%0 Journal Article %T Cross-sectional study of ethnic differences in physical fitness among children of South Asian, black African每Caribbean and white European origin: the Child Heart and Health Study in England (CHASE) %A A R Rudnicka %A A S Donin %A C G Owen %A C M Nightingale %A D G Cook %A K L Westgate %A P H Whincup %A S Brage %A S R Kerry %A U Ekelund %J - %D 2016 %R 10.1136/bmjopen-2016-011131 %X Objective Little is known about levels of physical fitness in children from different ethnic groups in the UK. We therefore studied physical fitness in UK children (aged 9每10ˋyears) of South Asian, black African每Caribbean and white European origin. Design Cross-sectional study. Setting Primary schools in the UK. Participants 1625 children (aged 9每10ˋyears) of South Asian, black African每Caribbean and white European origin in the UK studied between 2006 and 2007. Outcome measures A step test assessed submaximal physical fitness from which estimated VO2 max was derived. Ethnic differences in estimated VO2 max were estimated using multilevel linear regression allowing for clustering at school level and adjusting for age, sex and month as fixed effects. Results The study response rate was 63%. In adjusted analyses, boys had higher levels of estimated VO2 max than girls (mean difference 3.06ˋmL O2/min/kg, 95% CI 2.66 to 3.47, p<0.0001). Levels of estimated VO2 max were lower in South Asians than those in white Europeans (mean difference ˋ0.79ˋmL O2/min/kg, 95% CI ˋ1.41 to ˋ0.18, p=0.01); levels of estimated VO2 max in black African每Caribbeans were higher than those in white Europeans (mean difference 0.60ˋmL O2/min/kg, 95% CI 0.02 to 1.17, p=0.04); these patterns were similar in boys and girls. The lower estimated VO2 max in South Asians, compared to white Europeans, was consistent among Indian, Pakistani and Bangladeshi children and was attenuated by 78% after adjustment for objectively measured physical activity (average daily steps). Conclusions South Asian children have lower levels of physical fitness than white Europeans and black African每Caribbeans in the UK. This ethnic difference in physical fitness is at least partly explained by ethnic differences in physical activity %U https://bmjopen.bmj.com/content/6/6/e011131