Reliability of force-time curve characteristics during maximal isometric leg press in differently trained high-level athletes

The aim of this research was to establish the metrologic values of the isometric force-time characteristics of leg extensors in differently trained, healthy male athletes and non-athletes. 99 subjects performed a standardized “isometric leg press” test. Even though the results showed a high statistical significance in terms of representativeness, generalizability and reliability for all contractile characteristics of observed measured variables, different methodological approaches were required in order to obtain the most valid results for differently trained and untrained subjects. Based on the results obtained, and from the aspect of the methodology of testing different isometric force characteristics, it was possible to conclude that the standardization of the isometric leg press requires two trials in football, where the most reliable data was from the first trial (the communality rates (H2) from 0.866 to 0.969). Water polo and basketball require three trials. The most reliable data was from the third and second trial in water polo (H2 from 0.909 to 0.986). In basketball the most reliable data was from the second trial (H2 from 0.824 to 0.987). The untrained healthy adult population requires four trials, and the most reliable data was from the third trial (H2 from 0.961 to 0.995).