Over the last few years, numerous studies have proclaimed a negative trend in the motor performance of children and adolescents. Drawing from the online Fitness Olympiad database, the data of 8239 children and adolescents from Germany were analyzed by age, sex, and motor performance measured using the Dordel–Koch–test (DKT). Results were compared from the 2010‐2012 and 2018‐2020 cohorts. The results of the 2010‐2012 and 2018‐2020 cohorts were then compared regarding the general and sex‐specific changes in the development of motor performance. A negative trend was shown for three of five motor performance test items, with decreases of 0.9%‐4.8% in abdominal and leg strength and coordination under time pressure, respectively, being found. In contrast, endurance improved by 0.4% and arm and trunk muscle strength by 3.1%. The negative development can be seen as a correlate of exercise deficit disorder (EDD) due to increasing sedentarism. Therefore, the correlation between motor performance and health indicates a clear motivation to appropriately promote the main forms of motor activity.