# Body Composition and Physical Performance by Playing Position in Amateur Female Soccer Players
## 4 Discussion
In 10 m, 20 m, and 30 m sprints, no significant differences by playing position were reported in the present study. These results are similar to those [PERSON] et al. [34] reported in division collegiate female soccer players, where no significant differences were reported in the 10 m sprint and 30 m sprint according to playing position. Likewise, [PERSON] et al. [10], in a study of elite youth male soccer players, reported no significant differences in 10 m, 20 m, and 30 m sprints according to playing position. However, in a study conducted by [PERSON] et al. [41] on semi-professional male soccer players, it was observed that defenders performed worse in 20 m and 30 m sprints compared to forwards, with these differences being significant (\(p\leq 0.002\)). Sprinting is one of the main actions in soccer, although it only constitutes between 1% and 12% of the total average distance traveled by a player during a match, that is, only 0.5% to 3% of the time of play in a match [42]. During a competitive match, players perform long sprints of 2 s to 4 s every 90 s to 180 s on average [42]. Regarding the player's playing position, training experience, and various tracking methods in individual intensity phases, the average sprint distance covered during a match is between 200 m and 1200 m [42; 43]. In modern soccer, a highly developed acceleration skill is required, given that the player's acceleration ability manifests itself at distancesof no more than 30 m [42]. Although our findings do not report differences in the 10 m, 20 m, and 30 m sprints depending on the playing position, it is crucial to consider that the number of sprint actions has been shown to vary according to each position on the field. For example, according to [PERSON] et al. [42], in the sprints from 0 to 10 m, the greatest number of sprints are performed by the outside defenders and the outside midfielders (difference of 0.9 \(\pm\) 1.0 m). In the sprints from 10.1 m to 20.0 m, the central defenders and the central midfielders perform fewer sprints, with differences in total distance of 3.9 \(\pm\) 2.5 m and 4.5 \(\pm\) 2.6 m, respectively, than outside midfielders, with a difference of 7.1 \(\pm\) 2.4 m, and forwards, with a difference of 7.8 \(\pm\) 2.9 m (\(p\) < 0.05). In sprints over 20 m, the majority are performed by forwards, with a difference in distance of 7.4 \(\pm\) 3.7 m, and outside midfielders, with a difference of 6.9 \(\pm\) 3.2 m, vs. defenders, with a difference of 4.1 \(\pm\) 1.9 m (\(p\) < 0.05). With all of the above, it is recommended that the training of forwards and outside midfielders should include running sprint speed components to a much greater extent than the loads for defenders and midfielders. Furthermore, running distances in training, in particular between 10.1 m and 20.0 m and over 20 m, should be adapted based on the playing positions of the soccer players [42]. Another result found in the present study was that goalkeepers showed a significantly lower ball-kicking speed in the dominant foot compared to defenders, midfielders, and forwards, while for the non-dominant foot, there was presented a significantly higher ball-kicking speed only in midfielders compared to goalkeepers. These results are similar to those reported by [PERSON] et al. [41], where it was found that defenders had a lower ball-kicking speed compared to midfielders and forwards, with these differences being significant (\(p\) < 0.05) in semi-professional youth male soccer players. However, in the study by [PERSON] et al. [18], no significant differences were reported in the ball-kicking speed according to the playing position of elite female soccer players. To increase the probability of scoring a goal, players must achieve the highest possible ball-kicking speed, which depends on variables such as foot speed at the moment of impact and the quality of the ball serve-foot impact [44; 45]. Furthermore, if the shot presents a faster velocity, it is less likely that the goalkeeper or opposing player will have enough time to react [46; 47].