The Enivronment and Children's Physical Activity: The PEACH Project

Introduction The PEACH project (Personal and Environmental Associations with Children’s Health: www.bris.ac.uk/enhs/peach) is a longitudinal study investigating the environmental and personal determinants of physical activity and eating behaviours in children across the transition from primary to secondary school. A cohort of 1307 final year primary school children was initially recruited from 23 UK primary schools (Year 6: aged 11.0 ± 0.4yrs) and 953 of these were followed up one year later in their first year of secondary school (Year 7: aged 12.0 ± 0.4yrs).

Methods Weekly physical activity was measured by accelerometry (Actigraph GT1M) and children wore a GPS receiver (Garmin Foretrex 201) after school to objectively record activity in different locations. Accelerometer and GPS data were recorded at 10 second epochs and were date and time matched to describe patterns of physical activity when both a GPS and accelerometer record were present (outdoors) and when there was accelerometer data only (indoors). Height (m) was measured with a stadiometer and weight (kg) was measured using digital scales (SECA), with children wearing indoor clothing, and shoes removed. Self reported determinants of physical activity including perceptions of the environment were measured via a computerised questionnaire.

Results Compared to primary school, levels of active commuting, the proportion of young people consuming 5 portions of fruit and vegetables and the numbers eating breakfast everyday were lower at secondary school. Results of combined GPS and accelerometer data indicate that children gain more activity on their journey to school than in the school playground when they arrive and overall children recorded 41.7 ± 46.1 minutes outdoors between 3.30 pm and 8.30 pm. Children were up to 2.5 times more active outdoors than indoors (1345.8 ± 907.3 vs 508.9 ± 282.9 counts per minute). Children were also 5 times more active outside in green space compared to time spent indoors, but only 2% of monitored time was spent in green space, the majority of their time outside was not spent in green space. There was no gender difference in time spent outdoors. The most consistent determinant of physical activity was ‘independent mobility’, the reported frequency children were allowed to go to different destinations unsupervised by adults. Combined physical activity and sedentary data also indicated that watching TV or playing computer games for more than 2 hours a day was related to greater psychological difficulties irrespective of how active the children were.

Discussion PEACH is the largest data set to include both objectively measured location and physical activity. It is already providing important evidence that along with the social environment, both the built environment and green space matter for children’s physical activity. The transition form primary to secondary school is a pivotal for the decline in activity and diet related health behaviours. The PEACH Project is funded by the National Prevention Research Initiative and the World Cancer Research Fund.