The inducible isoform of the 70 kDa HSP-family, HSP 72, has been shown to protect cells from protein-damaging stressors. In this experiment we wanted to investigate the effect of eccentric work, in the form of downhill running on a treadmill, on the induction of HSP 72. After familiarisation to the treadmill, rats were randomly assigned into two groups: resting controls and exercise. The exercising rats ran as long as they were able to, the gradient and velocity having been progressively increased, and were then taken off. Musculus epitrochlearis was removed bilaterally from both the resting controls and the exercising group. Western blot analysis showed no difference between the resting controls and the exercising animals. It seems therefore that this single bout of exercise was not sufficient to induce HSP 72 in musculus epitrochlearis.