The purpose of study was to resolve the effect of plyometric training and repeated sprint training on physical performance. The study was conducted on 41 subjects in two experimental groups (plyometric/repeated sprints training). Before and after the training program, subjects were subjected to diagnostic procedures that included standard test protocols. Results proved a statistically significant difference only after the plyometric training program compared to the repeated sprint group in countermovement jump (8.65% vs. 2.21%). In variable repeated jumps, an increased value was recorded (2.9% vs. 4.29%), like in sprint variables after the training program where certain trends of progress happened after the repeated sprint ability training and the specificity of the program (5 m = 0.89%, 10 m = 1.07% and 25 m = 1.35%), while plyometric training recorded unchanged values at 5 and 10 m, and a 0.27% improvement at 25 m. Stagnation of the 20-yard test was recorded in both groups. There was no difference between training programs in any variables of functional capacities, with similar measures recorded in repeated sprint ability. After six weeks of both training types, positive changes can be expected in explosive strength of lower extremities, increases in acceleration area, and maximum speed.

Metabolic syndrome is a group of metabolic risk factors whose combination significantly contributes to the development of the risk of cardiovascular disease, diabetes, stroke, some cancers and is a clear indicator of morbidity rate. The aim of this study was to identify physical activity programs that can successfully influence the reduction of risk factors in metabolic syndrome of the elderly. Subjects were aged between 60 and 80 years, had three of five signs of metabolic syndrome, and were randomly divided into three groups of 20 subjects. The first group conducted a continuous cycling ergometer (55% VO₂max), the second group a physical activity strength program and the third was a control group. Before and after the experimental treatment body composition, biochemical parameters, functional parameters, cardiovascular functions, metabolic and hematological system were determined. Significant differences between control and experimental groups were determined using MANOVA. The training effects of the experimental and control groups were determined using the ANOVA for repeated measurements with Bonfferoni correction. The results showed that a physical activity program of strength has a better effect on disease regulation in the elderly with metabolic syndrome than a moderate-intensity physical activity program which also has a significant change but in less variables.

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.

The main aim of this research is to analyse the kinematic model of two different variations of executing the jump shot, one performed after one step in the preparation phase and the other performed after a three-step preparation phase (run-up). Respondents (N = 27) are female Croatian national handball team players (U17 and U19). After basic anthropometric and morphological measurements, along with the warmup, respondents proceeded to shoot with one- and three-step shots directed at targets in the upper and lower opposite corner of the goal. A significant difference was found in all measured kinematic parameters between one- and three-step jump shots: hand velocity (p < 0.001 for the upper opposite (UO) and p < 0.001 for the lower opposite target (LO)); hand height reached (p < 0.05 UO and p < 0.01 LO); jump height (p < 0.001 UO and p < 0.001 LO); shoulder velocity (p < 0.001 UO and p < 0.001 LO); and ball velocity (p < 0.05 UO and p < 0.01 LO). Coaches should incorporate specific jump shots after one step to automate this movement and produce the best shooting technique, which will allow them to have smaller differences or no differences between techniques with three-steps and one-step jump shots. Consequently, this will lead to better performance indicators which consist of shooting on target from various positions in the field.

The purpose of the study was to determine the correlation of quality of the refereeing in handball with the morphological characteristics of referees, along with their age and experience. Subjects are 16 pairs (N = 32) of top-level handball referees in Croatia (age 34.66 ± 6.44, height 184.02 ± 5.87 cm, body mass 91.14 ± 10.61 kg, body fat 19.20 ± 3.94% and body mass index 26.91 ± 2.47 kg/m²) which have conducted morphological measures and tests for determination of their morphological status in the first part of the study. In the second part of the study, referees were evaluated in top-level handball matches to determine if their morphological status had an influence on the quality of refereeing. The correlation of quality of the refereeing with body fat was tested and there is no significant correlation (p = 0.75). Pearson’s correlation coefficient proves that total experience in refereeing does not have an influence on the quality of refereeing (r = 0.30), and neither does the age of referees (r = 0.23). Experience of refereeing in the highest rank has a statistically significant influence on the quality of refereeing (r = 0.62). Existing elimination criteria (measurement of morphological characteristics and functional abilities at official tests) that referees must satisfy at official seminars before the beginning and in the middle of the season make the selection of referees. Based on these facts, it is concluded that the existing selection of referees is good and there is no great variability among them, considering their morphological characteristics. Experience in refereeing is significant for the quality of refereeing, especially experience in the highest level of competition.