Hormonal response during official bouldering competition.

BACKGROUND: Sports competitions present a highly stressful environment for the athletes. The stress that is produced because of physiological or psychological demands could influence athletes' performance. This study aimed to understand the dynamics of stress biomarkers during official national bouldering climbing competition. METHODS: Twelve sport climbers ([6 females] average age: 20.3±5.21 years, body height: 174.0±10.27 cm, body mass: 64.7±10.80 kg, training age: 10.3±2.40 years) took part in this study. Their saliva cortisol (C) and alpha-amylase (AA) were sampled during the official climbing competition (qualification and final). RESULTS: The results showed that C had higher values post- (qualification, 1.02±0.43 µg/dL; final, 0.46±0.27 µg/dL) than precompetition (0.45±0.24 µg/dL; 0.29±0.68 µg/dL, respectively). A similar trend can be observed in AA, with higher values post- (qualification, 156.07±133.24 U/dL; final, 199.09±51.24 U/dL) than precompetition (88.18±80.24 U/dL; 88.72±51.24 U/dL, respectively). Furthermore, C had a significantly higher response prequalification (0.45±0.24 µg/dL) than prefinal (0.29±0.19 µg/dL), with the same response post both competition rounds (qualification, 1.02±0.43 µg/dL; final, 0.46±0.27 µg/dL). CONCLUSIONS: Overall, the results showed a strong endocrine and nervous system response. These findings lead to the conclusion that sports climbing competitions present a highly stressful environment for athletes, both physically and psychologically.

Construction and Validation of Newly Adapted Sport-Specific Anaerobic Diving Tests.

Breath-hold diving is explained as an activity that requires enduring muscle asphyxia and acidosis, high anaerobic capacity, and the tactic of the dive. Therefore, this study aimed to construct and validate tests that will mimic anaerobic processes in the specific media of freedivers. The sample of participants included 34 Croatian freedivers (average age: 26.85 ± 4.0 years, competitive age: 3.82 ± 1.92 years, their body height: 180.14 ± 8.93 cm, and their body mass: 76.82 ± 12.41 kg). The sample of variables consists of anthropometric indices, competitive efficiency (maximal length of a dive (DYN)), and specific anaerobic capacities (100 m and 2 min tests). Newly developed tests included the swimming anaerobic sprint test (SAST) and diving anaerobic sprint test (DAST). DAST and SAST variables included the total time of the test (DAST/SAST) and the fastest interval (DASTmax/SASTmax). The results showed good reliability of the tests with high Cronbach alpha coefficients (DAST: 0.98, DASTmax: 0.97, SAST: 0.99, SASTmax: 0.91). Furthermore, pragmatic validity shows a high correlation among all variables and DAST (DYN: -0.70, 100 m: 0.66, 2 min: -0.68). High relation is also found between 100 m (0.96), 2 min (-0.94), and a moderate result for DYN (-0.43) and the SAST test. A factor analysis extracted one significant factor. The factor analysis involved DAST, SAST, DYN, 100 m, and 2 min tests regarding factor 1. After the examination of all variables, the total time of the DAST test showed the best predictive values for the performance of divers. However, both tests could be used for diagnostics and the evaluation of specific condition abilities in freediving.

Do freedivers and spearfishermen differ in local muscle oxygen saturation and anaerobic power?

BACKGROUND: Freediving is defined as an activity where athletes repetitively dive and are exposed to long efforts with limited oxygen consumption. Therefore, anaerobic features are expected to be an important facet of diving performance. This study aimed to investigate differences in anaerobic capacity and local muscle oxygenation in spearfisherman and freedivers. METHODS: The sample of participants included 17 male athletes (nine freedivers, and eight spearfishermen), with an average age of 37.0±8.8 years, training experience of 10.6±9.5 years, body mass of 82.5±9.5 kg and height of 184.2±5.7 cm. Anthropometric characteristics included: body mass, body height, seated height, and body fat percentage. Wingate anaerobic test was conducted, during which local muscle oxygenation was measured with a NIRS device (Moxy monitor). Wingate power outputs were measured (peak power [W/kg] and average power [W/kg]), together with muscle oxygenation variables (baseline oxygen saturation [%], desaturation slope [%/s], minimum oxygen saturation [%], half time recovery [s], and maximum oxygen saturation [%]). RESULTS: The differences were not obtained between freedivers and spearfisherman in power outputs (peak power (9.24±2.08 spearfisherman; 10.68±1.04 freedivers; P=0.14); average power (6.85±0.95 spearfisherman; 7.44±0.60 freedivers; P=0.15) and muscle oxygenation parameters. However, analysis of effect size showed a moderate effect in training experience (0.71), PP (0.89), AP (0.75), Desat slope mVLR (0.66), half time recovery mVLR (0.90). CONCLUSIONS: The non-existence of differences between freedivers and spearfishermen indicates similar training adaptations to the anaerobic demands. However, the results show relatively low anaerobic capacities of our divers that could serve as an incentive for the further development of these mechanisms.

Acute and Long-Lasting Effects of Slow-Paced Breathing on Handball Team Coach's Match Stress.

Stress was previously defined as a response to any demand for change. These demands are noticeable during sport events, not only in athletes but also in coaches. Therefore, this study aimed to determine the influence of slow-paced breathing (SPB) on acute stress to handball coaches during official matches. One professional handball coach, aged 37 (height, 180 cm; weight, 80 kg), took part in the study. His salivary cortisol (C) concentration and alpha-amylase (AA) activity were measured, and his heart rate (HR) was monitored during six official matches. In the first three matches the SPB training protocol was not followed. From match four to match six, the coach performed SPB training every day and directly before the match. The decrease observed in AA was statistically significant with a large effect size (1.80). The trend of change in HR is visible and similar for matches with and without SPB. However, for SPB matches, there is a lower starting point compared to matches without SPB (89.81 ± 6.26 and 96.62 ± 8.10, respectively). Moreover, values of AA on SPB matches were smaller before the match (93.92 ± 15.89) compared to the same time point in non-SPB matches (115.30 ± 26.00). For AA, there is a significant effect size in the half-time (2.00) and after the match (-2.14). SPB matches showed a lower increase in AA. SPB might be used as one of the possible tools that could help coaches in achieving a desirable mental state during the match.

Determinants of COVID Vaccination Willingness among Health and Non-Health Studies Students: A Cross-Sectional Study.

Students, as a relatively health-informed population group, may still have limitations in health literacy, which is a concern as students take increasing responsibility for their health and make independent health decisions. The aim of this study was to evaluate the overall attitudes towards COVID vaccination among university students and to investigate various factors contributing to vaccination willingness among health and non-health studies students. A total of 752 students from the University of Split were included in this cross-sectional study and completed a questionnaire that consisted of three sections: socio-demographic data, health status information, and information on vaccination against COVID-19. Results show that the majority of students of health and natural sciences were willing to be vaccinated, but the majority of students of social sciences were not (p < 0.001). Students who used credible sources of information had a more significant proportion of those willing to be vaccinated and the majority of students who used less credible sources (79%) or did not think about it (68.8%) were unwilling to be vaccinated (p < 0.001). Multiple binary logistic regression modeling shows that female gender, younger age, studying social sciences, negative opinion about the need to reintroduce lockdown and the effectiveness of epidemiological measures, and usage of less credible sources of information were the most important factors contributing to increased vaccination hesitancy. Therefore, improving health literacy and restoring trust in relevant institutions can be critical in health promotion and COVID-19 prevention.

Forearm muscle oxygenation and blood volume parameters during sustained contraction performance in youth sport climbers.

BACKGROUND: Forearm muscle strength and endurance are essential determinants of sports climbing success. This study aimed to investigate whether delayed rates of muscle oxygen saturation and total hemoglobin correlate to sustained contraction performance of youth climbers. METHODS: Twelve recreational and competitive youth sport climbers (six females, six males) participated in the study. Variables included finger flexors muscle maximal voluntary contraction, sustained contraction test (SCT), muscle oxygen dynamics (SmO2), and blood volume (tHb) parameters. Pearson's correlation coefficients were calculated to determine the correlation between physiological and performance variables. RESULTS: SCT had a significant positive relationship to SmO2 delayed rate (r=0.728, P=0.007), and a significant negative relationship to tHb delayed rate (r=-0.690, P=0.013). SmO2 delayed rate and tHb delayed rate also had a significant negative correlation (r=-0.760, P=0.004). CONCLUSIONS: According to the results of this study, it can be suggested that delayed rates of SmO2 and tHb could be used in determining and predicting sustainable finger flexors performance in youth climbers. However, future studies investigating delayed rates of SmO2 and tHb in climbers of different ability levels are warranted to investigate this issue in more detail.

Differences between Elite and Professional Male Handball Players in Kinematic Parameters of Single Fake Movement.

Feint movement is an important factor for offensive players to outplay their guard, and score. So far, there is no evidence of feint biomechanical analysis on a sample of elite players in handball or other team sports. Therefore, this study aimed to investigate kinematic parameters of single side fake movement between elite and professional level handball players. The sample of participants consisted of 10 handball players divided into two subsamples: elite handball players (100.00 ± 8.00 kg; 196.00 ± 4.64 cm) and professional handball players (91.20 ± 3.42 kg; 192.4 ± 7.30 cm). The kinematic analysis was conducted using a GAIT-LaBACS software system. Variables consisted of two phases (fake phase and actual phase) of feint single change of direction. Both phases included seven kinematic parameters that were observed. Statistical analysis included descriptive statistic parameters. The differences between elite and professional handball players were analyzed by multivariate and univariate variance analysis. Results showed significant differences between elite and professional players (λ = 0.44, p = 0.00), in fake phase (i.e., 1. Phase). The results also indicate that in there is no statistically significant difference between both groups (λ = 0.64, p = 0.22). Two variables had significant differences between elite and professional players (i.e., step length of the stride leg (p = 0.02) and moving the leg opposite the throwing arm in space (p = 0.00)). To conclude, the article examines specific movement patterns of single side fake movement in elite players and the confirmed importance of efficient skill execution in top level handball. On the contrary, less skilled players use more space for the same technical element.

Comparison between Match and Training Session on Biomarker Responses in Handball Players.

A variety of loads are placed upon an athlete in team sports (e.g., training, match, or competitions). However, the volume of the training load plays an important role in match success. Therefore, the aim of this study was to compare the differences in biomarker dynamics during the match and during training, and to evaluate if such training represents a good stimulus for an athlete to adapt to match stress. Ten male handball players (average age of 24.1 ± 3.17 years, body height of 1.88 ± 0.64 m, and body mass of 94.6 ± 9.6 kg) took part in this study. Their saliva cortisol, testosterone, and alpha-amylase were sampled during the match and training (sessions of 90 min duration, respectively). The results showed that cortisol had higher values after the match (0.65 µg/dL) than after training (0.32 µg/dL) (p = 0.05; ES = 0.39). Testosterone concentrations had a steeper increase during a match (65%) than after training (37%). Alpha-amylase levels did not differ significantly between the match and training (p = 0.77; ES = -0.06). Overall, the results showed that the environment of a match was more stressful for the athletes; therefore, a match provoked a stronger endocrine response in the studied markers. Therefore, we concluded that a match seemed to be a stronger trigger for all of the measured biomarker responses.

Comparative screening the life-time composition and crystallinity variation in gilthead seabream otoliths Sparus aurata from different marine environments.

Differences in crystallinity, structure and composition variation along the growing direction in gilthead seabream, Sparus aurata otoliths that inhabited different environments were determined to evaluate the correlation of spectroscopic and chemical data with the lifetime development and movement pattern. The Raman spectroscopy signal provided the characteristic bands whose Full Width at Half Maximum (FWHM) were used to track the signal variability. The FWHM showed an initial increase in the core area, followed by a decrease depicting two minima coinciding growth rings. The crystal discontinuity linked to annual rings was confirmed. The FWHM pattern followed cycle in the individual's activity. However, no significant correlation with FWHM and environmental factors although the slope of the FWHM variation distinguished aquaculture and costal groups from open sea and transitional, estuarine waters. Raman data were further correlated with morphological and elemental composition obtained via SEM-EDX and by LA-ICP-MS. SEM clearly confirmed CRM findings. Finally, multiparameter analysis of Ba/Ca concentrations obtained by LA-ICP-MS indicated the separation of groups associated with aquaculture and transitional waters due lowest variability in the elemental composition. Other groups are more variable possibly due to the water oligotrophic character and greater variability in prey availability in each environment. Results of the present study showed the additional potential of Raman spectroscopy as a complementary tool for inference of migration or origin of fish based on otolith composition and structure like other well-established technique.

Early evidence of a shift in juvenile fish communities in response to conditions in nursery areas.

A multivariate analysis of juvenile fish community data, sampled at two nursery sites at an interval of 17 years (2000-early, and 2017-late), was conducted to elucidate the trends of change in littoral juvenile fish communities along the eastern Adriatic coast. Fishing, trophic and taxonomic composition to the community data were analysed for possible causality. The ichthyofaunal composition differed significantly for Site, Period and all interactions. According to the mMDS ordination plot, four groups of communities were defined, with clear cyclicity. No patterns were found in species composition between sites in the early period, while the observed community changes were governed by the same pattern at both sites in the late period. The species that contributed most to the observed changes were non-commercial, small, benthic resident fishes, such as gobiids and blennids, or those associated with canopy alga for shelter and feeding. The analysis correctly allocated samples based on community information to Sites and Periods. The data obtained provided an invaluable opportunity to test for the generality of potential patterns of change in littoral fish communities, suggesting that significantly modified juvenile fish communities may be the result of constant human embankment and marine infrastructure construction along the coast in recent decades, rather than climate change or fishing pressure, as generally considered.

Otolith fingerprints reveals potential pollution exposure of newly settled juvenile Sparus aurata.

Coastal ecosystems are increasingly threatened by a wide range of human activities. Fish otolith chemistry, by creating a unique specific signature, can be used as a natural tag for determining life stage dispersal, spatial connectivity and population structure. In this study, we tested whether differences in otolith composition among juveniles of gilthead sea bream, Sparus aurata, could enable their proper allocation to polluted areas based on higher concentrations of elements related to contaminants. Otoliths were embedded, sectioned and analysed by LA-ICP-MS in line scan mode. Multivariate analysis confirmed clear separation between sites and elements. Samples from the site under the strongest anthropogenic impact from industrial and agricultural river input were characterized by higher values of Pb/Ca and Zn/Ca. However, these relatively low values likely do not have a negative effect on S. aurata recruitment, though they could serve for identifying the contribution of polluted nurseries to stock dynamics.