## 4 Discussion  
The objectives of the present work were: (a) to analyse the changes in Mn and Mo concentrations in plasma, urine, erythrocytes, and platelets during a sports season in soccer players and (b) to analyse the differences between sexes. To our knowledge, this is one of the first studies to analyse Mn and Mo concentrations during a season in different biological matrices. Information regarding these minerals in athletes is scarce, which highlights the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Men’s Soccer** & **Women’s Soccer** & **Sex Effect** & **Time Effect** & **Sex \(\times\) Time** \\ \hline \multirow{3}{*}{\begin{tabular}{c} Mo Plasma \\ (\(\mu\)g/L) \\ \end{tabular} } & 1 st assessment & 2.07 \(\pm\) 0.59 & 1.44 \(\pm\) 0.71 & & & \\ \cline{2-6}  & 2 nd assessment & 2.67 \(\pm\) 0.75 ** & 1.93 \(\pm\) 0.45 ** & \textless{}0.001 \# & \textless{}0.001 \# & 0.216 \\ \cline{2-6}  & 3 rd assessment & 2.59 \(\pm\) 0.79 ++ & 2.39 \(\pm\) 0.49 ++ & & & \\ \hline \multirow{3}{*}{\begin{tabular}{c} Mo Urine \\ (\(\mu\)g/L) \\ \end{tabular} } & 1 st assessment & 53.98 \(\pm\) 40.77 & 57.55 \(\pm\) 46.16 & & & \\ \cline{2-6}  & 2 nd assessment & 67.16 \(\pm\) 37.14 \(\sim\) & 34.33 \(\pm\) 24.88 \(\sim\) & 0.066 \# & \textless{}0.001 \# & 0.057 \$ \\ \cline{2-6}  & 3 rd assessment & 24.71 \(\pm\) 16.63 ++ & 19.23 \(\pm\) 13.80 ++ & & & \\ \hline \multirow{3}{*}{\begin{tabular}{c} Mo Erythrocyte \\ absolute \\ (\(\mu\)g/L) \\ \end{tabular} } & 1 st assessment & 19.87 \(\pm\) 6.15 & 30.97 \(\pm\) 33.61 & & & \\ \cline{2-6}  & 2 nd assessment & 42.45 \(\pm\) 37.61 ** & 44.37 \(\pm\) 48.36 ** & 0.730 & 0.003 \# & 0.088 \$ \\ \cline{2-6}  & 3 rd assessment & 26.73 \(\pm\) 20.11 ++ & 22.85 \(\pm\) 9.15 ++ & & & \\ \hline \multirow{3}{*}{\begin{tabular}{c} Mo Erythrocyte \\ relative \\ (pg/cell-6) \\ \end{tabular} } & 1 st assessment & 2.66 \(\pm\) 1.01 & 3.50 \(\pm\) 5.38 & & & \\ \cline{2-6}  & 2 nd assessment & 8.77 \(\pm\) 7.99 ** & 10.26 \(\pm\) 10.59 ** & 0.574 & 0.002 \# & 0.121 \\ \cline{2-6}  & 3 rd assessment & 5.60 \(\pm\) 3.98 ** & 4.58 \(\pm\) 1.68 ** & & & \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} Mo platelets \\ absolute \\ (\(\mu\)g/L) \\ \end{tabular} } & 1 st assessment & 7.51 \(\pm\) 2.51 & 8.71 \(\pm\) 4.18 & & & \\ \cline{2-6}  & 2 nd assessment & 6.94 \(\pm\) 2.98 ** & 8.15 \(\pm\) 5.32 ** & 0.346 & 0.041 \# & 0.217 \\ \cline{2-6}  & 3 rd assessment & 3.88 \(\pm\) 1.53 ++ & 4.51 \(\pm\) 1.42 ++ & & & \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Mo platelets \\ relative \\ (pg/cell-3) \\ \end{tabular} } & 1 st assessment & 0.040 \(\pm\) 0.014 & 0.042 \(\pm\) 0.017 & & & \\ \cline{2-6}  & 2 nd assessment & 0.032 \(\pm\) 0.015 ** & 0.037 \(\pm\) 0.027 ** & 0.991 & \textless{}0.001 \# & 0.996 \\ \cline{2-6}  & 3 rd assessment & 0.024 \(\pm\) 0.021 ++ & 0.028 \(\pm\) 0.005 ++ & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Mo concentrations in the compartments evaluated throughout the study in the two study groups. novelty of the present study. For a better understanding of this section, the results obtained on Mn and Mo concentrations will be discussed separately. Mn and Mo absorption could be influenced by Fe concentrations. Gastrointestinal Mn absorption involves the main intestinal Fe transporters such as DMT1. The activity of this transporter increases when Fe stores are low, which would explain the increased Mn absorption under Fe deficiency conditions [33]. On the other hand, the functioning of most of the molybdenum depends on Fe metabolism to provide Fe sulphide groups and heme groups. The main interrelationship is the role that XO could play in the release of Fe from ferritin [34]. Mn reference intakes established by sex (mg/day) usually vary between 3.4 mg/day for men and 2.7 mg/day for women [35]. Mn concentrations in athletes have been previously analysed in serum, urine [18; 19], and erythrocytes [36]. However, the literature regarding platelets is scarce. Mn concentrations in this research were within the range reported in other studies [37; 38].