摘要：Introduction . Since the competition period has been prolonged in modern football, it is important to know if a shortened preparatory phase is enough to improve motor fitness preparation. This study analysed the changes in the level of physical fitness in second-league soccer players with respect to training conducted during the preparatory period. Material and methods . Speed (5-m and 30-m sprint), endurance (progressive test), and power (Counter Movement Jump) were tested in 21 players at the beginning and at the end of the preparatory phase. Results . The results obtained indicate a significant improvement in physical capacity parameters as well as speed and strength abilities measured using 5-m and 30-m running speed tests and the CMJ test for muscle power. In the progressive test measuring anaerobic threshold speed, the players active in the central section of the pitch (centre-backs and central midfielders) achieved the best results, while in the speed trials and explosive strength trials, side-backs and side midfielders achieved the best results. Conclusions . During the winter preparatory season, the most significant changes in the physical fitness of soccer players were observed in aerobic endurance expressed as threshold speed (an increase of 1.2 km/h) and running speed measured as the time needed to cover a distance of 5 m (time reduced by 0.04 s) and 30 m (time reduced by 0.07 s). These traits are crucial in the preparation of soccer players for league matches and have the greatest impact on their performance in sports competitions.
关键词：football ; physical fitness ; preparatory phase ; motor preparation
