Objectively measured patterns of physical activity in primary school children in Coventry: the influence of ethnicity

Aims The aetiology of increased metabolic risk in South Asians is incompletely understood, but may include modifiable factors such as physical activity. This study assessed patterns of physical activity in UK primary school children and examined the influence of ethnicity. Methods We studied a community sample of children aged 8-9 years attending primary schools in Coventry, UK. One hundred and sixty-one children wore combined physical activity and heart rate monitors for 7 days. Levels of activity and energy expenditure were compared between White European (n = 96) and South Asian children (n = 65). Patterns of physical activity during the school week were also described. Results Seventy-three per cent of White Europeans compared with only 35% of South Asians achieved international recommendations of 60 minutes of moderate to vigorous physical activity daily (P < 0.0000). South Asians were less active during the week (106 +/- 28 vs. 120 +/- 32 counts/min, respectively, P = 0.0054) and at weekends (92 +/- 34 vs. 108 +/- 54 counts/min, P = 0.0118) compared with White Europeans. There were differences in energy expenditure with lower physical activity levels in South Asians (daily average 1.68 +/- 0.13 vs. 1.76 +/- 0.17, P < 0.0001). Differences were attributable to less activity after school in South Asians (97 +/- 29 vs. 120 +/- 43 counts/ min, P < 0.0000) as daytime activity was comparable between groups (120 +/- 41 vs. 124 +/- 39 counts/ min, P > 0.05). Conclusion South Asian children in Coventry do significantly less physical activity than White Europeans, mainly attributable to differences in after-school activity. Ethnically tailored interventions should explore whether physical activity can be increased in South Asian children and, if so, whether this increased physical activity improves metabolic health.