Profile URL: https://hdl.handle.net/20.500.12514/7111
Job Title:Doçent
Main Affiliation:Department of Sports Magement / Spor Yöneticiliği Bölümü
ORCID:
0000-0003-0673-4796
0000-0003-0673-4796Scopus ID:
CYI-8257-2022
CYI-8257-2022YÖK Akademik: DF4A52415C39E967
Web of Science ID:
57208886121
57208886121Name Variants:
Karakulak, Izzet Karakulak, İzzet
20 results
Scholarly Output Search Results
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Article The Effects of Movement-Based Exercises Combined with Respiratory Techniques on the Thoracic Kyphosis Angle in Individuals with Thoracic Hyperkyphosis: A Systematic Review and Meta-Analysis(2026) Kirkbir, Fatih; Khazanin, Hossein; Karakulak, İzzet; Delavari, Mohammad; Yilmaz, Fatih; Solana–tramunt, Mònica; Moazamigoudarzi, ShadiBackground: Thoracic hyperkyphosis (THK) is a postural deformity associated with pain, impaired respiratory function, reduced quality of life, scapular rhythm impairment, shoulder biomechanical alterations, and increased fall risk. While corrective exercises are commonly used, the added value of integrating specific respiratory techniques remains unclear. This systematic review and meta-analysis aimed to evaluate the effects of movement-based exercises combined with respiratory techniques on the thoracic kyphosis angle (TKA) in individuals with THK. Methods: A systematic search of PubMed, Scopus, Web of Science, CINAHL, SPORTDiscus, PEDro, and CENTRAL Cochrane Library was conducted from inception to 16 July 2026. Randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) investigating combined exercise and respiratory interventions in individuals with THK were included. The primary outcome was TKA. Two authors independently selected studies, extracted data, and assessed quality, with a third author resolving discrepancies. Risk of bias was assessed using RoB-2 for RCTs and ROBINS-I for non-RCTs. Certainty of evidence was graded using GRADE. A random-effects meta-analysis of TKA was performed using Hedges’ g. Results: Five studies involving 247 participants were included. Meta-analysis demonstrated a significant reduction in TKA following combined intervention compared with exercise alone (Hedges’ g = 0.667, 95% CI: 0.395 to 0.940, p < 0.001; I2 = 39.7%). Subgroup analysis by age group revealed significant improvement in adolescents (Hedges’ g = 0.860, 95% CI: 0.532 to 1.189, p < 0.001; I2 = 0%) but no significant effect in older adults (Hedges’ g = 0.241, 95% CI: −0.247 to 0.729, p = 0.333; I2 = 0%). The certainty of evidence for TKA was graded as moderate, with downgrading for risk of bias, indirectness, and potential publication bias. Conclusions: Movement-based exercises combined with respiratory techniques significantly improve thoracic alignment in individuals with THK, with moderate certainty evidence, particularly in adolescents. The evidence in older adults remains inconclusive due to limited studies and structural factors. Larger, high-quality, and standardized trials are needed to confirm these effects, establish optimal treatment parameters, and evaluate long-term outcomes across diverse populations.Article Move in Nature, Get Strong with Smart Sports: Physical Activity Habits and Health-Related Psychological Factors among Adults Exercising in Green and Smart Sports Environments(Frontiers Media SA, 2026) Ulukan, Mahmut; Karakulak, İzzet; Tunçer, Mehmet; Rüzgar, Kerim; Ceylan, Levent; Sari, Okan; Bingölbalı, NisanurIntroduction Sedentary lifestyles threaten physical and psychological well-being. Nature-integrated green sports environments and digitally supported smart sports environments may promote physical activity and sustainable health. This study examined the direct and indirect associations among green facility exposure/use, smart facility/technology interaction, physical activity, sport motivation, perceived stress, psychological resilience, and quality of life. Methods A quantitative, cross-sectional correlational design was used with 300 adults living in Türkiye (168 women and 132 men; mean age = 33.4 years, SD = 9.7). Data were collected online between 22 May and 14 November 2025 and analyzed using a hybrid structural equation model combining observed composite indices and latent psychometric constructs. Results The model showed acceptable fit ( χ 2 /d f = 2.10, CFI = 0.96, TLI = 0.95, RMSEA = 0.051, SRMR = 0.044). Physical activity was positively associated with sport motivation ( β = 0.48, p < 0.001), which was positively associated with psychological resilience ( β = 0.42, p < 0.001) and quality of life ( β = 0.27, p < 0.001). Green facility exposure/use ( β = 0.18, p < 0.05) and smart facility/technology interaction ( β = 0.12, p < 0.05) were positively associated with physical activity. Perceived stress was negatively associated with psychological resilience ( β = −0.33, p < 0.01) and quality of life ( β = −0.29, p < 0.01). Indirect associations linked physical activity with quality of life through sport motivation and psychological resilience. Discussion Green and smart exercise contexts may support physical activity and related motivational and psychological processes. Because the study was cross-sectional, the findings should be interpreted as associations rather than causal effects. Nature-based and technology-supported opportunities may inform sports-environment planning and public-health strategies.Article Identification of the Relationship Between Life Satisfaction and Narcissism Levels of University Students(2020) Karakulak, İzzet; Tazegül, ÜnsalThe objective of this study is to identify the relationship between life satisfaction and narcissism levels of students of the Physical Education and Sports School of Mardin Artuklu University located in southeastern Turkey. In the study, Satisfaction with Life Scale and Narcissistic Personality Inventory were employed in order to collect data. Sample of the study is comprised of a total of 155 Physical Education and Sports School students who voluntarily agreed to participate in the study. 56 participants were female and 99 participants were male. In the data analysis of this research, SPSS 20.0 software was utilized. Independent Samples T-Test, One-way Analysis of Variance (ANOVA) and correlation analysis were used in data analysis. At the end of the statistical analysis, it was found that female students had quantitatively higher narcissistic personality and life satisfaction scores than male students. Thus, it was inferred that female students behaved more narcissistically and were more engaged with life. However, along with the comparison of students’ narcissism and life satisfaction scores particularly on the basis of departments of Physical Education and Sports School at which students were enrolled, it was ascertained that there was no statistically significant difference in either narcissism scores or life satisfaction scores.Article Investigation of Pre-Competition State Anxiety Levels of Athletes(2025) Yavaş, Özge; Karakulak, İzzetThis study analysed the pre-competition levels of cognitive anxiety (CA), somatic anxiety (SA) and self-confidence (SC) of athletes in various sports. The sample consisted of 277 athletes (92 females, 185 males) aged 15–34, selected through non-probability sampling. Data were collected using the Revised Competition State Anxiety Inventory-2 (CSAI-2R), a 4- point Likert scale measuring CA, SA, and SC, administered 30 minutes before competition. Results revealed that male athletes had higher SC levels than females. Athletes who participated in national competitions had lower SC levels compared to those who did not, while no significant difference was found for international competition participation. Agerelated differences were observed: CA levels were higher in athletes aged 15–19 compared to those aged 30–34, and higher in athletes aged 25–29 than in those aged 20–24 and 30–34. Volleyball players exhibited lower CA levels than football and athletics athletes. Athletes with 2–5 years of experience had lower SC than those with 10–17 years of experience, and athletes with 14–17 years of experience had higher SC than those with 6–9 years. No significant differences were found based on weekly training frequency. The study highlights significant variations in state anxiety among athletes based on age, gender, sport type, and experience. It underscores the need for enhanced sports psychology training for athletes and coaches to reduce anxiety and improve psychological awareness, ultimately optimizing performance.Master Thesis Gençlik ve Spor Bakanlığına Bağlı Mardin Yurtlarında Kalan Üniversite Öğrencilerinin Spora Yönelik Farkındalıklarının Demografik Değişkenlere Göre İncelenmesi(2025) Akalan, Murat; Karakulak, İzzetBu araştırmanın amacı, Mardin ilindeki Gençlik ve Spor Bakanlığına bağlı yurtlarda kalan üniversite öğrencilerinin spora yönelik farkındalık düzeylerini belirlemek ve bu düzeylerin demografik değişkenlere göre (cinsiyet, yaş, öğrenim görülen bölüm, sınıf düzeyi, spora katılım durumu, ailede sporla uğraşan bireylerin varlığı) farklılık gösterip göstermediğini incelemektir. Araştırmanın örneklemini, Mardin GSB yurtlarında kalan toplam 666 üniversite öğrencisi oluşturmaktadır. Veri toplama aracı olarak Uyar (2019) tarafından geliştirilen 'Spor Farkındalığı Ölçeği (SFÖ)' kullanılmıştır. Araştırma betimsel tarama modeli ile desenlenmiş ve elde edilen veriler SPSS 25.0 programında analiz edilmiştir. Verilerin analizinde bağımsız gruplar t-testi ve tek yönlü varyans analizi (ANOVA) kullanılmıştır. Bulgular öğrencilerin genel olarak orta düzeyde spor farkındalığına sahip olduklarını göstermektedir. Cinsiyet, bölüm, sınıf düzeyi, sporla ilişki ve ailede sporla uğraşan demografik değişkenleri incelendiğinde spor farkındalık düzeyi üzerinde anlamlı farklar yarattığı ancak yaş demografik değişkeninde anlamlı bir farkındalık bulunmadığı tespit edilmiştir. Sonuç olarak, GSB yurtlarında kalan öğrencilerin spora yönelik farkındalıklarının artırılmasına yönelik müdahale programlarının geliştirilmesi önerilmektedir. Anahtar Kelimeler: Spor farkındalığı, üniversite öğrencileri, demografik değişkenler, MYS yurtları, spor.Article Citation - WoS: 1Citation - Scopus: 1The Effect of Low Dose Caffeine Powder Supplementation on Serve Speed, Spike Speed, and Speed-Endurance in Elite Sitting Volleyball Players: A Randomized Double-Blind Crossover Study(BMC, 2025-11-06) Diedhiou, Azize Bingol; Erkan, Dilara; Guler, Melek; Sar, Halit; Karakulak, Izzet; Eyuboglu, Ender; Yildirim, Ulas CanBackgroundSitting volleyball relies heavily on upper-body strength and anaerobic capacity. Serve, spike, and speed-endurance are decisive skills, yet the ergogenic potential of low-dose caffeine in this Paralympic sport remains unclear.PurposeTo examine the acute effects of low-dose caffeine (3 mg/kg) supplementation on serve speed, spike speed, and speed-endurance in elite sitting volleyball players.MethodsUsing a randomized, double-blind, crossover design, 13 elite male athletes from the Turkish National Sitting Volleyball Team completed serve speed, spike speed, and speed-endurance tests under caffeine (CAF) and placebo (PLA) conditions.ResultsCaffeine intake produced a moderate improvement in serve speed (p = 0.028, d = 0.460); however, this effect did not remain statistically significant after Bonferroni correction (adjusted p = 0.084). No significant effects were observed for spike speed (p = 0.547, d = 0.166) or speed-endurance performance (p = 0.709, d = 0.111). Perceived exertion during the speed-endurance test was similarly high in both conditions.ConclusionsLow-dose caffeine may offer a trend toward improved serve performance, but the effect was not robust after statistical adjustment, and no benefits were observed for spike speed or speed-endurance. These findings highlight that caffeine's ergogenic effects are context-dependent and shaped by task complexity and sport-specific motor demands. Further research with larger and more diverse samples, genotype-based subgroups, and varied dosing strategies is warranted to clarify caffeine's role in adaptive sports.Trial registrationThe randomized controlled trial was retrospectively registered on 21/06/2025 at ClinicalTrials.gov, under the registration number NCT07056231.Article Acele Deneyimlerinin Ölçülmesi (Rush Experiences Scale-RES): Türk Kültürü İçin Geçerlik ve Güvenilirlik Çalışması(2025-09-22) Karakulak, İzzet; Tez, Özge Yavaş; Celebı, Murat; Eyuboglu, EnderAcele deneyimi kavramı ilk olarak macera turizmi alanına (Buckley, 2012) yakın zamanda (Tez, 2023) ise ciddi serbest zaman literatürüne dahil edilmiştir. Araştırmada, ciddi serbest zaman katılımcılarının “acele deneyimlerini” değerlendirebilecek kısa bir psikometrik ölçüm aracının Türk kültürü için adaptasyon çalışmasını gerçekleştirmektir. Bu bağlamda, araştırma ciddi serbest zaman katılımına ilişkin katılımcılarının acele deneyimlerini değerlendirebilecek ulusal alanda ilk nicel ölçüm aracını sunmaktadır. Araştırmanın evren ve örneklemini Türkiye’de yer alan ciddi serbest zaman katılımcıları (macera-yüksek riskli sporcular ve ekstrem sporcular) oluşturmaktadır. Araştırmada ölçüt örnekleme yöntemi kullanılmıştır. Veriler çevrimiçi oluşturulan formlar aracılığıyla toplanmıştır. Ayrıca araştırmada örnekleme yöntemi olarak hem ölçüt hem de kartopu örnekleme yöntemi birlikte kullanılmıştır. Ciddi serbest zaman katılımcılarından toplanan veriler ile yapının doğrulanması için DFA analizi yapılmıştır. Ek geçerlilik ve güvenirlik analizleri için AVE ve CR değerleri hesaplanmıştır. Ölçüm güvenirliği için Cronbach Alpha değeri hesaplanmıştır. Ayrıca katılımcıların verdikleri cevaplara ilişkin taban ve tavan etkileri analizleri yapılmıştır. 13 maddeden oluşan tek faktörlü bir yapıya sahip olan Acele Deneyim Ölçeği' nin (RES) faktör yapısının Türk kültüründe doğrulanması amacıyla gerçekleştirilen DFA sonucunda uyum indeksi χ2/sd = 3,081, RMSEA = 0.06, GFI = 0.94, AGFI = 0.90, IFI = 0.93, NFI = 0.90, TLI = 0.89 ve CFI = 0.93 olarak belirlenmiştir. DFA ile Türk kültürü için faktör yapısı doğrulanan Acele Deneyimi Ölçeği 13 madde tek faktörlü yapısı ile geçerli ve güvenilir ölçmeler yapabilen bir ölçüm aracı olarak kabul edilebilir.Article FUTBOLDA MERKEZ VE KENAR OYUNCULARININ FİZİKSEL VE MOTORİK ÖZELLİKLERİNİN KARŞILAŞTIRILMASI(2019-06-30) Karakulak, İzzet; Eyuboğlu, Ender; Aslan, Cem SinanBu çalışmada amaç; “merkez ve kenar oyuncusu” olarak ayrılmış bir grup amatör futbolcunun seçilmiş fiziksel ve motorik özelliklerini karşılaştırmaktır. Çalışmaya yaşları 18 ila 31 arasında değişen 55 erkek amatör futbolcu katılmıştır. Katılımcılar “merkez veya kenar oyuncusu” olarak genel bir mevkisel ayrıma tabii tutularak iki gruba ayrılmışlardır. Katılımcıların vücut kompozisyonları, alt ekstremite kuvvetleri, anaerobik güçleri, aerobik dayanıklılıkları, sürat ve esneklik değerleri saha testleri ile belirlenmiştir. Elde edilen veriler normal dağıldığından, grupların karşılaştırılmasında SPSS (Ver.14) programında yer alan Independent Sample t Test kullanılmış, yanılma düzeyi 0,05 olarak kabul edilmiştir. Gruplar arasında yaş açısından fark yokken, boy, vücut ağırlığı, vücut kitle indeksi ve vücut yağ oranında anlamlı fark çıkmıştır. Motorik özelliklerden bacak kuvveti, esneklik ve 10 m sprint değerleri arasında fark oluşmazken dikey sıçrama, anaerobik güç, 30 m sprint ve VO2maks değerlerinde anlamlı fark oluşmuştur. Karşılaştırma sonuçları değerlendirildiğinde; merkez oyuncular boy uzunluğu, vücut ağırlığı, vücut kitle indeksi ve vücut yağ oranında kenar oyuncularından daha yüksek değerlere sahiptir. Motorik özelliklerde ise; kenar oyuncuları dikey sıçrama, 30 m sprint ve VO2maks bakımından daha iyi değerlere sahipken, merkez oyuncularının anaerobik güçleri daha fazladır.Article Citation - WoS: 2Citation - Scopus: 2Determination of Running Performance in Young Soccer Players(Mattioli 1885, 2020) Karakulak, IzzetStudy Objectives: This study aimed to determine the relationship between running performances in young soccer players and various parameters. Methods: The study was conducted with 20 male athletes from the U-14 youth setup soccer team of a sports club playing in the Turkish Football Super League. Various measurements were made to determine athletes' height, body weight, leg, lower leg and upper leg length, leg force, active and squat jump heights, sprint times in 15, 20, 25, 30, 35, and 40 meters. The videos, on which athletes' two full stride lengths where they reached maximal speed were recorded, were analyzed on Ariel Performance Analysis System (APAS) package program the with below-waist analysis method, and their stride lengths on maximal speed were found. Thus, athletes' step frequencies were found by dividing their running times into their stride lengths. Data were evaluated on SPSS 22.0 package program with descriptive statistics and Spearman's rank correlation coefficient to determine the correlation between stride length and step frequency, and other parameters. Results: The results of statistical analyses showed that there was a negative medium level correlation between stride length and sprint time in 15m (r = -.484) while there was a negative strong correlation between stride length and step frequency (r = -.880). There was a positive strong correlation between step frequency and sprint time in 15m (r =.751), 20m (r =.691), 25m (r =.632) and 40m (r =.635) while a positive medium level correlation with sprint time in 35m (r =.460). Conclusion: Stride length is more determinative than step frequency especially in short distance races in terms of running performance in young soccer players.Article 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; Akca, FiratIntroduction: 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.