Linear and nonlinear relationships between body mass index and physical fitness in Brazilian children and adolescents

Objectives The purpose of this study was to evaluate the linear and curvilinear relationship between body mass index (BMI) and physical fitness in children and adolescents. Methods Participants were 4567 (2505 girls) children aged 6–16 years. Weight and height were measured and BMI was calculated and adjusted for age and sex using WHO z‐scores. Physical fitness was evaluated with the following tests: Yo‐Yo test, standing long jump, seated 2‐kg...