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Agility and change of direction in soccer: differences according to the player ages.

BACKGROUND
The goal of this study was to compare the changes of direction speed (CODS) and reactive agility (RA) in soccer players of different ages, in order to optimize the best training of these skills.


METHODS
One hundred eighty-seven players, divided into bi-annual age-groups, U12, U14, U16 and U18, performed two tests: Y-Agility Test, carried out in planned and reactive mode (Y-PLAN and Y-REAC) and Illinois for Change of Direction Test (ICODT). Difference between Y-REAC minus Y-PLAN represents the index of reactivity (REAC-INDEX).


RESULTS
MANOVA showed significant differences among groups (F3,182=14.591; P<0.01; η2p=0.244). Y-PLAN showed significant differences only between U12 and the other groups (P<0.01). ICODT results were significantly different between the groups U12 and U14 and the other groups (P<0.01). Significant Pearson's correlations between Y-TEST and ICODT, for the three categories of young players (0.398 P<0.05; 0.615 P<0.01; 0.608 P<0.01 respectively), were found, whereas no significant correlation was found in U18 group.


CONCLUSIONS
The best performance of Y-PLAN and ICODT, through age, depends on physical skill level, whereas the best RA results depend on technique and experience that help the players to use anticipatory skill. The high correlations between CODS and RA performances, differently than adult athletes, suggest that an effective work program for young players may include RA and CODS training at the same time.