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 evaluated with specific emphasis on the effects of exercise rehabilitation on the slow component of V̇O₂. Because the slow component of V̇O₂ represents an increase in V̇O₂ despite 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 treadmill 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 V̇O₂ during the treadmill test was defined as the difference between the end-exercise V̇O₂ and the V̇O₂ observed at minute 3. Ankle/brachial systolic pressure index (ABI) was measured before and immediately following the exercise test. Rehabilitation consisted of 3 d · wk^-1 of treadmill walking for 15-30 min at 60-70% of V̇O(2peak). The slow component of V̇O₂ and end-exercise V̇O₂ 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 mL · kg^-1 · min^-1; P < 0.05). Exercise rehabilitation also significantly (P < 0.05) increased the post-exercise ABI (pre-rehabilitation = 0.36 ± 0.26, post-rehabilitation = 0.43 ± 0.25). These data suggest that 4 months of exercise rehabilitation: 1) improves walking economy in PAOD patients because of a decreased slow component of V̇O₂, and 2) increases post-exercise ABI.