Variation in physical fitness between ethnic groups in nine year olds

Background There is little information on cardio-respiratory fitness of chi ldren, especially in ethnic minorities in Britain. In this study we assess the associations of social factors, ethnicity, parental health related fact ors, child's anthropometry, blood pressure and cholesterol measurements wit h cardio-respiratory fitness. Methods Power output against load at 85% of the maximum heart rate (PWC85%) , was measured, using a cycle-ergometer test, in children aged 8-9 years in 22 randomly selected areas in England, 14 in Scotland and in 20 inner city areas in England: The subjects were 317 boys and 310 girls from the Englis h sample, 152 boys and 140 girls from the Scottish sample and 242 boys and 261 girls from the inner city sample. Results Short stature (P < 0.001), fatness (P < 0.001), and Indian subconti nent origin (OR = 0.34, 95% CI:0.16, 0.68 in boys and OR = 0.22, 95% CI:0.1 2, 0.40 in girls) were associated with inability to finish the test. In tho se who finished the test PWC85% was greater in taller children and in those with lower skinfold values (P < 0.001, except height in boys P = 0.017). T he PWC85% in those originating in the Indian continent was lower (-0.17 wat t/kg, 95% CI:-0.32, -0.01 in boys and -0.29, 95% CI:-0.43, -0.14 in girls) than in white children. Conclusions Shorter and obese children have poorer physical fitness than ot her children. Physical fitness is lower in children originating in the Indi an subcontinent than other British children. This seems to be unrelated to socioeconomic disadvantage. Physical inactivity and lack of cycling skills may explain our findings.