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 goal of this study was to define the individual model characteristics of lactic acid removal after 200m breaststroke competitive load in a female swimmer in relation to different pool lengths (25m vs. 50m). The second goal was methodological and referred to the presentation of newly applied metrological procedures for the Individual Lactate Recovery Profile modeling. Six races from the competitive season 2021/22 were selected, in which the athlete achieved the most valuable results in relation to the FINA score. To establish the metabolic response of the organism to the competition effort, the method of determining the level of lactate concentration in capillary blood (La in mmol/L) was used. Differences between the mean values of variables were established using ANOVA. The polynomial curve equation function was used to create a blood lactate concentration in a function of recovery time model (La-trecovery). The ANOVA showed that there was no statistically significant difference between the monitored variables and the pool length function (p=.097). The maximum achieved blood lactate concentration in the acute race recovery phase was 13.17 ± 2.81 and 12.08 ± 1.80 mmol/L and the given concentration initially occurred in the time of 240.0 ± 85.6 s and 169.3 ± 79.9 s in the 25 and 50m pool, respectively. In relation to the time of complete passive recovery required to establish acidosis at the level of 2 mmol/L (25 and 50m pool) occurred in 1191.7 ± 481.3 s and 1326.7 ± 405.1 s, while the full index of intensity of blood lactate clearance was 135.7 ± 60.7 s/mmol/L and 124.0 ± 60.7 s/mmol/L for 25m and 50m pool, respectively. Although no statistically significant difference was found between the parameters of recovery in relation to pool length, the offered mathematical models enabled a practical individual approach to controlling the specific adaptation to training for achieving a higher competitive level performance.

The aim of this study was to determine possible changes in physical performance and morphological characteristics in young basketball players before and after quarantine caused by COVID-19. The research was conducted on a total sample of 46 young basketball players. Participants were measured before the quarantine and pandemic in January 2020 and then after the quarantine period, one year later in March 2021. The results indicate the existence of significant differences in total muscle mass (p < 0.01) in favor of higher values measured before quarantine. Moreover, total fat percentage was higher (p < 0.03) after quarantine. As for physical performance, significant differences were also observed in the counter movement jump test (p < 0.05) and the 20 m shuttle run test (p < 0.05), with significantly poorer results for the group of participants measured after quarantine. The authors conclude that the consequences of the quarantine and pandemic of the SARS-CoV-2 virus were definitely negative, as higher values of body fat and lower values of the percentage of total muscle mass were observed. In addition, a lower level of the explosive power of lower limbs was observed, accompanied by lower aerobic endurance in young basketball players.

The need to determine the factors that positively or negatively affect the acquisition of swimming knowledge arose with the development of various swimming programs. The aim of this research was to determine the connection between the level of anxiety and success in the process of motor learning in swimming training program for non-swimmers. A sample of 77 children, aged (11.00±0.71), participated in a swimming training program for non-swimmers for 20 hours according to the standard method used in the Republic of Croatia. In the first and last lesson, the swimming knowledge was determined by means of a scale of eleven grades that describe the level of acquisition of swimming knowledge. Level of anxiety was assessed by modified CSAI-2CSWIM anxiety level questionnaire. Correlation analysis determined that the level of anxiety has a significant negative correlation with performance in all three observed domains, cognitive anxiety -0.273 and -2.46, somatic anxiety -0.384 and -0.337 and self-confidence -0.420 and -0.308 with results on the final test and with progress in swimming learning. The results of the conducted research showed that the level of anxiety has a significant influence on the children’s swimming learning process.

In recent research, we found that the use of goggles and snorkel benefited non-swimmers with fear of water in a learn-to-swim program. Our purpose in this study was to examine the effects of using goggles and snorkel during a learn-to-swim program on the aquatic skills of young non-swimmers without fear of water. We modelled this research on our prior study. Following informed parental consent, 40 children (aged 10–11 years) were randomly divided into two groups: one that used goggles and snorkel (GS) and one that did not (NGS). After 4 weeks (five sessions per week) of learn-to-swim intervention, both groups improved aquatic skills such that the only group differences were for the blowing bubbles test, for which the learn-to-swim program resulted in smaller gains for the GS than the NGS group. Thus, the use (vs. non-use) of goggles and snorkels during the learn-to-swim program had no significant effect on most aquatic skills of young non-swimmers without fear of water. The only exception was a significant finding of reduced improvement in blowing bubbles in the goggles and snorkels group when compared to the no goggles and snorkel group. Together with past findings these results highlight important learn-to-swim differences between young non-swimmers with and without fear of water.