The secular trend of reduced physical fitness (PF) leads to increased health risks. The aim of the present paper is to analyse various current factors that affect health behaviour with respect to the course of PF over 2 years. A path analysis combined with a latent growth curve analysis was based on a study that was conducted between June 2008 and June 2010 with 145 primary German school children (52.1% male, average age at baseline 7.95 years ± 0.95). PF was tested with the German Motor Test 6-18. For the mean PF and the course of PF, direct and indirect influences were shown over three levels, including migration background on the first level and physical activity (PA) on the second level. Body mass index (BMI) impacted the mean PF but not the course of PF. The influence of sedentary behaviour on the mean PF was diminished (compared to bivariate analysis) due to its common variance mainly with BMI. PA affected not only current PF in children but also the course of PF (a(intercept) = .28, P = .001; a(slope) = .27, P = .21). Consequently, preventive measures should focus on early adoption and maintenance of PA.
Keywords: BMI; Migration background; media; physical activity; school achievement.