The objective of this study was to evaluate the impact of an after school program on healthy eating and an active lifestyle that involves parents participation in the fitness of primary school children. Thirty three children (6 boys / 27 girls) aged between 10 and 13 years were involved in this study. They participated in three workshops per week for 25 weeks. One to two sessions were devoted to physical activity and the third weekly meeting was specific to nutrition. Anthropometric measurements, muscle tests and the maximum aerobic capacity test were measured at the beginning and at the end of the 25-week intervention program. After the program, we found a significant improvement in most of the physical tests performed: grip strength (p=0.0015), seated sit-ups (p<0.0001), arm extensions (p<0,0001) and flexibility (p=0.0099). A significant improvement in the maximum aerobic capacity test was also observed (p=0.0002). This study demonstrates that a 25-week after-school intervention program is sufficient to improve the physical fitness of children.