Tatjana Jezdimirovic-Stojanovic’s scientific contributions

The objectives of this study were to compare the effects of two in-season velocity loss training methods (VBT) on performance outcomes and to evaluate the effects of velocity-based training compared to traditional resistance training (TRT) on performance outcomes in young elite soccer players. VBT utilized the same relative load but varied in the extent of velocity loss during the set: 15% (VL15%) and 30% (VL30%). Thirty-four players were recruited and randomly distributed into three groups: the VL15% group (n = 12; age = 18.50 ± 0.67 years; stature = 183.41 ± 4.25 cm; body mass = 75.08 ± 5.57 kg), the VL30% group (n = 11; age = 17.91 ± 0.60 years; stature = 181.21 ± 6.56 cm, body mass = 73.58 ± 6.22 kg), and the traditional strength training group TRT (n = 11; age = 18.14 ± 0.74 years; stature = 182.17 ± 5.52 cm; body mass = 74.86 ± 6.68 kg). Alongside regular soccer sessions and matches, the groups underwent a four-week (2 sesions per week) resistance training intervention with back squats involved. Changes in leg strength (SQ1RM), 20 m sprint time (SPR 20 m), countermovement jump height (CMJ), reactive strength index (RSI), and change of direction (COD) from before and after were evaluated using a 3 × 2 ANOVA. While no significant interaction was found for SQ1RM and SPR20, all of the groups showed significant pre to post improvements. Significant interactions were observed for CMJ (F = 38.24, p = 0.000), RSI (F = 8.33; p = 0.001), and change of direction agility test (COD) (F = 3.64; p = 0.038), with a post hoc analysis showing differences between the VL15 (6.0%) and TRT (1.7%) groups (p = 0.034); VL15 (12.2%) and VL30 (3.2%) groups (p = 0.004); VL15 and TRT (0.4%) (p = 0.018); VL15 (2.4%) and VL30 (1.5%) (p = 0.049); and between the VL15 and TRT (0.4%) groups (p = 0.015). Four weeks of VL15% training during the season induced similar strength increases to VL30% and TRT, superior improvements in RSI and COD compared to VL30%, and superior improvements in CMJ, RSI, and COD tests compared to TRT. Thus, incorporating the VL15% training method may be recommended to improve power-related performance metrics in elite young soccer players.

The aims of this study were: 1. to investigate the influence of pre-shooting activity on the three-point jump shot entry angle and release time in regional level basketball players; 2. to examine age related differences in these parameters between juniors and seniors. Thirty three perimeter players , were assigned to juniors (n=16, age=17.34±0.54 years; height=191.3±8.18 cm; weight= 77.08±7.41 training experience=6.75±2.30 years) and seniors (n=17, age=22.79±4.47 years; height =194.4±7.47 cm; weight= 80.42±7.45d; training experience= 12.18±3.17 years) had three sets of 5 shots, with a different preparatory phase for every set: 1. spot shot, 2. after two forward steps, or 3. after one dribble. Only successful shots (n= 233) were analyzed. The difference between groups was determined with ANOVA, while the differences in shot accuracy were determined by the chi-square test. Study results reported no statistically significant differences in entry angle and release time for 3 different pre-shooting patterns. Seniors had significantly higher shooting accuracy (X2=3.097; p=0.048, φ=-0.089) higher entry angle (p < 0.001) and lower release time (p < 0.001) than juniors for all successful shots combined, and significantly higher (p < 0.001) entry angle for every set independently. Significant difference in shooting accuracy with medium effect size (X2= 6.645; p=0.010, φ=-0.20) was observed in shots after movement. Seniors had statistically lower release time for set 1 (p=0.004) and 2 (p=0.002) independently. Age-related group differences in shooting parameters should be considered to optimize training prescription for basketball players.