# Anthropometric Characteristics and Somatotype of Young Slovenian Tennis Players
## 4 Discussion
However, our study has shown that somatotypes change in young athletes. This is particularly true for girls, where the ectomorphic somatotype predominates in the younger categories (U12 and U14), while from the age of 14, a clear change in the somatotype towards the endomorphic somatotype can be observed. The proportion of mesomorphic players among junior girls is around a third to a quarter. In our study, mesomorphic and ectomorphic somatotypes predominate in boys, with a tendency towards the meso-ectomorphic type with increasing age. The same results were obtained in the study by [PERSON] et al. [13], who described the mean somatotype in boys (U14 and U16) as meso-ectomorphic and in girls as meso-ectomorphic. In contrast, [PERSON] et al. [29] found in a relatively small sample of adult athletes that both tennis and paddle players have a dominant meso-endomorphic somatotype. This study was conducted on a sample of junior tennis players who, due to intensive biological development, training, and competition, undergo numerous changes that can also be observed in adult athletes. For example, when analysing successful male tennis players at Grand Slam tournaments, [PERSON] and [PERSON] [30] found that the body shape of elite tennis players changes over time, mainly in the direction of greater muscle mass rather than greater adiposity. Anthropometric characteristics can have a significant indirect influence on tennis performance, especially from a technical point of view. For example, a systematic review by [PERSON] et al. [31] found a positive correlation between serve speed and height, body mass, and BMI in young tennis players, which is even more pronounced in top adult players. From a practical perspective, the increasing prevalence of mesomorphic profiles in boys as they age indicates a natural progression towards more muscular and athletic body types, likely due to maturation and the physical demands of tennis. Coaches should sup port this development with progressive strength and endurance training while avoiding early overloading in younger players who are not yet biologically mature. In girls, the shift from ectomorphic to endomorphic profiles during and after puberty likely reflects hormonal changes that contribute to a natural increase in body fat, which is important for healthy development and reproductive function. While this is a normal physiological process, it can also be a sign of changes in exercise intensity, diet, or fitness. If not addressed, increasing endomorphy can affect exercise efficiency and performance. Therefore, programs for adolescent girls should emphasise strength training, aerobic conditioning, and individualised nutritional guidance and should be carefully monitored during and after puberty. One limitation of this study is that we did not include the observation of biological maturation, dietary habits, and training characteristics of the athletes in this study, as this would have significantly improved the quality of the analysis. Over the last two decades, the sport of tennis has certainly changed, specifically the demands of the game; the training methods; the social environment and conditions for playing the sport; the motivation of young athletes; and finally, the sporting competition have changed. This could also be influenced by possible imbalances in repeated measurements between age groups, over which we had no control. The anthropometric measurements were carried out under the same conditions and with the same equipment, and the person who trained the measurement subjects and the measurement supervisor remained the same. A long period of time can be a problem for the measurement subjects, but at the same time, the aim of this study was to precisely determine the temporal aspect of the changes in the anthropometric characteristics of young tennis players. This study provides a good and detailed insight into the changes in the physical characteristics of young tennis players, in particular the development of somatotype in athletes, especially girls.