In the framework of positive psychology approach, the present study reports the effect of a mixed human resources (HR) intervention program. We developed an intervention by the integration of the classic resource-based intervention with the specific strength training program named FAMILY. Then, we examined the extent to which such a combined intervention enhanced commitment, work engagement, job performance, and decreasing exhaustion of the participants. N = 69 sales consultants operating in an Italian pharmaceutical company participated in our study. To monitor the interventions used, participants had to complete a diary with self-report measures on the dimensions considered for four weeks. Data were analyzed by using growth models to study the variability of the dimensions considered overtime. Afterward, we used multilevel model analyses to test the associations between them. Our results showed that our combined training intervention increased in-role and extra-role performance, emotional commitment, and decreased the reported exhaustion level of the employees. Moreover, relationships among such dimensions have been explored in relation to antecedents that affect them (i.e., negative and positive emotions experienced, and job demands, and resources).