Aerobic fitness of South African school children

Aim. The study aimed to assess the aerobic fitness of adolescents' rural school children and some selected anthropometric predictors of aerobic fitness in the sample. Methods. The nine-minute walk/run test was used to predict the aerobic fitness of 1172 (541 boys and 631 girls) aged 10-16 years, randomly selected in seven schools in two circuits (Mankweng and Toronto) Limpopo province, South Africa. Step-wise regression analysis was used to elucidate the relationship between age, gender and anthropometric variables (as independent variables) and peak oxygen (peak VO2), as a dependent variable. Results. Boys' peak VO2 was significantly higher (P<0.0001) than that of the girls whether expressed in L.min-1 (1.3 +/- 0.24 versus 0.8 +/- 0.11) or mL.kg-1.min-1 (35.2 +/- 15.3 versus 28.7 +/- 14.5). The linear combination of five variables (fat-free mass (FFM), stature, age, body mass and body fat) contributed significantly (F ((5, 1166)) = 154.1, P<0.0001) in predicting peak VO2 among the children, thus accounting for 80% of the variance. Step-wise and multiple regression analysis demonstrated that for boys, a substantial portion of the variance in peak VO2 was explained by FFM, while aerobic fitness variation in girls could be explained substantially by body mass. Conclusion. Boys performed better than girls on aerobic fitness test consistent with most literature concerning gendered dimension of aerobic fitness, which was the function of differences in FFM and body mass of the adolescent children. Greater part of the variance was explained by FFM and body mass for boys and girls, respectively. However, compared to their peers elsewhere, the aerobic performance of our sample is low.