PURPOSE: To evaluate the impact of an intervention to promote healthy lifestyles among medical students at Universidad de los Andes in Bogota, Colombia. METHODS: A longitudinal, exploratory study was conducted between May 2014 and June 2015. The sample contained 156 medical students enrolled in the Medical Physiology course. The curriculum intervention comprised a healthy lifestyle promotion strategy. One class was dedicated to Exercise Physiology. Students were asked to conform groups to research topics related to PA, nutrition and tobacco. The professor gave a formative sport incentive (10% of the final grade) to the student who regularly practiced PA and adopted healthy behaviors during the semester. A quantitative approach was used to measure health and fitness-related variables (i.e. BMI, Body fat, VO2max, Handgrip strength, Sit-up strength) at the beginning and at the end of the course. A qualitative approach was used to assess perceptions about the curriculum intervention and PA practices. Data was collected through self-reported evaluations (n=130) and semi-structured interviews (n=36). RESULTS: Of students, 57% were females, with age average of 20±1.5 years. Body fat decreased in 1.24% [CI: -1.81 to -0.67; p-value<0.01], estimated VO2max improved in 3 ml/kg/min [CI: 2.45 to 3.57; p-value<0.01]; Handgrip strength increased in 2.8 kg [CI: 1.83 to 3.83; p-value<0.01]; and Sit-up strength in 30 seconds increased in 3 Sit-ups [CI: 2.43 to 3.7.2; p-value<0.01]. No differences observed in BMI. All students reported to have practiced PA during the semester –on average three times a week– influenced by the curriculum intervention; particularly the academic incentive and physical fitness tests. Students reported to practice a vast variety of PA activities –sports, workouts, aerobic– mainly accompanied by friends, classmates and family members. Lack of time was the main barrier to practice PA. The intervention increased student’s recommended levels of PA (83% students post class compared to 36% students pre class). CONCLUSION: A minimal curricular intervention was effective in improving medical students’ personal PA habits and fitness. It remains to examine whether achievements of healthy lifestyles among students are maintained over time.