Reproducibility of treadmill exercise in patients with intermittent claudication

The reproducibility of pain limited exercise time (ET) and heart rate (HR) have been evaluated in repeated treadmill exercise tests in 24 patients with arterial occlusive disease of the lower limbs and intermittent claudication. The protocol includes a walking speed of 1 m/s and load increments of 10 watt/min and the two tests were separated by 1--14 days. The total ET was systematically increased by about 30 sec (P less than 0.05) at the second exercise test. The reproducibility of ET at the onset of leg pains was 34%, whereas the corresponding value at maximal leg pain was 16%. HR at the termination of the test did not differ systematically between the two tests and the reproducibility of HR was 6.1% and 5.5% at the onset of pain and maximal pain, respectively. It is concluded that a slight improvement in walking capacity at a second exercise test must be taken into account when evaluating different types of therapy in patients with intermittent claudication and, furthermore, that ET, walking distance or work load, should preferably be evaluated at or near maximal leg pain.