Physical fitness measures among children and adolescents: are they all necessary?

Aim. The aim of this paper was to investigate the relationship among health and skill-related physical fitness variables, and with anthropometric measures in a sample of children and adolescents. Methods. A cross-sectional study was conducted with 526 Brazilian students aged 7-15 years. Physical fitness abilities/skills were assessed through a battery of eight tests: sit-and-reach, standing long jump, 1-minute curl-up, modified pull-up, medicine-ball throw, 9-minute run, 20-meter run and 4 meter shuttle-run. Anthropometric measures considered were weight, height, body mass index (BMI) and wingspan. Analyses included descriptive statistics, Pearson correlations, multiple linear regression and principal component analysis. Results. Anthropometric measures were directly associated between each other. Weight and BMI were negatively associated with the performance in all physical tests requiring propulsion or lifting of the body mass. Direct associations between tests persisted after adjustments for sex, age, type of school and geographic region of school. Conclusion. Results from the principal component analysis evidenced that all physical abilities/motor skills, except flexibility, are strongly associated with each other, suggesting that one test can reflect the overall fitness among youth. Although it is unclear from these analyses which test would be the single choice indicator, previous work on the health impact of cardiorespiratory fitness would suggest that.