Cardiorespiratory fitness levels and body composition of adolescent learners from low and middle socioeconomic backgrounds in KwaZulu-Natal province, South Africa

Abstract

Low physical fitness levels, overweight, and obesity directly predict adolescent cardiovascular disease (CVD). Therefore, information about adolescents' health-related fitness from different socioeconomic backgrounds is essential to diagnose CVD risk and determine the need for health and wellness intervention programmes. This study aimed to determine the anthropometric characteristics and cardiorespiratory fitness (CRF) levels of 184 adolescents (girls, n=90; boys, n=94; age range: 13-17 years) from low and middle socioeconomic status backgrounds in KwaZulu-Natal, South Africa. Anthropometric [height, weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR)], and CRF (VȮ2 max from 20 m shuttle run) measurements were taken. Data were analysed using means, standard deviation, percentiles, independent t-test and Wilcoxon test. Pearson correlation measured the association between the dependent and independent variables. Girls’ (35.5%) and boys’ (11.6%) BMIs ranged between the 85th and 97th percentiles. Significant differences were observed for boys' and girls’ WHR and V̇O₂ max (p≤0.05). Controlling for socioeconomic backgrounds, BMI, WHR, and VO₂ max differed significantly (p<0.05). BMI and predicted VO₂ max showed a significant negative correlation for girls (r = -0.25.). In general, adolescent boys had better anthropometric and CRF data than girls, which may predict a healthier status for boys than girls of the same age category and socioeconomic background.