## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multirow{2}{*}{\(\mathbf{R^{2}}\)} & \multirow{2}{*}{\(\mathbf{p}\)**-Value**} & **Included Independent** & \multirow{2}{*}{**SC**} & \multirow{2}{*}{\(\mathbf{p}\)**-Value**} & \multirow{2}{*}{**Predictive Equation**} \\  & & & **Variables** & & & \\ \hline \multirow{3}{*}{Sit and reach} & \multirow{3}{*}{0.24} & \multirow{3}{*}{\(<\)0.001} & Biacromial breadth & 0.27 & 0.001 & Sit and reach = \(-\)199.309 + 1.183 \(\times\) \\  & & & \begin{tabular}{c} Cormic index \\ Relative arm span \\ \end{tabular} & 0.28 & \(<\)0.001 & biacromial breadth + 1.630 \(\times\) \\  & & & \begin{tabular}{c} Relative arm span \\ \end{tabular} & 0.24 & 0.002 & 77.628 \(\times\) relative arm span \\ \hline \multirow{3}{*}{Back scratch} & \multirow{3}{*}{0.21} & \multirow{3}{*}{\(<\)0.001} & Relative arm span & 0.40 & \(<\)0.001 & Back scratch = \(-\)77.836 + 85.116 \(\times\) relative \\  & & & \begin{tabular}{c} \(\sum\)8 Skinfolds \\ \end{tabular} & \(-\)0.19 & 0.010 & arm span \(-\) 0.031 \(\times\) \\ \hline \multirow{3}{*}{Horizontal jump} & \multirow{3}{*}{0.13} & \multirow{3}{*}{\(<\)0.001} & Age & 0.20 & 0.010 & Horizontal jump = 1.348 \(\pm\) 0.0033 \(\times\) age \(-\) \\  & & & \begin{tabular}{c} \(\sum\)8 Skinfolds \\ \end{tabular} & \(-\)0.27 & 0.001 & 0.002 \(\times\) \\ \hline \multirow{3}{*}{Medicine ball throw} & \multirow{3}{*}{0.37} & \multirow{3}{*}{\(<\)0.001} & Biacromial breadth & 0.43 & \(<\)0.001 & Medicine ball throw = \(-\)6.818 + 0.232 \(\times\) \\  & & & \begin{tabular}{c} Age \\ Corrected arm girth \\ \end{tabular} & 0.18 & 0.011 & biacromial breadth + 0.149 \(\times\) age + 0.076 \(\times\) \\  & & & \begin{tabular}{c} Corrected arm girth \\ \end{tabular} & 0.15 & 0.045 & corrected arm girth \\ \hline \multirow{3}{*}{CMJ} & \multirow{3}{*}{0.21} & \multirow{3}{*}{\(<\)0.001} & \(\sum\)8 Skinfolds & \(-\)0.38 & \(<\)0.001 & CMJ = 18.339 \(-\) 0.050 \(\times\) \\  & & & Age & 0.24 & 0.002 & \(\times\) age \\ \hline \multirow{3}{*}{CMJ power} & \multirow{3}{*}{0.79} & \multirow{3}{*}{\(<\)0.001} & Body mass & 0.58 & \(<\)0.001 & CMJ power = 33.780 + 6.391 \(\times\) body mass + \\  & & & \begin{tabular}{c} Biacromial breadth \\ Muscle mass \\ \end{tabular} & 0.24 & \(<\)0.001 & 13.701 \(\times\) biacromial breadth + 18.304 \(\times\) \\  & & & \
\begin{tabular}{c} Corrected thigh girth \\ \end{tabular} & \(-\)0.30 & 0.010 & muscle mass \(-\) 7.662 \(\times\) corrected thigh girth \\  & & &
\begin{tabular}{c} Biilocorestal breadth \\ \end{tabular} & \(-\) 0.18 & 0.002 & \(-\) 10.436 \(\times\) bilelecorestal breadth \\ \hline \multirow{3}{*}{Sprint} & \multirow{3}{*}{0.37} & \multirow{3}{*}{\(<\)0.001} & \(\sum\)8 Skinfolds & 0.37 & \(<\)0.001 & Sprint = 3.809 \(\pm\) 0.003 \(\times\) \\ \hline \multirow{3}{*}{Agility test} & \multirow{3}{*}{0.04} & \multirow{3}{*}{0.019} & Fat mass & 0.20 & 0.019 & Agility test = 8.718 + 0.038 \(\times\) fat mass \\ \hline \multicolumn{6}{c}{SC: Standardized coefficient.} \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Regression models of the performance in different physical fitness tests. higher adiposity and an earlier onset of maturation being observed [43]. Furthermore, estrogens not only promote the peripheral accumulation of adipose tissue but also play a crucial role in bone formation [46], which could explain the differences found between groups in the bone diameters measured. Regarding the differences in variables related to muscle mass, during adolescence, the increase in muscle mass is associated with increases in the concentrations of growth hormone (GH), insulin-like growth factor 1 (IGF-1) and testosterone [46; 47]. These hormones increase in concentration by between 1.5 and 3 times around the APHV with respect to previous basal levels and are therefore determinant in the changes in muscle development during adolescence [46].