PAD is a condition that occurs when atherosclerotic plaque builds up in the peripheral
arteries and restricts blood flow. People with PAD often experience reduced blood flow to the
legs, which may cause painful leg cramping while walking, known as intermittent claudication.
Claudication affects over 4 million people in the United States, and many people with this
condition can walk only ½ to 2 blocks before leg pain begins to occur. Regular treadmill
walking has been shown to be effective at increasing walking distance and reducing
claudication in people with PAD. However, walking on a treadmill may prove difficult for some
people with PAD and usually causes increased leg pain, both of which may reduce exercise
frequency. Aerobic arm exercises do not cause leg pain and may be an effective way for people
with PAD to improve overall cardiovascular fitness and increase the amount of exercise they
do. The purpose of this study is to compare the effectiveness of a treadmill exercise program
and an aerobic arm exercise program at reducing symptoms of claudication and improving
walking ability in people with PAD.
This study will enroll people with PAD and claudication. At a baseline study visit,
participants will complete a treadmill walking test; a blood collection; and questionnaires
to assess walking status, daily activity levels, quality of life, and mood. One week after
the baseline visit, participants will attend a study visit for an assessment of forearm and
leg muscle blood flow and a hand-bike test that will measure upper body strength using an arm
cycle ergometer. The ergometer is a device with bicycle pedals that people move using their
arms. Participants will then be randomly assigned to either a treadmill exercise training
program, an arm ergometry exercise program, or a control group.
Participants in the treadmill exercise training program will attend a supervised program at
one of four study sites and exercise on a treadmill for 1 hour three times a week for 12
weeks. Participants in the arm ergometry exercise program will attend a supervised program at
one of four study sites and exercise using an arm cycle ergometer (hand-bike) for 1 hour
three times a week for 12 weeks. Participants in both groups will also receive written
instructions about exercising on their own. Participants in the control group will continue
to receive usual care from their regular doctor for the treatment of PAD and will be provided
with written exercise instructions. Once a week for 12 weeks, participants in the control
group will attend study visits to discuss any health problems.
All participants will be asked to monitor their daily exercise for 3 separate weeks during
the 12-week period by wearing an accelerometer, which will measure and record physical
activity. They will also record their exercise habits in a written diary. All participants
will attend study visits on 2 separate days at Weeks 6 and 12 for repeat baseline testing.
From Weeks 12 to 24, all participants will be encouraged to continue to exercise on their own
at least three times a week for 30 minutes. Every 4 weeks, study researchers will call
participants to offer encouragement and answer questions. At Week 23, participants will again
wear an accelerometer and keep an exercise diary for 1 week. All participants will attend a
final study visit at Week 24 for repeat baseline testing.
