###### Abstract
Different effects of adult training content on adolescent athletes should also be considered. It is known that in adolescent swimmers, along with swimming exercises, certain changes occur in the conduction system while maintaining systolic and diastolic functions and without changes in left ventricular size [12]. According to another experimental study, unlike adults, the heart rate value in adolescent swimmers has a limited effect on determining the balance between training load and the athlete's tolerance capacity [13]. During the adolescence period, adaptations in athletes become even more crucial when considering the hormonal changes induced by both existing hormonal fluctuations and exercise-induced hormonal changes [14]. Training load is a critical concept in swimming, and it represents the cumulative stress placed on a swimmer's body during training sessions over time [15]. To optimize performance, coaches carefully design training plans that balance the training load with periods of recovery [16]. According to a review, the highest training volume for adolescent swimmers was reported as 17.27 \(\pm\) 5.25 h/week, whereas for adults, it was 26.8 \(\pm\) 4.8 h/week. However, in most athletes, it was determined that training at these levels led to shoulder pain [17]. If training loads are not carefully determined in adolescent athletes, it can lead to early burnout, dropping out of school, and the onset of physiological and psychological illnesses [14]. On the other hand, combining swimming with weight-bearing and strength activities during childhood and adolescence promotes better bone development [18]. Adolescents undergo significant physical growth and development, which can impact their swimming performance. Factors such as changes in body composition, muscle development, and bone growth should be considered when assessing and training adolescent swimmers [19]. Applying appropriate training to adolescent swimmers during the adolescence period is crucial for positive effects on performance and overall health [19]. In improving aerobic endurance in adolescent swimmers, it has been reported that interval training with swimming distances at race pace for 200 m and 400 m, along with 30-45 s of rest intervals, can be effective [20]. A 15-week interval training program, whether with a low or high volume, has been found to increase stroke length, stroke rate, and stroke count in adolescent swimmers [21]. Considering the similar physiological effects of 100 m and 200 m interval training at the maximum aerobic speed in adolescent swimmers [22], it is worth considering that varying the volume of training could alter the resulting physiological effects. [PERSON] [23] suggests that aerobic interval training positively impacts the performance of early adolescent freestyle swimmers. In another study, [PERSON] et al. [24] suggest that sprint interval swimming exercise had a modest but potentially beneficial impact on irisin levels and redox status markers in adolescent swimmers. [PERSON] et al. [25] demonstrate that both pool-based sprint training and dry land (ergometer) training led to significant improvements in anaerobic sprint ability among adolescent swimmers. This suggests that using multiple training modalities (both in the pool and on dry land) can be effective in enhancing sprint performance in swimmers. Swimming, as a sport that spans various age categories such as children and adolescents, could be an ideal field for investigating the effects of high-intensity interval training [26]. Despite being a popular sport, the challenges in obtaining physiological measurements and the individual effects of water on athletes contribute to the presence of fewer studies in the literature compared to other sports like athletics and cycling [27]. Additionally, as far as we know, interval training at low, moderate, and high volumes has not been extensively studied in adolescent swimmers.