The goal was to assess the connections between vigorous physical activity (VPA), approach-avoidance temperament and depressive symptoms. Two studies were conducted. Study 1, correlational, to assess the mediating role of both dimensions of temperament, approach-avoidance contrast, between physical activity and depressive symptoms. Participants, 335 college students, completed the International Physical Activity Questionnaire, the Depressive Symptoms Scale (DSS) and the Approach-Avoidance Temperament Questionnaire (Ap-AvTQ). Results showed that approach-avoidance contrast could be considered a potential mediator between VPA and depressive symptoms. The global model was significant, F(2, 351)=3.22, p<.001, R2=14.91%, R2 adjusted=14.42%, and the bootstrapped upper and lower limits did not contain zero with the lower limit at -.05 and the upper at -14, suggesting a connection between VPA and depressive symptoms mediated by the approach-avoidance contrast temperament. Study 2, longitudinal, to test if a physical activity program could produce changes in approach-avoidance contrast temperament, manipulating the depressive symptoms. A VPA program was conducted with 149 college students. Participants completed the DSS and the Ap-AvTQ. The true intraindividual change modeling technique, a more direct approach to modeling interindividual differences in intraindividual change without using a control group, showed that participants’ depressive symptoms were predicted through the mediation of the approach-avoidance contrast temperament (γ=-.36, p<.001). VPA was positively linked to the approach-avoidance contrast temperament that was negatively connected to depressive symptoms, and negatively linked to the approach-avoidance contrast temperament that was positively connected to depressive symptoms. It seems possible to influence depressive symptoms through approach-avoidance contrast temperament using VPA.