Relationships between different nutritional anthropometric statuses and health-related fitness of South African primary school children

Background: A double burden of both under- and over-nutrition exists among South African children. Aim: To describe associations between nutritional statuses and health-related fitness test performances. Subjects and methods: Height and weight of 10 285 children (6–13 years; n = 5604 boys and 4681 girls) were measured and used to calculate body mass index (BMI) and prevalence of overweight and obesity, stunting, wasting and underweight. Physical fitness scores for standing long jump, shuttle run, sit-and-reach, sit-up (EUROFIT) and cricket ball throw were assessed. Age- and gender-specific z-scores were calculated for these variables. Physical fitness for each nutritional status group was compared to children of normal weight. Results: Compared to normal weight children, overweight and obese children scored lower on all fitness tests (p < .001), except cricket ball throw (p = .235) and sit-and-reach (p = .015). Stunted and underweight children performed poorer than normal weight children on most fitness tests (p < .001), except sit-and-reach (stunted: p = .829; underweight: p = .538) and shuttle run (underweight: p = .017). Performance of wasted children was not as highly compromised as other under-nourished groups, but they performed poorer on the cricket ball throw (p < .001). Conclusions: When compared to normal weight children, both under- and over-nourished children performed poorer on some, but not all, health-related fitness tests.