Abstract
Despite activity guidelines moving towards a 24-h focus, we have a poor understanding of the 24-h activity patterns of adolescents. Therefore, this study aims to describe the 24-h activity patterns of a sample of adolescent females and investigate the association with body mass index (BMI). Adolescent females aged 15–18 years (n = 119) were recruited across 13 schools in 8 locations throughout New Zealand. Actigraph GT3X+ accelerometers were worn 24-h a day for seven days and the output was used to identify time spent in each 24-h component (sleep, sedentary, light-intensity physical activity and moderate-to-vigorous intensity physical activity). In a 24-h period, adolescent females spent approximately half their time sedentary, one third sleeping and the remainder in light-intensity physical activity (15%) and moderate-to-vigorous intensity physical activity (5%). Higher BMI z-scores were associated with 16 min more time spent in light-intensity physical activity. Additionally, those with higher BMI were less likely to meet the sleep and physical activity guidelines for this age group. Compliance with the moderate-to-vigorous intensity physical activity guidelines, sleep guidelines, or both, was low, especially in those classified as overweight or obese. The association between BMI and light activity warrants further investigation.
Highlights
Physical activity research in children and adolescents has traditionally focused on the effects of participation in moderate-to-vigorous physical activity (MVPA), the behavior that accounts for the smallest time proportion of each day, even in those who participate in the highest levels [1]
There was a shift in focus to acknowledge all the movement behaviors in a 24-h period (sleep, sedentary time and light physical activity (LPA) and MVPA) and how these behaviors either alone, or possibly more appropriately, in combination, can affect health [1,3]
Canada developed 24-h movement guidelines for children and youth [3], which were subsequently adopted by countries including New Zealand [4] and Australia [5]
Summary
Physical activity research in children and adolescents has traditionally focused on the effects of participation in moderate-to-vigorous physical activity (MVPA), the behavior that accounts for the smallest time proportion of each day, even in those who participate in the highest levels [1]. There was a shift in focus to acknowledge all the movement behaviors in a 24-h period (sleep, sedentary time and light physical activity (LPA) and MVPA) and how these behaviors either alone, or possibly more appropriately, in combination, can affect health [1,3]. The guidelines recommend children and youth aged 5–17 years should accumulate at least 60 min of MVPA, attain at least 9–11 h sleep (5–13 years) or 8–10 h sleep (14–17 years) and engage in less than two hours sedentary screen-time, each day
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
