Exercise and intermittent claudication. I. Effect of repetition and intensity of exercise

Four men with arteriosclerosis obliterans (ASO) were exercised on a treadmill on 4 different days to determine their maximal walking time (MWT) and the point at which their claudication pain (CPT) began. Each subject was exercised at 60%, 75%, and 90% of his MWT to determine the effect of work intensity on the systolic blood pressure at the ankle (AP). To measure the effect of exercise repeated on the same day, each subject walked five times each day on 4 different days at each of the three workloads. After each subject completed the required number of walks, his MWT was again measured on 4 separate days (one subject was retested only once) to determine whether it had changed. In every case the greatest reduction in AP occurred after the initial maximal walk but the submaximal intensities caused different responses in the different subjects. With repetition of exercise each subject displayed a progressive increase in either the AP level taken 2 minutes postexercise or the rate of recovery of AP to the pre-exercise level. There were significant increases in MWT, in CPT, and in the resting and postexercise AP levels in some of these subjects. This was most probably due to increased collateral circulation before, during, and after exercise.