Background: New Zealand children’s health and fitness performance is declining over time, but whether this change is due to deterioration in all children’s health and fitness performance, or can be attributed to just a certain portion of the population is unknown.
Objectives: To track secular trends and distributional changes in health-and performance-related fitness components among New Zealand primary school children aged 10 to 14 years between 1991 and 2003.
Methods: Health-and performance-related fitness parameters including height, weight, body mass index (BMI), flexibility, standing broad jump, 4 x 9m agility run, abdominal curl-ups, and 550-m run were collected up to twice a year from 3306 children (10-14 years) from one New Zealand school between 1991 and 2003.
Results: Over the twelve year period boys’ weight increased by 4.5 kg (95% confidence limits CL = 2.7-6.2 kg or 0.8% per year) and girls’ by 3.9 kg (CL = 2.0 – 5.9 kg or 0.7% per year). Mean BMI increased by 0.12 kg.m-2 (0.6%) and 0.11 kg.m-2 (0.5%) per year for boys and girls respectively. Children’s 550-m run performance declined by 1.5% and 1.7% per year for boys and girls respectively. Little difference existed between children located in the highest performing and leanest percentiles in 1991 and 2003, but for children in the poorest performing and fattest percentiles, their results were substantially worse in 2003.
Conclusions: These results suggest that the deterioration in the health-and performance-related fitness components of New Zealand 10-14 year-olds is not homogeneous but skewed towards those children who are the heaviest and perform worst in fitness tests.