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    Caffeine Habituation, Not CYP1A2 Genotype, Modulates the Acute Effect of Caffeine on Exercise-Induced Hemostatic Responses in Adults with Obesity
    (Lippincott Williams & Wilkins, 2025) Sajedi, Heidar; Aydin, Elif; Keskin, Ozlem; Ercis, Sertac; Akpinar, Selahattin; Khodadadi, Davar
    Purpose: This study aimed to investigate how genotype and caffeine habituation influence the acute effects of caffeine ingestion on exercise-induced hemostatic responses in individuals with obesity. Methods: Using a randomized, double-blind, placebo-controlled crossover design, 40 physically inactive young men with obesity (age, 22.2 +/- 2.3 yr; body mass index, 34.1 +/- 2.7 kgm(-2)) completed two moderate-to-high-intensity concurrent exercise sessions following ingestion of caffeine (3 mgkg(-1)) or placebo. Blood samples were collected at baseline, after exercise, and after 60 min of recovery. Statistical analysis was performed by repeated-measures multivariate analysis of variance. Results: Acute exercise increased platelet count and aggregation, fibrinogen, F1 + 2, tPA antigen, D-dimer, and clot lysis time, regardless of genotype or caffeine habituation status (P < 0.05). PAI-1 antigen remained unchanged after exercise (P > 0.05) but decreased following recovery (P < 0.01). Caffeine resulted in a greater increase in platelet aggregation, fibrinogen, F1 + 2, and clot lysis time, alongside a blunted increase in tPA antigen levels post-exercise in na & iuml;ve consumers (P < 0.05). In contrast, habitual caffeine consumers exhibited a mitigated increase in clot lysis time and a greater post-recovery reduction in PAI-1 antigen following caffeine ingestion (P < 0.001). Caffeine's impact on hemostatic responses to exercise was unaffected by genotype (P > 0.05). Conclusions: Moderate-to-high-intensity concurrent exercise induces a transient prothrombotic state in physically inactive individuals with obesity. Acute caffeine supplementation at a moderate dose modulates the hemostatic responses depending on caffeine habituation status rather than CYP1A2 genotype: it exacerbates the prothrombotic response in na & iuml;ve consumers but attenuates it in habitual consumers.
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    Fasted-State Aerobic Exercise Enhances Cognition and Hippocampal BDNF Signaling in an Alzheimer's Disease Rat Model
    (Springer/Plenum Publishers, 2025) Kirkbir, Fatih; Atasoy, Taner; Khodadadai, Davar; Sajedi, Heidar; Keskin, Ozlem; Babaie, Mohammad
    Alzheimer's disease (AD) is a multifactorial disorder that demands a comprehensive management strategy. Both aerobic exercise training and intermittent fasting (IF) have been shown to ameliorate AD symptoms, yet the impact of exercise in the fasted state remains understudied. This study compared the effects of four weeks of moderate-intensity treadmill running in either a fasted or a normal fed state on cognitive function and hippocampal BDNF signaling in an amyloid-beta (A beta)(1-42)-injected rat model of AD. Twenty-month-old male Wistar rats were allocated into five groups (n = 12 each): AD, AD plus IF (ADIF), AD plus exercise training (ADET), AD plus IF plus exercise training (ADIFET), and control. AD was induced by bilateral intra-hippocampal A beta(1-42) injection. Exercise interventions (fasted or fed) were conducted 5 days/week for 4 weeks. A beta injection significantly impaired learning and memory and reduced hippocampal levels of PKA, CREB, and BDNF (p < 0.001). Both fasting and exercise independently elevated plasma and hippocampal beta-hydroxybutyrate (beta HB) (p < 0.001), with the highest beta HB increase observed in the fasted-exercise group (p < 0.01). All intervention groups (ADIF, ADET, and ADIFET) demonstrated significant improvements in cognitive performance and hippocampal levels of PKA, CREB, and BDNF (p < 0.001). The combined fasting plus exercise group produced greater benefits than either IF or exercise alone (p < 0.05), and exercise alone outperformed fasting alone (p < 0.05). These findings indicate that aerobic exercise in the fasted state offers superior neuroprotective and cognitive benefits, likely via upregulation of beta HB/PKA/CREB/BDNF signaling, highlighting fasted-state exercise as a promising therapeutic approach for AD.
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    FROM TOKYO TO LOS ANGELES: MODELING OLYMPIC OUTCOMES IN WOMEN'S ARTISTIC GYMNASTICS
    (Univ Ljubljana Press, 2026) Keskin, Ozlem
    Performance in women's artistic gymnastics is evaluated through difficulty (D) and execution (E) scores across four apparatuses: Vault, Uneven Bars, Balance Beam, and Floor Exercise. Understanding how these scores predict overall success can guide athlete development and Olympic preparation. This study aimed to identify key predictors of all-around performance and project future trends by analyzing official Olympic data. Final scores from the all-around competitions at the Tokyo 2020 (n = 80) and Paris 2024 (n = 58) Olympic Games were used to construct multiple linear regression models. Apparatus-specific D and E scores served as independent variables to predict total scores. Separate models were developed for each Olympic cycle and for the combined dataset. All models demonstrated excellent predictive strength (R2 > 0.998). Among the predictors, E scores-particularly on Uneven Bars and Balance Beam- showed the strongest contributions to total scores (beta > 0.25, p < .001). The combined model exhibited strong internal consistency and minimal multicollinearity, supporting its robustness and generalizability. Trend-based analysis indicated a continued increase in average total scores between 2020 and 2024, suggesting further gains toward the 2028 Los Angeles Games. These findings underscore the critical role of execution quality, especially on technical apparatuses, and support the strategic use of longitudinal performance modeling in elite gymnastics training. Coaches and sport scientists may benefit from focusing on apparatus-specific E score optimization to enhance Olympic performance outcomes.
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    Levels of psychological well-being in category footballers U16 - U19
    (Univ Peruana Union, 2022) Akdeniz, Hakan; Keskin, Ozlem; Kavi, Onur; Kaya, Alim Can
    This study was performed with the aim of investigating the psychological well-being levels of adolescent sportmen in accordance with a number of variables by using the general survey model. The target population of the study composed of 196 sportmen who played soccer for youth setup of amateur football club located in Kocaeli. Within the scope of the study, personal information form and Psychological Well Being Scale were used as data collection tools. In testing of the hypothesis, Pearson Correlation and One-way ANOVA was exerted. In this the study, a significant difference was observed by means of sub-dimensions that can be listed as autonomy, environmental mastery, personal growth, positive relations with others, purpose in life and self-acceptance (p<0,05). it can be commented that the performance of adolescent footballer's alternates in accordance with their psychological well-being levels in terms of different teams. When the performance of adolescent footballers was evaluated according to psychological well-being levels, no significant difference was observed (p>0,05). As a result of league levels, league positions and monthly a significant difference was observed (p<0,05). When the collected data were interpreted, it can be stated that performance and psychological well-being levels of sportsmen show and alteration with regard to league levels, league positions, and monthly household income.
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    Managing emotions in amateur soccer players: a case study
    (Univ Peruana Union, 2021) Akdeniz, Hakan; Sekban, Gulsah; Keskin, Ozlem; Turedi, Okan
    This research aimed to review trait anger-anger expression styles of footballers who play in amateur football clubs in Pendik district of istanbul Province by certain variables. Entirely 100 male footballers who play in 7 different amateur football clubs participated in this research. Trait Anger-Anger Expression Style Scale that was developed by Spielberger et all., (1983) and demographic information form were used to collect the data. Descriptive statistical methods, Pearson Correlation and ANOVA test were used to evaluate the data. According to analyzed results, there was no statistically significant difference (p>0,05) among trait anger, anger-in anger-out, anger management and total anger scores based on footballers' educational background, age ranges, sporting years and the clubs. On the other hand, there was a positive significant relationship between trait anger and anger-in, between trait anger and anger-out. A negative significant relationship was found between anger management and trait anger. Moreover, a negative significant relationship between anger-out and anger management. In conclusion, it can be said that as the anger level increases, anger-in and anger-out level of footballers' increase; however, anger management decreases at the same time. As the angerout increases, anger management of footballers decreases.