IMPROVED WALKING ECONOMY IN PATIENTS WITH PERIPHERAL ARTERIAL OCCLUSIVE DISEASE

The effect of exercise rehabilitation on the oxygen cost of ambulation in patients with peripheral arterial occlusive disease (PAOD) was eva luated with specific emphasis on the effects of exercise rehabilitatio n on the slow component of (V) over dot O-2. Because the slow componen t of (V) over dot O-2 represents an increase in (V) over dot O-2 despi te constant-intensity exercise, it can profoundly affect the relative energy cost of exercise in individuals with a low functional capacity. Twenty-six patients with intermittent claudication performed treadmil l walking at 2.0 mph/0% grade for 20 min or until maximal claudication pain before and after 4 months of rehabilitation. The slow component of (V) over dot O-2 during the treadmill test was defined as the diffe rence between the end-exercise (V) over dot O-2 and the (V) over dot O -2 observed at minute 3. Ankle/brachial systolic pressure index (ABI) was measured before and immediately following the exercise test. Rehab ilitation consisted of 3 d. wk(-1) of treadmill walking for 15-30 min at 60-70% of (V) over dot(2peak). The slow component of (V) over dot O -2 and end-exercise (V) over dot O-2 at pretraining (0.75 +/- 0.90 and 11.12 +/- 2.10 mL.kg(-1).min(-1)) were significantly reduced after 4 months of exercise rehabilitation (-0.07 +/- 1.11 and 10.07 +/- 1.80 m L.kg(-1).min(-1); P < 0.05). Exercise rehabilitation also significantl y (P < 0.05) increased the post-exercise ABI(pre-rehabilitation = 0.36 +/- 0.26, post-rehabilitation = 0.43 +/- 0.25). These data suggest th at 4 months of exercise rehabilitation: 1) improves walking economy in PAOD patients because of a decreased slow component of (V) over dot O -2, and 2) increases post-exercise ABI.