The importance of nutrition is known in swimming as in other sports branches. Knowing the right strategies for nutrition will enable swimmers to improve their recovery time as well as increase their performance. This study aims to investigate the effects of with and without diet training programs on the performance and recovery times of male swimmers aged 9-14. 24 performance swimmers in the 9-14 age group participated in the study. 50m-400m freestyle swimming performances and recovery times of the participants were tested in 2 different conditions (with and without diet). While performing without diet, the participants continued their normal eating habits. Before taking dietary performance, each participant was given a suitable diet program (60% carbohydrate, 15% protein, 25% fat) depending on the individual differences of the participants. After the diet program was applied for 2 days, the dietary performances of the participants were taken. According to the findings we obtained from this study on 24 performance swimmers between the ages of 9-14, it was observed that the nutrition program applied improved the 50m and 400m swimming performance and recovery time of the athletes. Considering the effects of nutrition on performance and recovery time, special diet programs should be prepared for each athlete to increase their performance of the athletes. Considering the individual differences of the athletes, with the help of an expert, the preparation of the diet program according to the needs of the athletes is necessary for optimal performance.