Therefore, this study aims to verify the effects of a soccer training program based on the dynamic-ecological approach on U13 sub-elité players' physical efficiency by analysing explosive strength, speed, resistance to speed and muscle flexibility. This study hypothe-sises that the dynamic-ecological approach can consistently help players develop adequate physical efficiency and motor coordination.

Nowadays, research in youth soccer consists of methodological choices that can raise ac-tivity volumes and exercise intensity to promote proper training for youth soccer de-mands. Therefore, the present cluster randomised trial aims to evaluate the effects on physical performance parameters of the dynamic-ecological approach compared with a traditional one in a group of sub-élite U13 players. Thirty-five male children (age 12.16 ± 0.55 years; weight 45.59 ± 7.15 kg; height 145.5 ± 4.2 cm; BMI 15.8 ± 2.1 kg*m-²) were re-cruited for this trial from two teams belonging to sub-élite soccer schools and randomly assigned in a dynamic-ecological approach (DEA) or a traditional training (TTG) group. The training program lasted six weeks and consisted of 18 training sessions of 90 minutes each (3 sessions per week). The sample was evaluated by Standing Long Jump (SLJ), hop test (HT), 10 m sprint (10m), 10 x 5 m shuttle run test (SRT) and Leg Raise test (LR). The DEA group showed significantly higher results in the SLJ (p< .001), HT left leg (p<.001), 10m sprint (p<.001), and SRT (p<.001). In conclusion, the dynamic-ecological approach provides higher performance adaptations. Therefore, this approach can be considered a suitable method to optimise prepubertal player training, mainly when no fitness or strength coach is available.

Inclusion Criteria:

• had not suffered an injury in the previous 6 months;
• who, in the 4 weeks before the study, had systematically performed the training sessions without interruptions or absences;
• all those who, upon medical evaluation, fell within stages 3 and 4 of Tanner's classification

Exclusion Criteria:

-Goalkeepers and players who had been injured in the previous six months or did not meet the established minimum compliance were excluded from this study

Thirty-five male children under 13 years old

Italian GDPR law