Treadmill Exercise
BehavioralTraining will be started conservatively with a goal of 15 minutes total duration at 40-50% HRR. Training target HR = %(HRmax - HRrest) + HRrest. HR max is defined as peak HR based on 2 maximal exercise tests at baseline. Individuals unable to walk continuously will exercise intermittently for several minutes as tolerated, with rest intervals, and advanced as tolerated with HR, blood pressure monitoring, and Borg Perceived Exertion to assess subjective cardiopulmonary exercise tolerance, as previously described. Treadmill training velocity will advance as tolerated by week 6 to a target intensity of 70-80% maximal HRR. Duration will similarly advance to a target of 30 minutes by week 6. Following week 6, the progressive training protocol will continue with attempts to increase velocity on a weekly basis and increase duration by 5 minutes bi-weekly to peak at 50 minutes. After week 6, the target HR goal will be 75-85% of HRR as tolerated by the subject.