## 4 Discussion  
The study of body composition is particularly important in sports in which body weight must repeatedly move against gravity. The body composition of football players is likely to change over the course of the competitive season as a result of training and competition, diet and habitual activity. Multiple factors affect the relationship between measured % fat and BMI. Polynomial regression analysis showed that the relationship between % fat and BMI was quadratic, not linear. This curvilinear trend was similar for both female and male data [18]. Although the aim of this study was not to analyze body composition by position, these data were also grouped by relevance to on-field football sport performance research, showing statistically significant differences according to playing position as expected (\(p<0.001\)). With respect to Colombian professional players who play in Europe, the mean value obtained for weight was 76.04 kg, and the mean values for height were 1.79 m and 10.53% and 7.15% for % fat according to [PERSON] and [PERSON], respectively, which are very similar to the data obtained in the study by [PERSON] in which a comparative study of different formulas for estimating the percentage of fat with absorptiometry in Colombian football players was proposed [19]. Similar values were obtained in the Chilean subjects studied with respect to those obtained by other authors [20; 21; 22]. The mean weight value was 74.18 kg, and the mean height values were 1.75 m and 11.84% and 8.36% for % fat according to [PERSON] and [PERSON], respectively. The Argentinian players studied had the lowest values for weight and height, but they did not have the lowest values for fat. In this case, we found different values to those obtained by [PERSON] et al. [23] or those found by [PERSON] et al. [24], but these studies were carried out on amateur players. [PERSON] et al. [25] found a homogeneous distribution in the Venezuelan football players they studied, with similar data to those found in the Venezuelan football players in this study. The same occurred with the study by [PERSON] et al. [26], where it was shown that Brazilian footballers have specific morphological characteristics that are different from those of other footballers. It should be noted that no studies have been found that show body composition values of Uruguayan, Paraguayan or Ecuadorian football players, demonstrating the importance of carrying out descriptive studies in football players of different nationalities. In the correlation study of weight, BMI and height with bodyfolds and % fat, it is observed that Colombian and Venezuelan football players have a negative correlation of weight with % fat, while this is positive for Argentinians, Chileans and Uruguayans. Colombians and Venezuelans seem to have lower fat values when their weights are higher, in contrast to Argentinians, Chileans and Uruguayans, where the decrease in body fat could be associated with a decrease in weight [27]. Regarding height, only Colombians and Venezuelans have an inverse correlation with % fat. [PERSON] and [PERSON] [28] reviewed research comparing white and black racial groups and found that black males had higher body protein content and mineral mass than white males, resulting in higher bone and muscle density and muscle mass, with a tendency towards a mesomorphic somatotype. However, these studies have not been conducted in other populations that may have different body composition characteristics (Caucasians, Native American, Asian, African American, and Polynesian people) where there seem to be differential changes in % fat and BMI [17]. The present study results suggest that endogenous differences in the fat-free compartment between ethnic groups are reduced as long-term effects of elite football participation. However, longitudinal studies would be needed to confirm this.