The aim of this study was to assess the long-term effects that the manipulation of the motivational climate can produce on social factors, psychological mediators, motivation and behavioural consequences. 283 student-athletes with ages ranging from 14 to 18 years (M = 13,54 ± 1,31) completed a questionnaire that included the BPNES, the PLOC, the subscales cooperative learning and improvement of the PMCSQ-2, as well as persistence, effort and boredom subscales. Epstein's TARGET strategies were applied to the experimental group during 12 weeks by specially trained coaches. The repeated measures MANOVA showed significant changes in all variables in the experimental group in post-test 1.Furthermore, these changes were maintained in most variables six months after the intervention (post-test 2). No significant changes were observed in the control group. Finally, the results are discussed and future lines of intervention are proposed.