Do Blood Lactate Levels Affect the Kinematic Patterns of Jump Shots in Handball?

The aim of this study was to determine whether the dynamic motor stereotype of movement (shooting technique) is violated under conditions of an increased lactate concentration in a player's blood after a 30-15 intermittent fitness test. The hypotheses was that there would be statistically significant differences in ball speed and shooting accuracy in jump shots on the goal before and after the occurrence of fatigue in the player. The sample of respondents consisted of 10 top-level handball players of the highest competition rank in Croatia. The results showed significant differences before and after the fatigue protocol in the run-up speed (F = 5.66; p = 0.02), in the maximum speed of the forearm (F = 5.85; p = 0.02) and the hand (F = 4.01; p = 0.04), in the speed in the shoulder joint (F = 5.39; p = 0.02) and wrist joint (F = 4.06; p = 0.04), and in the ball shooting speed (F = 5.42; p = 0.02). The accuracy of the shot was, on average, lower (36.20 vs. 33.17 cm) but not significantly so. High blood lactate levels affect changes in certain kinematic parameters during the performance of a jump shot in handball. Consequently, this reduces the speed of the shot, which can affect situational performance as one of the two significant parameters of scoring success.