A cross-cultural comparison of body composition, physical fitness and physical activity between regional samples of Canadian and English children and adolescents.

OBJECTIVES Cross-cultural comparisons in children's body composition, health-related fitness and physical activity (PA) are rare due to a shortage of comparable data, but such comparisons may help avert worrying global prevalence in childhood obesity, and declining fitness and PA. METHODS We drew samples of Canadian and English children (10 years, n=1630, 50% boys) and adolescents (15 years, n=1406, 56% boys) from three separate, regional studies that conducted comparable school-based assessments (2006-2011). For each age-sex group, we assessed between-country differences for body composition (mass, height, BMI, waist circumference), cardiorespiratory fitness (CRF; 20 m shuttle run test), strength (handgrip) and self-reported PA. We used multiple regression to investigate whether between-country differences in fitness were explained by body composition and PA. RESULTS At any age, Canadian boys and girls were taller, heavier, and had greater BMIs and waist circumferences. English children had higher CRF than Canadians, which was explained by differences in body composition and PA. Canadian children were significantly stronger, partly due to greater body size. There were no between-country differences in adolescent boys. Canadian adolescent girls reported more PA than their English counterparts, but neither PA nor body size explained why Canadian adolescent girls had greater CRF or strength. CONCLUSION Future cross-cultural studies of PA should include indices of growth and fitness to better understand the relationship between intricate differences in PA and health outcomes.