Recent studies about interval training high intensity indicate that it is feasible to improve some parameters of health and fitness in different populations method. This study implements a complementary physical education program and aims to determine the effects of high-intensity training on basic physical abilities conditional in this population. Methods and Materials: The sample of 48 students was split into two mixed groups (men and women) between the ages of 14 to 18 years. A control group (G.C. = 25) and experimental group (G.E. = 23). The two groups were measured through pre-test and post-test, using indirect instruments of physical fitness; In turn, the G.E. was linked to a complementary program of high-intensity intervals of 8 weeks with a frequency of 2 sessions per week. They were applied training session in suspension (T.R.X.) and the second session with functional fitness exercises (E. F.). Results: It is determined that with a complementary program of high-intensity intervals of 16 sessions a statistically significant increase (p <0.05) in physical fitness tests of abdominal strength was found; trunk flexion; Course Navette and speed of 30 meters. However improvements were not statistically significant in testing Burpee and push-up. In turn, the G.C. who received only physical education class (2 hours per week) do not show significant changes in physical fitness tests. Conclusions: A complementary program to the class of physical education of training interval of high intensity, of 8 weeks and 2 times each one, based on the T.R.X. and E.F., it would be sufficient to produce positive adjustments in the physical condition of the teenagers, principally in the averages of abdominal force and the flexibility (Flexibility + 6,82 and abdominal Force + 12,65).