA should be planned with considerations of the virtuous or vicious circle between these behaviours and monitor concurrent effects on the others.</jats:p>