Analysis of secular trends in physical fitness of children and adolescents (8–18 years) from Kraków (Poland) between 2010 and 2020

Objectives The aim of the study was to analyze the changes of the motor skills of children and adolescents from Kraków between 2010 and 2020. Methods The group included 4106 children and adolescents (8–18 years of age). The analysis of changes included results of the following fitness tests: backwards overhead medicine ball throw, standing broad jump, dynamometric strength of the hand, flexibility test, as well as shuttle run (10 × 5 m). Results A negative trend in both sexes was observed in the results of overhead medicine ball throw. The girls also had a negative intergenerational changes in the results of the shuttle run and the flexibility test. A positive secular trend was also observed in both sexes in relations to the dynamometric force of the right and left hand. In addition, the boys studied in more contemporary times showed better results in the shuttle run, compared to their peers in 2010. Conclusion The study reported a decline in overall motor performance in children and adolescents. The observed results may be related to a decrease in the level of physical activity, as well as a higher incidence of overweight and high levels of body fat in the modern population.