The effects of two exercise regimens (intermittent and continuous endurance) on the fiber area, and capillarization of mice skeletal muscle (gastrocnemius) was studied. The training programs had a duration of 30 days, 5 days/week, and was performed on a motor-driven treadmill. The intermittent group performed the exercise at 16 m.min-1 with a slope of 5%. The continuous group performed the exercise at 16 m.min-1 with 0%. The fiber area and the capillarization was evaluated in the white portion of the gastrocnemius. A high degree of hypertrophy was observed, and a significant increase in the capillary density, capillary to fiber ratio, and in the number of capillaries sectioned obliquely and/or longitudinally was found. The results suggest that the endurance training, intermittent or continuous, induce cell hypertrophy, and an increase in capillarization especially, based on an alteration of the structural pattern.