The prevalence of childhood obesity is increasing in New Zealand. Since 2004, Sport Waikato has delivered Project Energize, a through-school nutrition and physical activity program, to primary schools in the Waikato. Energize is funded by the Waikato District Health Board. We have previously shown that obesity measures of body mass index, waist-to-height ratio and percentage body fat are negatively associated with the time taken to run 550m, T550. The aim was to compare T550 in 2015 with the 2011 T550 reference derived from the T550 from 5076 Waikato children in the 2011 evaluation of Energize
In 2015 in a representative sample of children by age, gender, socioeconomic status and ethnicity (n=5784) T550 was measured following the 2011 protocol. The Z-score for every child in the 2011 and 2015 evaluations were derived and differences in T550 between 2011 and 2015 determined using ANOVA.
In 2015 overall children ran 550m faster than in 2011. In particular, run times in 2015 for boys were significantly faster than in 2011 (Z-score mean difference -0.12,95% CI -0.166, -0.077) and for ages 7, 8 and 9 years.
In a climate of increasing childhood obesity in New Zealand, the decrease in time to run 550m confirms that Project Energize continues to be effective. This information can be used to inform and evaluate future interventions to tackle obesity in school children.