To examine the effects of a gamification teaching program, including the use of a game-based mobile app on the cardiorespiratory fitness (CRF) levels of college students. This study included a total of 117 college students (20.1 ± 2.9 years). They belonged to two different class groups, one formed the intervention group (IG,  = 58) and another one the control group (CG,  = 59). IG college students followed a 16-week gamification teaching program focused on encouraging physical activity (PA) through a game-based mobile app. The program was named "$in TIME" and set in the "In Time" science fiction movie. Each student belonging to the IG had a countdown on their mobile app so they had to perform learning and PA challenges to gain time. Thus, they had to run or cycle 3 to 5 days per week to gain time of life. The CG followed a traditional teaching methodology instead. CRF was assessed preintervention and postintervention using the 20-meter shuttle run test (20mSRT). The stages completed in 20mSRT and the estimated maximal oxygen consumption at postintervention were significantly different between groups ( < 0.001,  ≤ 0.7), with a mean difference of 1.2 stages and 3.69 mL/(kg·min), respectively. Analysis within group showed a significant pre-post improvement only in the IG of 1.4 stages ( < 0.001). A gamification program, including the use of a game-based mobile app in a university setting, had a significant effect on the CRF in college students, in comparison with a CG that follows a traditional teaching methodology.