The correct torque ratio between the knee joint extensor and flexor muscle groups can effectively prevent injuries to the anterior cruciate ligament and hamstring strain. However, it is unclear whether a high torque ratio of the knee joint flexor muscles to the extensor muscles is beneficial for sport performance. Therefore, the aim of the study was to investigate the relationship between the hamstring-to-quadriceps (H/Q) ratio and sprint times (10- and 30-m) and jump heights (CMJ—countermovement jump and SJ—squat jump) in soccer players. The study examined 26 young elite soccer players (age: 18.1 ± 0.7 years; body height: 1.77 ± 0.05 m; body mass: 72.7 ± 5.7 kg). Knee joint flexor and extensor peak torques were assessed using the Cybex dynamometer (at 60°/s, 120°/s and 180°/s). Additionally, each participant performed the CMJ, SJ, and 30 m sprint. A significant relationship was obtained between the H/Q ratio (60°/s) and 30 m sprint time (r = 0.47). The positive direction of this relationship may indicate an important role of knee joint extensors in sprinting performance. Moreover, the H/Q ratio was not significantly associated with the CMJ, SJ or 10 m sprint performance. The H/Q ratio should be considered together with the peak torque values in terms of the assessment of sprinting and jumping performance.

Background and Study Aim. Sprint performance plays a major role in success of field-based team sports such as soccer. The aim of this study was to evaluate the relationship between sprinting performance and both lower and upper extremity explosive strength in young soccer players. Material and Methods. One hundred forty-seven soccer players (mean±SD; age 11.6±1.66 years, height 143.2±11.8 cm, body mass 37.1±10.2 kg and training experience 1.11±1.5 years) voluntarily participated in this study. The sprinting performance of each player was determined using their 5, 10, 20 and 30m single sprint times. The lower and upper extremity explosive strength were evaluated by standing long jump and medicine ball throwing tests respectively. Prior to the study, each of the players was given detailed information about the risks and injuries they could encounter during the study, and parental consent was obtained by their signatures on informed voluntary consent forms since the subjects were under the age of 18. Permission to conduct the study was obtained from Ankara University Medical Faculty’s Surgical and Medical Research Ethics Committee. Results. The results indicated a strong relationship between sprinting performance and horizontal jump performance (r=-.671 ̶ -.764; p=0.001) and also a large relationship between sprinting performance and upper extremity strength (r=-.633 ̶ -.703; p=0.001). The sprint performance (n=147) also significantly correlated with body weight (r=-.345 ̶ -.373; p=0.001) and height (r=-.445 ̶ -.505; p=0.001). Conclusions. The study results suggest that upper extremity strength is as important as the lower extremity strength for sprinting performance and that trainers should emphasize lower and upper extremity strength in training intended to improve sprinting performance.

In this study, we aimed to compare ACTN3 rs1815739, PPARA rs4253778 and IL-6 rs1800795 polymorphisms with aerobic endurance in volleyball players. Twenty-two volleyball players (age: 21.59 ± 2.70 years; height: 1.87 ± 7.92 m; body weight: 80.99 ± 8.14 kg; body fat: 12.05 ± 5.78%) participated in the study voluntarily. DNA extraction from buccal epithelial cells was provided by a commercial kit. Real-Time PCR was performed for genotyping. Statistical analysis of the test results was performed using SPSS 23 (SPSS Inc., Chicago, IL, USA) package program. Homogeneity of variance was analyzed by Levenne test and normal distribution was analyzed by Shapiro-Wilk test. One Way ANOVA Test was used to analyze all parameters. Significance was determined at p0.05). In the findings, no statistically significant difference was detected between the relevant polymorphisms and aerobic performance parameters in our cohort. In conclusion, ACTN3 rs1815739, PPARA rs4253778 and IL6 rs1800795 genes did not create any difference in aerobic endurance in volleyball players. Our results need to be confirmed by further studies.

Tr en Amaç: Bu çalışmanın amacı, 9-13 yaş aralığında olan tenis oynayan öğrencilerin bazı fizyolojik ve biyomotor özelliklerini belirlenmesi ve cinsiyetin performans üzerindeki etkisinin saptanmasıdır. Materyal ve Yöntem: Araştırmaya Ankara’da faaliyet gösteren bir tenis kulübünün yaşları 11,21±1,08 yıl, boy uzunlukları 1,52±0,11 m, vücut ağırlıkları 44,76±7,87 kg, antrenman yaşı 3,15±1,11 yıl olan 19 erkek ve yaş 1,05±1,51 yıl, boy uzunlukları 1,48±0,08 m, vücut ağırlıkları 35,84±5,75 kg, antrenman yaş ı 2,7±0,91 yıl olan 17 kız tenis oyuncusu katılmıştır. Sporculara ilk olarak antropometrik ölçümler uygulanmış, daha sonra 5, 10 metre sprint testi, esneklik testi, şınav testi, mekik testi, uzun atlama testi, sağlık topu fırlatma testi ve denge testi uygulanmıştır. Gönüllülerin tanımlayıcı istatistikleri hesaplandıktan sonra performans testlerindeki alınan verilerin Levene testi ile değerlendirilmiş ve normal dağılım gösterdiği görülmüştür. Gruplar arası farkı belirlemek için t-testi kullanılmıştır. Bulgular: Uygulanan testlerde 10 metre sprint testinin dışında cinsiyetler arasında istatistiksel olarak anlamlı bir fark görülmemektedir (p<0,05). Sonuçlar: Sonuç olarak; tenis oynayan 9-13 yaş aralığındaki sporcuların değerlendirmeye alınan parametreleri arasında cinsiyetler arası farkın olmadığı söylenebilir ve bu yaş grubu sporcularda cinsiyet ayrımı gözetilmeden benzer antrenman modellerinin uygulanabileceği düşünülmektedir. Aim: The aim of this study is to determine some physiological and biomotor properties of 9-13 years old tennis players, and detect the effect of gender on performance. Material and Methods: 19 voluntary male tennis players, (average age: 11.21±1.08 year, average height: 1.52±0.11 cm, average weight: 44.76±7.87 kg, average sport background: 3.15±1.11 year ),17 voluntary female tennis players, (average age: 11.05±1.51 year, average height: 1.48±0.08 cm, average weight: 35.84±5.75 kg, sport background: 2.7±0.91 year ) who exercise at a tennis club in Ankara participated in this study. The subjects’ anthropometric measurements were taken. Then, 5 m sprint test, 10 m sprint test, flexibility test, push up test, sit up test, long jump test, medicine ball throw test, stability test were performed on the mentioned subjects. After calculating the descriptive statistics of the voluntaries, the data collected from performance tests were evaluated with Levene test and it showed normal distribution. T test was used to identify which groups had significant differences. Results: In the applied test, it has been observed that except the 10-m sprint test; there were not any significant (p<0.05) differences. Conclusion: we could state that there is no difference between gender and all parameters of 9-13 years old tennis players and the similar training models can be applied to the players regardless of their gender.

Longitudinal studies evaluating the seasonal change of aerobic capacity in young soccer players of different age categories are limited. The aim of this study was to investigate the seasonal changes in the aerobic level of the youth academy players of a professional soccer team. This research study was carried out with a total of 51 soccer players in the U14, U15, U16, U17, and U18 categories of an elite soccer team. Aerobic capacities of the athletes were measured by Yo-YoIRT 1 Test. In the analyses, the normal distribution evaluations of the data were made with the Shapiro-Wilk test and the variance homogeneities were tested with the Levene’s Test. One Way ANOVA test was used to analyze all the parametric data. All statistical evaluations were performed with the help of the SPSS 21 package program. According to the Yo-YoIRT 1 test, increases or decreases were determined in the pre-season, mid-season and end-of-season evaluations. As a result, in the present study conducted to examine the seasonal changes of the young elite soccer players in the U14, U15, U16, U17, and U18 categories, Yo-YoIRT 1 values ​​in all categories increased significantly at the end of the season when compared to the pre-season and the mid-season. U14 and U16 age groups gained increasing acceleration starting from the pre-season. However, in the U15, U17, U18 age groups, the case is that acceleration decreases in the middle of the season and increases at the end of the season. It is thought that differences can be observed in the responses to the training loads during maturation. It can be suggested that the increase at the end of the season compared to the pre-season in all groups may be due to the fact that the adaptation of the athletes to the training programs are affected by the developmental characteristics regarding the age categories over time.

El objetivo de este estudio fue evaluar posibles diferencias entre victorias (9 partidos) y derrotas (9 partidos) de un equipo de fútbol profesional en una temporada de la Primera Liga Turca del Spor Toto. Durante 18 partidos de las competencias, se analizaron 7 parámetros. Los datos se examinaron en términos de aceleraciones totales (en número), desaceleraciones totales (en número), distancia (m), impacto (en número), distancia de sprint (m) y promedio de velocidad máxima (km / h). Los datos fueron recopilados utilizando el dispositivo de rastreo GPS Playertek durante los encuentros. La prueba de normalidad de los datos se realizó mediante la prueba de Shapiro-Wilk y la homogeneidad de la variación se evaluó mediante la prueba de homogeneidad de varianza de Levene. Como los datos mostraron una distribución normal en el análisis estadístico, se aplicó la prueba T de muestras pareadas. La significancia estadística (p 0.05) en términos de aceleraciones totales (en número), desaceleraciones totales (en número), impacto (en número), distancia de sprint (m) y promedio de velocidad máxima ( km / h) entre las derrotas y las victorias de un equipo de fútbol profesional, en cuanto al parámetro de distancia (m) se encontró diferencia significativa (p <0.05). Teniendo en cuenta esta información, se puede afirmar que la distancia puede ser determinante en los resultados de un partido de fútbol.