Long-term effect of migration background on the development of physical fitness among primary school children.

Primary school children with and without MB significantly increased their physical fitness over time in a comparable manner. However, children with MB showed a significantly lower physical fitness at all test time points, which was only partly explained by a higher mean BMI in children with MB. Children with MB outreached the mean baseline fitness level of children without MB not until the fourth test time point, that is after two years. Therefore, a special focus on physical fitness particularly including strength and endurance capacities should be directed to children with MB already in young ages.