Beneficial effects of exercise beyond the pain threshold in intermittent claudication

The quality of life and autonomy may be severely hampered in patients with intermittent claudication, but the amputation rate is very low. Supervised exercise training is effective, but still very rarely employed. Many authors think that in these patients exercise over the pain threshold may be dangerous. The aim of this study was to assess whether supervised, 3-month duration, 3 times/week, beyond the pain threshold exercise training is safe and whether it improves both the performance and quality of life in patients with claudication.

Forty-three patients with claudication, confirmed at Doppler study and/or angiography, have been evaluated by means of graded treadmill testing, the ankle-brachial pressure index at rest and after walking and a Walking Impairment Questionnaire before and after 3 months of treadmill training beyond the claudication threshold.

Patients showed an 86% increase in time to onset of claudication pain (p < 0.00001), a 50% increase in total walking time (p < 0.000001) and improved questionnaire scores of pain intensity (%, p < 0.005), distance covered (+87%, p < 0.005), speed (+42%, p < 0.05), and stair climbing (+25%, p = NS). The basal and post-exercise ankle-brachial pressure index was not modified by training. Analysis of all subgroups of patients ( 65 years of age, with/without coronary artery disease and diabetes mellitus, pre-training time to onset of claudication pain 3 min, with angiographic/Doppler occlusion or stenosis) revealed a statistically significant increase in both time to onset of claudication pain and total walking time.

Supervised physical training beyond the claudication threshold significantly improves the walking time and quality of life of patients with claudication.