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Öğe The acute effects of simulated hypoxic training at different altitudes on oxidative stress and muscle damage in elite long-distance runners(PeerJ, 2025-05-12) Mücahit Sarikaya; Beyza Öğe; Nuri Mert Embiyaoğlu; Muzaffer Selçuk; Vedat Çınar; Salih Öner; Yıldırım Gökhan Gencer; Mehdi Aslan; Mustafa Sencer Ulema; Yunus Emre Yarayan; Kadir Keskin; Nouf H. Alkhamees; Bodor Bin Sheeha; Gerasimos V. Grivas; Sameer Badri AL-Mhanna; Alexios BatrakoulisBackground: Understanding the impact of altitude on muscle damage and oxidative stress is essential for optimizing training and recovery strategies for athletes exposed to high-altitude conditions. Therefore, this study aimed to investigate the effects of acute exercise at different altitudes on oxidative stress and muscle damage. Methods: A total of twelve elite long-distance runners (mean age: 20.3 ± 1.5 years) from different branches participated in the study. The exercise protocol was the Bruce submaximal treadmill exercise test, which was conducted under three simulated hypoxic conditions (at 1,700 m, 2,450 m, and 3,200 m) and one normoxic condition (sea level). All measurements took place at the same time of the day. After the exercise protocol, 5 ml venous blood samples were taken from the participants, while heart rate and oxygen saturation were monitored at the 3rd, 6th, 9th, and 12th minutes during the exercise. Results: Significant altitude-dependent variations were observed in oxidative stress markers, with total oxidant status (TOS) (p = 0.017) and malondialdehyde (MDA) (p < 0.001) levels increasing at higher altitudes, while total antioxidant status (TAS) (p < 0.001) exhibited an elevation and oxidative stress index (OSI) (p < 0.001) demonstrated a decline as altitude increased. However, no significant difference was found in creatine kinase (CK, p = 0.059) levels. Additionally, there were significant differences in the oxygen saturation measurement taken at the 3rd (p < 0.001), 6th (p < 0.001), 9th (p < 0.001), and 12th (p < 0.001), minutes following the exercise session. There was no difference in the pulse measurement taken at the 3rd and 12th minutes, but a difference was observed at the 6th and 9th minutes post-exercise (p < 0.01). Conclusions: In conclusion, the study determined that endurance exercises performed under simulated normobaric hypoxia at different altitudes increased TAS and reduced OSI in elite long-distance runners. The increase in TAS and the reduction in OSI were more pronounced at higher altitudes, particularly at 2,450 m and 3,200 m, compared to sea level. These findings highlight the need for altitude-specific training and recovery strategies to minimize oxidative stress and muscle damage in athletes.Öğe Impact of different exercise modalities on neuroendocrine well-being markers among university students: a study of renalase and catecholamine responses(Frontiers Media SA, 2025-05-01) Vedat Çınar; Mehmet Fırat Bağ; Mehdi Aslan; Fidan Çınar; Alessandro Gennaro; Taner Akbulut; Gian Mario MigliaccioCatecholamines (epinephrine, norepinephrine, dopamine) and renalase are among the key biomolecules that regulate stress responses during exercise and support physiological adaptation. However, the effects of different exercise types on these biomolecules remain unclear. This study aims to compare the effects of aerobic, anaerobic, and strength exercises on epinephrine, norepinephrine, dopamine, and renalase levels. Materials and methods: This study was conducted using a pre-test post-test controlled experimental research design. A total of 80 healthy male participants aged 18-22 years were included and randomly assigned into four groups: control (C), aerobic exercise (A), anaerobic exercise (An), and strength training (Sa). The exercise groups followed specific training protocols for 8 weeks, 3 days per week, at the same time of the day under standardized environmental conditions. Venous blood samples were taken before and after the exercise program, and epinephrine, norepinephrine, dopamine, and renalase levels were analyzed using the ELISA method. Results: Significant increases in epinephrine, dopamine, and renalase levels were observed depending on the exercise type (p < 0.01), while norepinephrine levels showed a significant decrease only in the aerobic exercise group (p < 0.05). Epinephrine levels increased in the aerobic (36.96%), anaerobic (35.42%), and strength training (27.45%) groups, while norepinephrine levels decreased only in the aerobic exercise group (6.38%). Dopamine levels increased in all exercise groups, with the highest change observed in the anaerobic exercise group (38.34%). Renalase levels increased in all exercise groups (p < 0.01), with the highest increase recorded in the anaerobic exercise group (29.42%). Conclusion: This study demonstrated that different exercise modalities induce specific neuroendocrine responses. All exercise types led to significant increases in epinephrine, dopamine, and renalase levels, with the most pronounced effects observed in the anaerobic exercise group. Strength training also produced similarly robust responses. Norepinephrine levels showed a significant decrease only in the aerobic exercise group, while non-significant reductions were observed in the other exercise groups. These findings indicate that exercise type distinctly modulates hormonal and enzymatic pathways involved in physiological adaptation.Öğe How does leadership team coherence affect collaborative learning and academic optimism in a centralized education system?(SAGE Publications, 2025-05-11) Yurdagül Doğuş; Emine Doğan; Mehmet Sabir ÇevikAcademic optimism has been one of the important study subjects of researchers in recent years due to its impact on organizational variables and schools, especially in the field of educational management and leadership. This study aims to examine the mediating role of collaborative teacher professional learning and the moderating role of enabling school structure in the relationship between leadership team coherence and academic optimism. Therefore, the study was designed as a cross-sectional study in quantitative research method. And 1204 teachers working in 1204 public schools in 52 provinces in the west, middle, east, north, and south of T & uuml;rkiye, determined by stratified random sampling method, participated in the research. Results showed that collaborative teacher professional learning mediated the relationship between leadership team coherence and teachers' academic optimism. Additionally, the effect of leadership team coherence on collaborative teacher professional learning, and through collaborative teacher professional learning on academic optimism, was stronger when the enabling school structure was moderate and high. Our results provide evidence that in the Turkish school context, enabling school structure moderates the effect of leadership team cohesion on teachers' academic optimism through collaborative learning. Our research also provides valuable insights that can provide a framework for promoting collaboration and an enabling structure in schools.Öğe The role of athletic mental energy in the occurrence of flow state in male football (soccer) players(Springer Science and Business Media LLC, 2025-03-18) Yunus Emre Yarayan; Alexios Batrakoulis; Nuri Berk Güngör; Serkan Kurtipek; Kadir Keskin; Okan Burçak Çelik; Doğukan Batur Alp Gülşen; Gerasimos V. Grivas; Sameer Badri Al-Mhanna; Nouf H. Alkhamees; Bodor Bin Sheeha; Abdullah F. AlghannamBackground: This study examines the determinant role of athletic mental energy on the flow state in professional football (soccer) players. This research fills an important gap in the sports psychology literature by focusing on the interaction between mental energy and flow, a critical component of optimal performance. Methods: Accordingly, 254 male athletes (Mean age = 23.1 ± 5.4 years) voluntarily participated in the study. This study was designed with the relational survey model, one of the quantitative research models. Athletic Mental Energy Scale and Dispositional Flow State Scale-2 were used as data collection tools. After confirming the validity and reliability of the scales, the data were analyzed. In this study, blank data were first evaluated to check the suitability of the analysis and assumptions. After the structure of the scales was verified, firstly, when the skewness kurtosis values for the normality test were examined, it was deter-mined that the data were suitable for normal distribution as the values were between - 1.5 and + 1.5 and the Q-Q graph did not show deviations from the distribution. In this context, Pearson Correlation Analysis was used to determine the relationship between athletic mental energy and flow state, and structural equation modeling (SEM) analysis was used to determine the determinant role of mental energy. Mental energy significantly predicted the flow state (β = 0.81, p < 0.05), and the SEM results indicated a good model fit (χ²/df = 2.96, RMSEA = 0.08, GFI = 0.89, CFI = 0.90). Results: When the findings obtained from the research were analyzed, it was determined that athletic mental energy was a determinant of flow and contributed to 66% of the variance. Conclusion: As a result, it supports that athletes' mental energy levels play an important role in their performance and contribute to the increase of optimal performance mood. These findings suggest that coaches and sports psychologists should focus on strategies to enhance athletes' mental energy levels, such as incorporating mental skills training into their routines. The study emphasizes the importance of athletes' ability to manage their mental energy levels and the development of strategies to increase optimal performance mood. By providing evidence for the link between mental energy and flow, this study contributes to advancing the understanding of performance optimization in professional sports.Öğe Determining the levels of social anxiety and emotion regulation difficulties among youth participating in sports courses at youth centers(Servicio de Publicaciones de la Universidad de Murcia, 2025-02-28) Buşra Özcan; Yunus Şahinler; Mahmut Ulukan; Mustafa Can KoçThe aim of this study was to examine the relationship between social anxiety levels and emotion regulation difficulties among adolescents participating in sports courses at youth centers. The study included 206 young individuals (64.6% female and 35.4% male), aged 11-18, attending youth center courses across Turkey. A Google Forms survey was used for data collection, applying a convenience sampling method to reach 206 youth center participants. Data were collected using social anxiety and emotion regulation scales applied to individuals residing in a specific geographical region. The findings reveal that social anxiety levels are significantly associated with demographic factors such as age, gender, and parental education (p<0.05). Furthermore, adolescents with high levels of social anxiety are more likely to experience difficulties in emotion regulation (p<0.05). The results underscore the impact of social anxiety and emotional challenges during adolescence on psychological well-being and highlight the importance of intervention programs aimed at fostering emotional and social development among adolescents. These findings can serve as a resource for future research and practical applications, contributing to the development of strategies to reduce social anxiety in adolescents.Öğe Are the Notions of Leader–Member Exchange and Organisational Citizenship Effective in Enhancing Teachers’ Job Performance in Türkiye? A Moderated Mediation Model(MDPI AG, 2025-01-02) Mehmet Sabir ÇevikThis study is correlational and cross-sectional quantitative research that examines the moderating role of working time with the school principal on the effect of leader-member exchange on teachers' job performance through organisational citizenship. Data were collected from 481 teachers in 43 public schools across the western, central, northern, southern, and eastern regions of Türkiye using the convenience sampling method. The Leader-Member Exchange Scale, Organisational Citizenship Scale, and Employee Performance Scale were used as data collection tools. Data were analysed through descriptive analyses, Pearson correlation analysis, and moderator and moderated mediation analyses. The results indicated positive and significant relationships among leader-member exchange, organisational citizenship behaviours, and teachers' job performance. It was found that leader-member exchange indirectly affected teachers' job performance through organisational citizenship, and working time with the school principal served as a moderator in the relationship between leader-member exchange and organisational citizenship. The indirect effect of leader-member exchange on job performance through organisational citizenship was stronger for teachers with shorter working durations with the principal.Öğe Is there a significant relationship between the empowering leadership behaviors of school principals and the psychological resilience of teachers? Understanding the moderating effects of gender and length of time spent with the school principal(Springer Science and Business Media LLC, 2025-01-08) Mehmet Sabir Çevik; Emine DoğanThe psychological resilience of teachers has gained significant attention due to its positive effects on schools and students. This cross-sectional quantitative study investigates the moderating roles of gender and the length of time spent with the school principal in the relationship between principals' empowering leadership behaviors and teachers' psychological resilience. Data were collected from 362 teachers working in public primary, secondary, and high schools in Siirt, T & uuml;rkiye. Descriptive statistics, correlation analysis, and moderation analysis using the bootstrapping method were applied to analyze the data. The findings reveal that the empowering leadership behaviors of school principals positively correlate with teachers' psychological resilience, with variations based on gender and time spent with the principal. Specifically, the relationship is stronger for female teachers compared to male teachers and for those who have spent more time with the school principal. These results offer theoretical insights and practical recommendations for enhancing teacher resilience through leadership practices, highlighting the importance of understanding contextual and demographic factors.
