Research article

Correlates of objectively assessed physical activity and sedentary time in children: a cross-sectional study (The European Youth Heart Study)

Andreas Nilsson¹ , Lars Bo Andersen^2,4 , Yngvar Ommundsen³ , Karsten Froberg⁴ , Luis B Sardinha⁵ , Karin Piehl-Aulin¹ and Ulf Ekelund^1,6

¹  School of Health and Medical Sciences, Örebro University, Örebro, Sweden

²  Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway

³  Department of Coaching and Psychology, Norwegian School of Sport Sciences, Oslo, Norway

⁴  Institute of Sports Science & Clinical Biomechanics, University of Southern Denmark, Odense, Denmark

⁵  Faculty of Human Movement, Technical University of Lisbon, Lisbon, Portugal

⁶  MRC Epidemiology Unit, Cambridge, UK

author email corresponding author email

BMC Public Health 2009, 9:322doi:10.1186/1471-2458-9-322

Published:	7 September 2009

Abstract

Background

Identifying leisure time activities performed before and after school that influence time in physical activity (PA) and/or time spent sedentary can provide useful information when designing interventions aimed to promote an active lifestyle in young people. The purpose of this study was to examine associations between mode of transportation to school, outdoor play after school, participation in exercise in clubs, and TV viewing with objectively assessed PA and sedentary behaviour in children.

Methods

A total of 1327 nine- and 15-year-old children from three European countries (Norway, Estonia, Portugal) participated as part of the European Youth Heart Study. PA was measured during two weekdays and two weekend days using the MTI accelerometer, and average percent of time in moderate-to-vigorous PA (MVPA) and time spent sedentary were derived. Potential correlates were assessed by self-report. Independent associations between self-reported correlates with percent time in MVPA and percent time sedentary were analysed by general linear models, adjusted by age, gender, country, measurement period, monitored days and parental socio-economic status.

Results

In 9-year-olds, playing outdoors after school was associated with higher percent time in MVPA (P < 0.01), while participation in sport clubs was associated with higher percent time in MVPA (P < 0.01) in 15-year-olds. No associations with percent time sedentary were observed in either age group.

Conclusion

Frequency of outdoor play after school is a significant correlate for daily time in MVPA in 9-year-olds, while this correlate is attenuated in favour of participation in sport and exercise in clubs in 15-year-olds. Targeting walking to school or reduced TV viewing time in order to increase time in daily MVPA in children is unlikely to be sufficient. Correlates related to time spent sedentary need further examination.