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    The mediating role of career concerns between career goal inconsistency, alienation and loneliness
    (Frontiers Media Sa, 2025) Ozman, Cemal; Ugras, Sinan; Sagin, Ahmet Enes; Yucekaya, Mehmet Akif; Eyuboglu, Ender; Daskesen, Sonay Serpil
    Uncertainty and inconsistency in career goals can weaken students' psychosocial adjustment. While the existing literature reports a link between this situation and loneliness and alienation from university, evidence on how these connections develop, particularly among sports science students, is limited. This study examined the mediating role of career concerns in the relationship between career goal inconsistency, loneliness, and university alienation. The study included 631 students from the sports science faculty in T & uuml;rkiye. Validated self-report scales were used to measure the variables. The mediation analysis was carried out through the JASP 0.16.4 statistical program using structural equation modelling and bootstrap procedures. The tested model was confirmed. Career goal inconsistency positively associated with career concerns (beta = 0.46, p < 0.001), loneliness (beta = 0.21, p < 0.001), and alienation from university (beta = 0.26, p < 0.001). Career concerns also associated with loneliness (beta = 0.17, p < 0.001) and alienation (beta = 0.15, p < 0.001). Indirect associations were significant for the paths from career goal inconsistency to loneliness (beta = 0.08, p < 0.001) and to alienation (beta = 0.07, p = 0.001) through career concerns. The explained variances were R-2 = 0.36 for career concerns, R-2 = 0.16 for loneliness, and R-2 = 0.20 for alienation. These findings suggest that inconsistencies in career goals are associated with increased students' career anxiety, loneliness, and alienation from university, both directly and indirectly. Therefore, it is important to provide career counselling and guidance services that reduce students' anxiety and strengthen their sense of belonging to the university, especially in fields such as sports sciences, where career paths are often uncertain.
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    Öğe
    Varying doses of evening caffeine ingestion have different effects on rowing ergometer performance, sleep quality, and wakefulness scores
    (Frontiers Media Sa, 2025) Karakulak, Izzet; Yildirim, Ulas Can; Erkan, Dilara; Karayigit, Raci; Eyuboglu, Ender; Diedhiou, Azize Bingol; Gundem, Mehmet Can
    Introduction: This study investigated the dose-dependent effects of evening caffeine ingestion on rowing performance, sleep quality, and daytime sleepiness in trained male rowers. Methods: Using a double-blind, randomized, crossover design, 13 university-level rowers (mean age = 22.07 +/- 2.21 years; mean body mass = 77.66 +/- 6.45 kg) completed four 2,000 m time-trial sessions between 19:00 and 20:00 h under placebo (PLA), low-dose capsule caffeine (3 mg/kg, LDC), moderate-dose capsule caffeine (6 mg/kg, MDC), and high-dose capsule caffeine (9 mg/kg, HDC) conditions. Performance metrics, heart rate, and subjective sleep assessments were collected. Rowing performance was assessed by a standard 2,000 m rowing ergometer (Concept II, United States) time trial. Sleep quality was measured with a numerical rating scale in the morning after each trial, and daytime sleepiness was measured with the Karolinska Sleepiness Scale. Results: Results indicated significantly improved rowing times and power output with HDC and MDC compared to PLA (p < 0.05), with HDC yielding the most notable enhancements (d = 0.40-0.41). However, these ergogenic benefits were accompanied by significantly impaired sleep quality and elevated daytime sleepiness in both HDC and MDC groups (p < 0.01; d = 1.3-1.5). Notably, adverse effects such as headache, insomnia, and gastrointestinal discomfort were predominantly reported in the HDC condition (p < 0.05). Although LDC offered mild performance improvements with minimal sleep disruption, only the high dose condition exhibited large physiological and perceptual trade-offs. Discussion: These findings indicate a clear dose-response relationship, wherein higher evening caffeine intake improves performance but has detrimental effects on sleep and recovery markers. Coaches and athletes should carefully balance caffeine dosing against potential recovery costs, especially in evening training or competition contexts.