Thesis title: evaluation of the effects of core trainings on quickness and agility in tennis players

Purpose: In this study conducted, it was aimed to examine the effects of eight-week core training applied to young tennis players on strength, agility and sprint performance. Method: 18 tennis players in the 14-16 age group who participated in the tennis competitions held in Izmir in the 2020-2021 season participated in this study. Tennis players were divided into two groups as experimental and control groups, and the tennis players in the experimental group participated in eight-week core training. During this process, the tennis players in the control group went on the tennis-specific technical training program. At the beginning and end of the study, 10-30 m sprint test, push-up test, leg lift test, plank test and 505 agility test were applied to the athletes. Independent Samples T test and Paired T test in the SPSS 22.0 program were used in the analysis of the data obtained. Results: According to the findings obtained in the study, it was found that when compared to the tennis players in the control group, the tennis players in the core training group had a higher level of improvement in strength, agility and sprint performance. Conclusion: As a result, it can be said that core training is more effective than technical training program in increasing strength, agility and sprint performance in young tennis players. Keywords: Tennis, core training, strength, agility, sprint performance