Effects of supervised treadmill walking training on calf muscle capillarization in patients with intermittent claudication

The aim of this study was to evaluate the effects of supervised treadmill walking training on the calf muscle capillarization in patients with intermittent claudication. The first 12-week period was a nonexercise, within-subject control stage, and the second 12-week period was an exercise training stage. Calf muscle biopsy and functional capacity measurement were performed at baseline, preexercise and postexercise training. In all, 11 subjects completed all procedures. Their average age was (mean +_ standard deviation) 73.9 +_ 5.5 years and resting ankle-to-brachial systolic blood presure index was 0.57 +_ 0.11. After exercise training, the difference between the pretraining and posttraining capillaries in contact with type IIx and IIa muscle fibers for each subject was significantly correlated with an improved pain-free walking time, r = 0.69 and r = 0.62 (both P <.05), respectively. This finding suggests that the change in calf muscle capillarization might contribute to the improved walking capacity following supervised treadmill walking training in patients with intermittent claudication.