## 2 Materials and Methods  
Design and subjects: The study design was cross-sectional, descriptive, and comparative. The study protocols and procedures were developed following the standards of the Declaration of Helsinki and approved by the Research Ethics Committee of the University of Murcia, Spain (code: 17772). Prior to participating in the study, all participants were informed of the objectives of the research and provided their written informed consent. The sample was composed of 238 football players from European professional football leagues aged between 22 and 30 years old, with a minimum sport training experience of one year playing at a professional level in Europe. The inclusion criteria were males of Latin American nationality and professional players of a European football team in the first- or second-division leagues. Excluded were players who were injured at the time of the study or had an illness. The data were collected in the European cities where the study subjects played in the professional football leagues of Spain, Italy and England during the competition period. In addition, an informed consent form was offered to all the participants where they were informed about the objectives of the study, and their voluntary participation in it was approved.  
Anthropometrics: Anthropometric variables were taken by trained regular personnel of the European Leagues, certified by ISAK, International Society for the Advancement of Kinanthropometry, with a technical measurement error of 0.04% for basic measurements and of 2.12% for skinfolds, following the international standards recommended by the ISAK. All measures were taken in the morning. Height was measured (centimeters) using Seca 214 (SECA Deutschland, Hamburg, Germany) and weight (kilograms) was measured with Tanita BC-418 (Tanita, Tokyo, Japan). On the measurement days, the football players should neither have performed high-intensity exercise the previous day, nor have performed training or stretching sessions on the same day. All participants were weighed wearing light clothing and barefoot (0.6 kg was subtracted from the total for clothing) [1]. Body mass index (BMI) was calculated by dividing the weight in kilograms by the square of the height in meters (kg/m\({}^{2}\)). The skinfolds were measured with a Holtein plicometer. The folds measured were tricipital, subscapular, suprailiac, abdominal, mid-leg and calf. Both [PERSON]'s and [PERSON]'s fat estimation formulas were used [12; 13; 14; 15; 16; 17]. All anthropometric measurements were taken in triplicate, using the mean of both for subsequent analysis.  
Statistics: Sample size calculations were performed using the G* POWER software v. 3.1.9.7 (Heinrich-Heine-Universitat Dusseldorf, Dusseldorf, Germany) with an alpha of 0.05, an effect size of 0.40 and a statistical power of 0.95, and to establish statistical differences between conditions, a minimal of 144 participants were required to be included. Statistical analysis was performed with the R statistical computing software v.4.3.0 (R Core Team, Vienna, Austria). The normality of the variables was analyzed using the Kolmogorov-Smirnov test with the Lilliefors correction, and the homoscedasticity was analyzed using the Levene test. For the basic descriptions, means and standard deviations (SD) were used. For comparisons between groups of continuous variables, the parametric ANOVA test was used. For comparisons between groups of bivariate correlations, Pearson's correlation coefficient was used. All \(p\)-values given are based on the two-tailed test, and the level of significance for all tests was set at 95%.