Socio-economic status, growth, physical activity and fitness: The Madeira Growth Study

Abstract

Background: Within a country social conditions change over time and these conditions vary from country to country. The associations between these conditions, somatic growth, physical activity and fitness reflect these changes. Aim: The study documented variation in somatic growth, physical activity and fitness associated with socio-economic status (SES). Subjects and methods: The study involved 507 subjects (256 boys and 251 girls) from the Madeira Growth Study, a mixed longitudinal study of five cohorts (8, 10, 12, 14 and 16 years of age) followed at yearly intervals over 3 years (1996)(1997)(1998). A total of 1493 observations were made. Anthropometric measurements included lengths, body mass, skeletal breadths, girths and skinfolds. Physical activity and SES were collected via questionnaire and interview. Physical fitness was assessed using the Eurofit test battery. Variation in somatic growth, physical activity and physical fitness by SES (high, average and low) was tested with analysis of variance. Results: Significant differences between SES groups were observed for height, body mass and skinfolds. Boys and girls from high SES groups were taller, heavier and fatter (subscapular and triceps skinfolds) than their peers from average and low SES groups. At some age intervals, the high SES group had larger skeletal breadths (girls) and girths (boys and girls) than low SES. Small SES differences were observed for physical activity (sport and leisure-time indices). SES was significantly associated with physical fitness. At some age levels, boys from the low SES group performed better for muscular and aerobic endurance whereas girls from the high SES group performed better for power. Conclusion: Considerable variation in somatic growth and physical fitness in association with SES has been demonstrated, but little association was found for physical activity.

The Relationship between Socioeconomic Status, Family Income, and Measures of Muscular and Cardiorespiratory Fitness in Colombian Schoolchildren

“…The present findings should, however, be interpreted with some caution, because we cannot rule out sample bias as an explanation (Tables II and III). Although we did not observe a clear, direct association between SES and physical fitness in children from Bogotá, as has been shown to some extent, elsewhere, 5,7,27 the present data do suggest that area-level SES may influence fitness to a greater extent than family income. This may be because this is a better indicator of local-area amenities that provide children with the opportunity to develop or maintain fitness via access to safe play areas or sporting infrastructure.…”

“…24,25 Freitas et al 7 reported better Jump performance in girls in the high vs low SES groups but no differences in boys. Using a multifactorial index of SES, Jiminez Pavon et al 5 found that Jump distance increased across children in the low, moderate, and high SES groups, after adjusting for age, height, and adiposity but not sociogeographic factors or potential clustering.…”

“…1,5,7,[21][22][23] The few studies that have attempted to determine how SES interacts with other sociogeographical factors associated with fitness have produced somewhat-contradictory findings. 1,5,7,13 The present results also agree with previous evidence 5 suggesting that SES-related differences in body size can explain at least partly the association between SES and physical fitness.…”

“…Our findings are in contrast with those of Otero et al, 13 who reported that greater SES was associated with lower handgrip in a sample that included both rural and urban Colombian youth. No previous studies, however, have corrected for school-level clustering 6,7 or public/private educational status, both of which made important contributions to our fully adjusted model.…”

“…Again, these factors have not been considered specifically in previous studies of the association between SES and fitness. 5,7,27 Greater cardiorespiratory fitness in private schools may be attributable to superior facilities and students' greater rates of participation in sports and activities, which promote cardiorespiratory fitness, during and after school. Colombian public schools are mandated to provide 2 hours of weekly physical education compared with the 4-6 hours typical of private schools.…”