Outdoor time, physical activity and sedentary time among young children: The 2012–2013 Canadian Health Measures Survey

OBJECTIVES: Previous studies have shown that children who spend more time outdoors are more active and spend less time sedentary, but these studies were limited by the use of small convenience samples. We examined the relationship between outdoor time and measures of physical activity (PA), screen time and sedentary time in a nationally-representative sample of young children. METHODS: Parental reports of outdoor time were obtained for 594 children aged 3–6 years (47.8% girls) who participated in the 2012–2013 Canadian Health Measures Survey. Participants were asked to wear an Actical accelerometer for seven consecutive days. Outdoor time and screen time were assessed by parent reports. The relationships between outdoor time and measures of PA, screen time and sedentary time were examined with linear regression models. Adherence to PA guidelines was estimated based on a betabinomial distribution, and adherence with the screen time guidelines was assessed through logistic regression models. All analyses were stratified by age group (3–4 and 5–6 year olds) and adjusted for sex, parental education and household income. RESULTS: Among 5–6 year olds, each additional hour spent outdoors was associated with an additional 10 minutes of moderate-to-vigorous PA (95% CI: 6–14), 27,455 more accelerometer counts/day (95% CI: 11,929–42,980) and an increased likelihood of meeting the PA guidelines (OR = 2.53; 95% CI: 1.68–3.82). No significant relationships were observed among 3–4 year olds. CONCLUSION: Outdoor time has a large effect on PA among 5–6 year olds at a population level. Future studies should examine the correlates of outdoor time to inform novel PA promotion interventions.