Twenty-four male rats were divided into four groups, with anabolic
steroids and exercise as variables. Biomechanical tests and histological
evaluations were performed. The results of the biomechanical tests
suggested that anabolic steroids produce a stiffer tendon, which fails with
less elongation. The energy at the time when the tendon failed, the
toe-limit elongation, and the elongation at the time of the first failure
were all affected significantly. Changes in the force at failure were not
statistically significant. No alterations of structure were noted when the
specimens were viewed with light microscopy. Alterations of the sizes of
the collagen fibrils were noted on electron microscopy.