Local versus systemic mechanisms underlying supervised exercise training for intermittent claudication.
The mechanisms by which exercise training improves intermittent claudication remain unclear. In this article, the effects of local and systemic physiological factors on improved exercise tolerance after a supervised exercise program in claudicants are investigated. A total of 60 patients were randomized to 3 months of supervised exercise followed by 3 months of unsupervised exercise, or to exercise advice alone (control). Supervised exercise increased both pain-free and maximal walking distances. Heart rate during submaximal exercise and resting mean arterial pressure were lower after supervised exercise at 6 months. Serum lactate at maximum claudication increased significantly after 3 months in the supervised exercise group but this change had resolved by 6 months. Symptomatic improvement was accompanied by modest reductions in mean arterial pressure and submaximal heart rate on exercise. Increased serum lactate at maximum claudication subsequently declined despite continued improvement in walking distance, suggesting local adaptations to improve efficiency of muscle oxygen delivery and/or utilization.
Stewart
Andrew Hr
AH
Department of Vascular Surgery, Bristol Royal Infirmary, Bristol, United Kingdom.
Smith
Frank Ct
FC
Baird
Roger N
RN
Lamont
Peter M
PM
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D005081:Exercise Therapy; D017079:Exercise Tolerance; D005260:Female; D006339:Heart Rate; D006801:Humans; D007383:Intermittent Claudication / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D016138:Walking
D015415:Biomarkers; D019344:Lactic Acid