Bidirectional associations between fitness and fatness in youth: A longitudinal study

The aim was to examine the bidirectional association between cardiorespiratory fitness (CRF) and fatness in a 2‐year longitudinal study conducted in young people. A total of 1082 children (512 females) and 727 adolescents (342 females) with complete data at baseline and follow‐up were included. CRF was determined by the 20‐m shuttle run test. Height and weight were measured, and body mass index and fat mass index (kg/m 2 ) were calculated....