## 3 Results  
For height, trimester have significant effect (\(p\) < 0.01; df = 1.37; F = 5.85), and the post-hoc test did not show any significative differences. The interaction between trimester and category of age do not have significant effect (\(p\) = 0.39; df = 6.87; F = 1.06). Also, there are differences in height between the different categories of age (\(p\) = 0.02; df = 5; F = 5.15). The post-hoc test showed statistical differences between the category U14 and the rest of categories of age (\(p\) < 0.05) (Table 4). For weight, trimester have significant effect (\(p\) < 0.001; df = 1.54; F = 144.25), and there was an interaction between the trimester and the category of age (\(p\) = 0.05; df = 7.68; F = 1.98) and differences between the categories of age (\(p\) < 0.001; df = 5; F = 8.14). The older age groups showed the highest weight values (Table 4). In the case of fat percentage there were differences between trimesters (\(p\) < 0.001; df = 1.80; F = 37.26). In this case there was a significant trimester-age category interaction (\(p\) < 0.02; df = 2.09; F = 8.99) and no differences between age categories (\(p\) = 0.13; df = 5; F = 2.30). Post-hoc analyses showed significant differences between the first and second trimester (being higher in the second trimester; \(p\) = 0.04) and between the U14 category, with U16, U17 and U18 (\(p\) < 0.001) (Table 4). Finally, in the case of muscle mass there were significant differences between trimesters (\(p\) < 0.001; df = 1.57; F = 150.66); a significant trimester-age category interaction (\(p\) < 0.001; df = 7.87; F = 3.56) and significant differences between the different age categories. Post-hoc analyses showed differences between trimester 1 and trimester 3 (\(p\) < 0.05) and between almost all age categories (\(p\) < 0.05) (Table 4). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Age Category** & **Variable** & **Trimester 1** & **Trimester 2** & **Trimester 3** \\ \hline U14 & Height (cm) & 167.9 + 1.5 & 168.5 + 1.5 & 169.4 + 1.5 \\  & Weight (kg) & 62.3 + 1.6 & 64.4 + 1.6 & 64.7 + 1.6 \\  & BF (\%) & 14.8 + 0.6 & 15.7 + 0.6 & 14.8 + 0.6 \\  & Muscle mass (\%) & 51.7 + 1.2 & 52.9 + 1.2 & 53.7 + 1.2 \\ \hline U15 & Height (cm) & 172.6 + 1 & 173.1 + 1 & 173.9 + 1 \\  & Weight (kg) & 61.6 + 1.2 & 63 + 1.2 & 63.9 + 1.2 \\  & BF (\%) & 13.5 + 0.5 & 14.3 + 0.5 & 14.1 + 0.5 \\  & Muscle mass (\%) & 53.1 + 0.8 & 53.8 + 0.8 & 54.8 + 0.8 \\ \hline U16 & Height (cm) & 170.9 + 1 & 171.7 + 1 & 172.6 + 1 \\  & Weight (kg) & 60 + 1.1 & 61.4 + 1.1 & 62.5 + 1.1 \\  & BF (\%) & 12.8 + 0.4 & 13.4 + 0.4 & 13 + 0.4 \\  & Muscle mass (\%) & 52 + 0.8 & 53.1 + 0.8 & 54.3 + 0.8 \\ \hline U17 & Height (cm) & 173.4 + 0.8 & 173.8 + 0.8 & 173.3 + 0.8 \\  & Weight (kg) & 64.5 + 0.9 & 65.8 + 0.9 & 66.4 + 0.9 \\  & BF (\%) & 12.9 + 0.3 & 13.5 + 0.3 & 13.3 + 0.3 \\  & Muscle mass (\%) & 56 + 0.7 & 56.7 + 0.7 & 57.4 + 0.7 \\ \hline U18 & Height (cm) & 175.1 + 0.7 & 175.4 + 0.7 & 175.8 + 0.7 \\  & Weight (kg) & 66.3 + 0.8 & 67.6 + 0.8 & 68.2 + 0.8 \\  & BF (\%) & 12.7 + 0.3 & 13.3 + 0.3 & 13.4 + 0.3 \\  & Muscle mass (\%) & 57.7 + 0.6 & 58.5 + 0.6 & 58.9 + 0.6 \\ \hline U19 & Height (cm) & 173.3 + 1.4 & 175.4 + 1.4 & 174 + 1.4 \\  & Weight (kg) & 70.8 + 1.5 & 71.2 + 1.5 & 71.8 + 1.5 \\  & BF (\%) & 13.7 + 0.5 & 14 + 0.5 & 14.1 + 0.5 \\  & Muscle mass (\%) & 60 + 1.1 & 60 + 1.1 & 60.7 + 1.1 \\ \hline \hline \end{tabular} BF: Body Fat Percentage.  
\end{table} 
Table 4: Raw anthropometric variables depending on category of age (Mean \(\pm\) Standard Error). Considering the TCs, trimester showed significant effects in relation to height-TC (Table 5). In relation to age category or the interaction trimester by age category there were no significant differences in any of the cases (Table 5).