[Morphology of human skeletal muscle and its adaptability to different training conditions]

Endurance exercise training improves the oxidative capacity of the muscles directly involved in training. Structurally we find an increase in capillary supply and an enlargement of the mitochondrial compartment of muscle fibers. In contrast, strength training increases the muscle fiber's content of contractile proteins at the expense of the oxidative structures. Both types of training enhance substrate content of muscle fibers. In strength training we find more glycogen, in endurance training more lipids and more glycogen in trained muscle fibers.