Cardiorespiratory endurance (CRE) is an important health marker. The aim of this study was to examine temporal trends of CRE performance for Italian children between 1984 and 2010. Using a repeated cross-sectional study design, 5303 CRE test results were available for 2520 children aged 11-13 years from a single Northern Italian middle-high school between 1984 and 2010. CRE was measured as 1000-m and 12-min run test performance. With adjustments for BMI, temporal trends in means were estimated using linear regression, with trends in distributional characteristics described visually and estimated as the ratio of coefficients of variation (CVs). There was a significant small increase in BMI (effect size (ES) [95%CI]: 0.40 [0.32, 0.48]) over the entire period. When adjusted for BMI, there were significant small to moderate declines in mean running speed (ES [95%CI]: 1000-m, - 0.34 [-0.39, - 0.29]); 12-min, - 0.65 [-0.70, - 0.60]). Declines were larger for boys compared to girls. Variability substantially increased over time (ratio of CVs: range, 1.7-2.9), with larger declines in children with low running speed compared to children with average or high running speed. Our findings may be important to public health because low CRE is significantly related to current and future health.
Keywords: Cardiorespiratory fitness; body mass index; child; public health; running; secular trend.