Abstract
Background: Physical activity (PA), specifically moderate-to-vigorous PA (MVPA), is associated with better health outcomes in adolescents. Active commuting to school, participating in organised sport and physical education (PE) have been shown to increase adolescents’ daily levels of PA, but have never been investigated in a nationwide cohort in New Zealand. Having a better understanding of how these domains of PA influence overall PA can better inform future interventions in adolescents.
Objective: To investigate the patterns of PA in a sample of adolescent females in New Zealand. In particular this thesis will describe how active commuting, participation in organised sport and participation in school PE contribute to the total amount of light PA (LPA) and MVPA accumulated over a 24 h day.
Methods: This sample included 114 female adolescents, aged 15-18 years, from the 2019 SuNDiAL study. Participants completed a Dietary Habits, Motivations, Attitudes and Beliefs questionnaire online, which included questions about each PA domain of interest: mode of active transport, participation in sport and participation in PE. PA was measured using ActiGraph accelerometers worn continuously for seven days.
Results: On average, participants spent 437 min/d (7 h 17 min) sleeping, 711 min/d (11 h 51 min) in sedentary time, 220 min/d (3 h 40 min) in LPA and 42 min/d in MVPA. Twenty four percent of participants met PA guidelines. Sixty eight percent participated in organised sport and accumulated, on average, an additional 46 min/d (95% CI 17.8 to 74.5) of LPA and 17 min/d (95% CI 8.5 to 24.5) of MVPA compared to those who did not. Thirty six percent participated in PE and accumulated, on average, an additional 37 min/d (95% CI 7.7 to 65.9) of LPA and 7 min/d (95% CI -1.7 to 16.4) of MVPA compared to those who did not. Twenty one percent used active transport, and accumulated, on average 11 min/d (95% CI -51.3 to 30.1) less LPA and an additional 12 min/d (95% CI -0.3 to 24.1) of MVPA compared to those who did not. In the hour directly before and after school, compared to those that used motorised transport, those that actively commuted accumulated an additional, 5 min/d (95% CI 1.4 to 8.6) of MVPA before school, and 4 min/d (0.6 to 6.9) respectively. Participants who participated in one, two or three PA domains of interest accumulated an additional 11 min/d, 15 min/d and 35 min/d of MVPA respectively.
Conclusion: Findings from this study confirm that majority of female adolescents are not meeting PA guidelines. Furthermore, active transport and participation in organised sport and/or PE result in meaningful increases in LPA and MVPA, with the greatest difference seen for those that participate in organised sport. For every additional PA domain of interest, time spent in MVPA was increased, suggesting that a combination of PA domains is an important concept to consider when targeting engagement in PA for adolescent females.