Abstract
Study aim: To assess the aerobic capacity, sprint velocity and changes in biochemical variables in football players preparing for the spring round of matches.
Material and methods: Football players from League I (n = 19) and League IV (n = 15) were subjected twice to a graded running tests at the beginning and at the end of the pre-season preparation period. The following variables were recorded: maximum running velocity (km/h), O2max (ml/kg/min), pulmonary ventilation (VE), load at the lactate threshold (LT) expressed as the threshold velocity (LTV; km/h) or %O2max, activities of enzymes in plasma - creatine kinase (CK) and lactate dehydrogenase (LDH), concentrations of lactate (La), ammonia (NH3) and of glucose (Gl) in plasma. At the end of the study the players were also subjected to a 30-m sprint test.
Results: In League I players, LT significantly (p