Kadir Keskin

Isometric and dynamic contraction protocols are commonly used in sports to achieve post-activation performance enhancement (PAPE). Although rest intervals in PAPE protocols have been widely investigated, the effects of different PAPE methods on performance across recovery intervals remain unclear. Therefore, this study aimed to examine the effects of post-activation potentiation induced by different contraction types on change-of-direction performance under varying rest durations. Twenty male soccer players (age: 20.9 ± 1.3 years; training experience: 7.6 ± 2.7 years; height: 176.9 ± 5.7 cm; body weight: 74.3 ± 7.5 kg) voluntarily participated in this study. The study used a randomized, crossover design, with 48-hour intervals over three non-consecutive days. On the first day, anthropometric characteristics and one-repetition maximum (1RM) knee extension performance were assessed. Following a standardized warm-up protocol, change-of-direction (CoD) test performance was recorded on the second and third days. After a 5-minute passive rest, participants performed either a dynamic (1 set of 3 repetitions at 90% 1RM) or an isometric (3 sets of 3 seconds, with 2-minute rest intervals) knee extension protocol. Subsequently, CoD tests were conducted at 15 seconds, 3, 6, 9, and 12 minutes post-activation. No significant main or interaction effects were observed for contraction type or recovery interval (p > .05). Furthermore, no significant differences in rest intervals were observed between the isometric and dynamic protocols (F = 1.383, p = .255, ηp2 = .061). In conclusion, these results indicate that neither the isometric nor the dynamic exercise protocols produced a pronounced PAPE effect on CoD performance.

Bu çalışma, Kerkük yöresi geleneksel oyunlarından Hellük ve Mehelle Kırma oyunlarını araştırmak, kayıt altına almak ve Türkiye’deki varyantlarıyla karşılaştırmak amacıyla gerçekleştirilmiştir. Veriler, Kerkük’te yaşayan ve bu oyunları bilen 10 yetişkin bireyle, yarı yapılandırılmış görüşme formu kullanılarak yapılan görüşmeler sonucu elde edilmiştir. Oyunların Türkiye’deki varyantları hakkındaki verilere ise doküman analizi yöntemi kullanılarak literatür taraması yoluyla ulaşılmıştır. Görüşmelerden önce katılımcılara araştırmanın amacı hakkında bilgi verilmiş ve etik kurallar çerçevesinde, gönüllülük esasına dayalı olarak katılımları sağlanmıştır. Elde edilen veriler betimsel analiz yöntemiyle analiz edilmiş ve Hellük ve Mehelle Kırma oyunları detaylı bir şekilde kayıt altına alınarak Türkiye’de oynanan varyantları ile benzerlik ve farklılıkları karşılaştırılmıştır.

Athletic performance is a complex genetic trait influenced by environmental interaction and genetic make-up. The α actinin-3 protein encoded by the ACTN3 gene might be associated with athletic status. The aims of this study were to evaluate the differences in the genotype distribution of the ACTN3 R577X polymorphism in elite Turkish wrestlers, football players, and endurance runners and to investigate whether this polymorphism is associated power/strength (wrestling and football) and endurance-based athletes (endurance running) with athletic performance. 53 wrestlers, 71 football players, 34 endurance runners, including 56 controls were participated to this study. Genotyping of ACTN3 R577X polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism method. The ACTN3 genotype frequencies of athletes were 37.7% RR, 52.8% RX, and 9.4% XX for wrestling, 43.7% RR, 40.8% XX, and 15.5% XX for fooball players, and 32.4% RR, 47.1% RX, and 20.6% XX for endurance running. To establish the differences in the genotype distribution and allelic frequency of the ACTN3 R577X were compared elite Turkish athletes with controls, and power/strength with endurance-based athletes. No significant difference was observed among athlete cohorts (p>0.05). Our findings verified that although there are many diverse over metabolic and mechanical determinants, the ACTN3 gene is similar over distinct types of sports disciplines, such as wrestling, endurance running and soccer.

Introduction: Thermal imaging technology provides detailed insights into the skin temperature patterns and asymmetries of athletes, offering valuable data to enhance performance, assess the effectiveness of rehabilitation, monitor fatigue, and prevent injuries. Methods: The aim of this study was to assess acute skin temperature responses before and after the 30-15 Intermittent Fitness Test in professional male soccer players. Twenty-one professional soccer players performed a 30-15 IFT, and the running time, peak velocity, and true velocity were calculated. Thermal images of the players were acquired using an infrared thermal camera before and immediately after the 30-15 IFT, and skin temperature measurements were analyzed from the anterior thigh, anterior leg, posterior thigh, and posterior leg. Results: The skin temperature asymmetries differed significantly between all regions of interest, with the greatest difference in the anterior and posterior thighs. Pearson correlation analysis revealed that the 30-15 IFT parameters were not correlated with the posttest skin temperature asymmetry for any of the region of interests. However, there were significant negative correlations between pretest skin temperature asymmetry in the posterior leg region and all 30-15 IFT parameters for running time (r=0.30; p<.05), peak velocity (r=0.3; p<.05), and true velocity (r=0.25; p<.05). Finally, athletes with lower baseline skin temperature asymmetries in the posterior leg region have better 30-15 IFT performance. Conclusion: Thermal imaging can be used to assess muscular asymmetries following specific endurance tests or conditioning training, and this information can provide valuable information for optimizing performance and injury prevention.

The aim of this research was twofold: i) to investigate the relationship between leg circumference and limb occlusion pressure (LOP) by using an automated blood flow restriction (BFR) device, ii) to compare the LOP and leg circumferences between the dominant (D) and non-dominant (ND) legs. One hundred and four participants (age=20.79±2.47 years; height= 177.8±5.72 cm; body weight=73.74±13.24 kg) visited the laboratory for the testing session. D and ND leg circumferences were measured with a tape measure. After 10 minutes of resting, LOP was then assessed bilaterally in the supine position using an automated BFR device (Cuff width: 10 cm). Pearson’s correlation coefficient (r) was used to analyse the relationship between leg circumference and LOP values. A simple linear regression analysis was also conducted on the D and ND legs to determine the predictive relationship between leg circumference and LOP. Paired sample t-test was used to analyse differences for LOP and leg circumferences between D and ND legs. Moderate positive correlation was found between D and ND leg circumference and LOP (r=0.5937, p

Objective: This study aimed to identify the relationship between maximal oxygen uptake (VO2max) and Wingate Anaerobic Test (WAnT) parameters with movement parameters in a simulated futsal game. Methodology: Sixteen semi-professional futsal players participated in the study (26.8 ± 2.2 years). Statistical analyses included Pearson’s correlation, with the significance level set at p < 0.05. Results: VO2max presented a very strong significant correlation with low- (LIRD, r = 0.90, p = 0.001) and moderate-intensity running distance (MIRD, r = 0.97, p = 0.001), total distance (TD, r = 0.94, p = 0.001), and player load (PL from training impulse [TRIMP], r = 0.94 p = 0.001), moderate correlation with acceleration (ACC, r = 0.57, p = 0.022), and deceleration (DEC, r = 0.61, p = 0.012), whereas the velocity at anaerobic threshold (VAT) correlated strongly with MIRD (r = 0.81, p = 0.001) and PL (r = 0.84, p = 0.001), and moderately with LIRD (r = 0.60, p = 0.015) and TD (r = 0.66, p = 0.005). Peak and mean powers correlated with sprint distance (SD) and TD—strong to very strong correlations (r = 0.76 to 0.92, p = 0.001); whereas the minimum power significantly correlated with MIRD, SD, PL, ACC, and DEC—moderate to strong correlations (r = 0.51 to 0.72, p = 0.04 to 0.002). Conclusions: In conclusion, our findings suggest that VO2max effectively indicates long-duration, low-intensity activities in futsal players. Conversely, anaerobic peak power is a reliable indicator of high-intensity running distance and a significant predictor of sprinting ability.

This study aimed to investigate the acute effects of autoregulated and non-autoregulated blood flow restricted resistance exercise on Wingate anaerobic performance test metrics. Fifteen recreationally active male individuals (age: 19.67 ± 1.54 years; height: 179.3 ± 7.65 cm; weight: 76.04 ± 13.97 kg) were involved in the study. Subjects performed Wingate anaerobic tests before the experimental session and data were recorded as baseline measurements. Then, a randomised counterbalanced crossover design was adopted to compare the acute effects of autoregulated and non-autoregulated BFR by performing back squat exercise (40% 1RM, 4x15 reps). After completing the back squat exercise, subjects rested for fifteen minutes and performed Wingate anaerobic performance tests with resistance of 7.5% body mass. GraphPad Prism 10 was used to analyse the data. Significance was set at p < 0.05. No significant difference was found in Peak Power (W) F(2,42):0.1509, p:0.86, pη2:0.007 and Average Power (W) F(2,42):0.0014, p:0.99, pη2:0.00006 between conditions. No significant difference was found in Fatigue Index (%) F(2,42):0.9396, p:0.39, pη2:0.0042 and Power Drop(W) F(2,42):0.5860, p:0.56, pη2:0.027 between conditions. This study suggests that performing both autoregulated and non-autoregulated BFR did not show significant differences between the two conditions and compared to baseline test results. It should be noted that our study only looked at autoregulation in one specific device. Therefore, findings should be interpreted with caution, as they may not be representative of other BFR systems that use autoregulation modes.

The purpose of this study was to examine the impact of Life Kinetik (LK) exercises on balance, agility, jumping performance, proprioception, and cognitive functions in recreationally active preadolescents participating in fencing. The study lasted 8 weeks and included 22 preadolescents recreationally engaged in fencing, aged 11.6 ± 1.2 years, with an average weight of 49.5 ± 10.5 kg and an average height of 157.5 ± 10.0 cm. Preadolescents were randomly assigned to either the LK group or the control group. The experimental group participated in LK exercises twice per week, with each session lasting one hour. The results indicate that the changes in Stroop, agility, vertical jump, and proprioception test performance between the pre-test and post-test for the control group are not statistically significant. However, the LK group showed statistically significant improvements in Stroop, agility, and vertical jump performance between the pre-test and post-test (p < 0.001). Conversely, the change in proprioception test performance between the pre-test and post-test for the LK training group was not statistically significant. The changes in star balance test performance between the pre-test and post-test for the control group was not statistically significant. In contrast, the LK group showed a statistically significant improvement in star balance test performance between the pre-test and post-test (p < 0.001). These findings indicate that while LK exercises are effective in boosting overall athletic performance, they may not be sufficient for developing specific skills such as proprioception. The randomized controlled trial was registered on 04/01/2025 at ClinicalTrials.gov, under the registration number NCT06781268.

This study investigated the effect of limb occlusion pressure (LOP) position on exercise performance, cardiovascular responses, and perceptual experiences during seated bilateral leg extensions with and without blood flow restriction (BFR). Thirty resistance-trained males (age: 22 ± 2 years; weight: 74.4 ± 13.6 kg; height: 177.4 ± 6.4 cm; BMI: 23.5 ± 3.3 kg/m²) participated. Each performed exercise to failure (4 sets, 30% 1RM, 1 min rest) in three conditions: Supine LOP-BFR, Seated LOP-BFR, and no-BFR. BFR was applied at 60% LOP. Significant interaction effects were found for RPE (p = 0.021, d = 0.76), RPD (p < 0.01, d = 1.72), and DOMS (p < 0.01, d = 2.28). Statistically significant fewer repetitions were completed in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.5), Seated LOP-BFR vs. no-BFR (p < 0.01, d = 1.0), and Seated LOP-BFR vs. Supine LOP-BFR (p < 0.01, d = 0.6). RPE was higher in Seated LOP-BFR vs. no-BFR (p < 0.01, d = 0.52). RPD was higher in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.62) and Seated LOP-BFR vs. no-BFR (p < 0.01, d = 1.25). DOMS was higher in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.77) and Seated LOP-BFR vs. no-BFR (p < 0.01, d = 3.52). Seated LOP-BFR increased perceptual demands and reduced repetitions compared to Supine LOP-BFR. Both LOP-BFR conditions reduced repetitions compared to no-BFR without affecting cardiovascular measures.