Effectiveness of a Standard Training Protocol on Conditional Capacities in U14 Footballers

Modern football has undergone significant changes in its performance model. In the past, results depended mainly on athletes with technical skills, but with the introduction of new tactical strategies, coaches have demanded higher athletic performance, making physical fitness a determining factor. In football academies, it is therefore essential to develop strength, speed and endurance during puberty, integrated with technical and tactical work, to prepare young players for the transition to higher categories. Although the literature highlights the effectiveness of protocols geared towards individual conditional capacities, there are still few studies that have analysed protocols capable of simultaneously developing multiple components of physical performance in young footballers. The objective is to analyse and quantify adaptations in conditional capacities and their mutual relationships after a standard, structured training protocol aimed at improving conditional capacities in Under-14 footballers at a football academy. Fifteen Under-14 footballers took part in three 90-minute sessions per week for six months, including linear sprints, changes of direction, plyometric exercises, intermittent aerobic work and technical-tactical activities. Conditional capacities were assessed using 30 m sprints, 5–10–5 sprints, long jump, quintuple jump and Sit & Reach tests, administered before and after the intervention. Statistical analysis included paired t-tests, Pearson correlations and multivariate linear regression (p < .05). All capacities improved significantly: sprint, agility, long jump and quintuple jump (p < .000001) and flexibility (p = .0028). A moderate correlation emerged between linear speed and agility (r = 0.59), while the others were weak. Regression shows that no initial ability predicts the post-sprint; the pre 5–10–5 predicts post agility (B = 1.046; p = .001) and the pre long jump predicts both the post long jump (B = 0.823; p = .026) and the post Sit & Reach (B = 18.131; p = .009). The multimodal protocol proved effective in improving various conditional capacities in young Under-14 footballers. The only significant relationship is between linear speed and agility; the other capacities appear to be independent, supporting a multifactorial development model in puberty. The study highlights the importance of integrated programming consistent with biological maturation in football academies.