## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**r**} \\ \cline{2-5}  & **U10** & **U11** & **U12** & **Total** \\ \hline \multirow{3}{*}{**Body Height**} & [PERSON] (\(-\)0.821) & [PERSON] (\(-\)0.728) & & \\  & [PERSON] (\(-\)0.572) & Yo-Yo IR1 (\(-\)0.552) & 15 m sprint (0.733) & - \\  & & [PERSON] (\(-\)0.522) & & \\  & [PERSON] (\(-\)0.663) & [PERSON] (\(-\)0.582) & & \\
**Body Weight** & [PERSON] (\(-\)0.599) & [PERSON] (\(-\)0.577) & - & - \\  & & Yo-Yo IR1 (\(-\)0.518) & & \\
**BMI** & [PERSON] (\(-\)0.531) & [PERSON] (\(-\)0.505) & - & - \\  & & [PERSON] (\(-\)0.919) & 10 m sprint (\(-\)0.815) & \\  & 15 m sprint (\(-\)0.790) & 15 m sprint (\(-\)0.849) & [PERSON] (\(-\)0.805) & 10 m sprint (\(-\)0.797) \\
**Body Fat** & 10 m sprint (\(-\)0.746) & Yo-Yo IR1 (\(-\)0.720) & [PERSON] (\(-\)0.730) & 15 m sprint (\(-\)0.744) \\  & Yo-Yo IR1 (\(-\)0.506) & Medicine ball & 15 m sprint & [PERSON] (\(-\)0.513) \\  & & throw (\(-\)0.584) & (\(-\)0.565) & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Correlation coefficients between anthropometric and physical fitness parameters in relation to age groups. Only relevant correlation coefficients (r \(\geq\) 0.5) are reported. determine the consequences of excessive weight in young handball players and to develop exercise interventions targeting weight management. Increasing competitive levels in older handball athletes typically comes with a reduction in body fat and body mass. However, a concern of coaches is to ensure that any decreases in body mass and body fat occur without a concomitant decrease in lean mass. Sprint performance did not significantly differ between age groups. However, sprint velocity for short distances and the ability to accelerate and decelerate with and without change of directions are fundamental in team handball. In many game situations, such as during a fast break or while returning to defense after a lost ball, players sprint for about 10-30 m [13]. Players are required to cover distances with maximal speed from the phase of attack to the phase of defense after a lost ball or to prevent a fast break. The average difference between age groups ranged from 6% (U10 to U11; 15 m sprint) to 18% (U11 to U12; 10 m sprint). The 15 m sprint times in the present study were 3.82, 3.43, and 3.63 s for the U12, U11, and U10, respectively. [PERSON] et al. [11] described that in young male handball players aged 14.3 years, backs and wings displayed the best 30 m sprint performances. However, all players in the current study showed similar sprint times to those of similar ages on the Greek national team [11]. Researchers who have compared elite to sub-elite players or elite to amateur handball players have reported differences in sprinting ability [30]. In our study, jump performance was similar between age groups. The average difference between age groups ranged from 1% (U10 to U11; CMJ) to 10% (U10 to U11; SJ). Our results support previous research that described mean values for sub-elite male and female players [30] since handball is a contact sport where jumping, hitting, blocking, and pushing are common, thus making strength a necessity to perform at the highest level in youth and adult team handball [1; 2; 3]. Significant differences regarding the parameters of body height, body mass, and throwing performance were only found in comparison with the U12 group of handball players. In previous research, elite players were reported to perform, on average, 8.2% better on the CMJ and 8.4% better on the five-jump test compared with the non-elite players over a three-year period [13]. In this age group, a small difference in maturation may imply a substantial difference in body height and weight (mass), associated with a considerable difference in performance [34]. This finding is supported by the fact that during pre-puberty, before the growth spurt, there are small within-group differences in anthropometrics [35].