Background This prospective, randomized controlled clinical trial compared changes in exercise performance and daily ambulatory activity in peripheral artery disease (PAD) patients with intermittent claudication following a home-based exercise program, a supervised exercise program, and usual care control. Methods and Results Of 119 patients randomized, 29 completed home-based exercise, 33 completed supervised exercise, and 30 completed usual care control. Both exercise programs consisted of intermittent walking to near maximal claudication pain for 12 weeks. Patients wore a step activity monitor during each exercise session. Primary outcome measures included claudication onset time (COT) and peak walking time (PWT) obtained from a treadmill exercise test, and secondary outcome measures included daily ambulatory cadences measured during a 7-day monitoring period. Adherence to home-based and supervised exercise was similar (p = 0.712) and exceeded 80%. Both exercise programs increased COT (p < 0.001) and PWT (p < 0.01), whereas only home-based exercise increased daily average cadence (p < 0.01). No changes were seen in the control group (p > 0.05). The changes in COT and PWT were similar between the two exercise groups (p > 0.05), whereas the change in daily average cadence was greater with home-based exercise (p < 0.05). Conclusions A home-based exercise program, quantified with a step activity monitor, has high adherence and is efficacious in improving claudication measures similar to that seen with a standard supervised exercise program. Furthermore, home-based exercise appears more efficacious in increasing daily ambulatory activity in the community setting than supervised exercise.

Intermittent claudication is associated with lower total daily ambulatory activity owing both to less time ambulating and to fewer strides taken while ambulating, particularly at moderate and high cadences.

In patients limited by intermittent claudication, shorter ICD and ACD values are associated with reaching a minimum value in calf muscle StO(2) sooner during treadmill exercise and with having a delayed recovery in calf muscle StO(2) after exercise.

Purpose To determine the association between daily ambulatory activity patterns and exercise performance in patients with intermittent claudication. Methods One hundred thirty-three patients limited by intermittent claudication participated in this study. Patients were assessed on their ambulatory activity patterns for one week with a small, lightweight step activity monitor attached to the ankle using elastic velcro straps above the lateral malleolus of the right leg. The step activity monitor recorded the number of strides taken on a minute-to-minute basis, and the time spent ambulating. Patients also were characterized on ankle/brachial index (ABI), ischemic window (IW) after a treadmill test, as well as initial claudication distance (ICD), and absolute claudication distance (ACD) during treadmill exercise. Results The patient characteristics (mean ± SD) were as follows: ABI = 0.71 ± 0.23, IW = 0.54 ± 0.72 mmHg.min.meter−1, ICD = 236 ± 198 meters, and ACD = 424 ± 285 meters. The patients took 3366 ± 1694 strides/day, and were active for 272 ± 103 minutes/day. The cadence for the 30 highest, consecutive minutes of each day (15.1 ± 7.2 strides/minute) was correlated with ICD (r = 0.316, p < 0.001) and ACD (r = 0.471, p < 0.001), and the cadence for the 60 highest, consecutive minutes of each day (11.1 ± 5.4 strides/minute) was correlated with ICD (r = 0.290, p < 0.01) and ACD (r = 0.453, p < 0.001). Similarly, the cadences for the highest 1, 5, and 20 consecutive minutes, and the cadence for the 30 highest, non-consecutive minutes all were correlated with ICD and ACD (p < 0.05). None of the ambulatory cadences were correlated with ABI (p > 0.05) or with ischemic window (p > 0.05). Conclusion Daily ambulatory cadences are associated with severity of intermittent claudication, as measured by ACD and ICD, but not with peripheral hemodynamic measures.

Purposes To determine the walking economy before and after the onset of claudication pain in patients with peripheral arterial disease (PAD), and to identify predictors of the change in walking economy following the onset of claudication pain. Methods A total of thirty-nine patients with PAD were studied, in which 29 experienced claudication (Pain group) during a constant load walking economy treadmill test (speed = 2.0 mph, grade = 0%) and 10 were pain-free during this test (Pain-Free group). Patients were characterized on walking economy (i.e., oxygen uptake during ambulation), as well as on demographic characteristics, cardiovascular risk factors, baseline exercise performance measures, and the ischemic window calculated from the decrease in ankle systolic blood pressure following exercise. Results During the constant load treadmill test, the Pain group experienced onset of claudication pain at 323 ± 195 seconds (mean ± standard deviation) and continued to walk until maximal pain was attained at 759 ± 332 seconds. Walking economy during pain-free ambulation (9.54 ± 1.42 ml.kg−1.min−1) changed (p < 0.001) after the onset of pain (10.18 ± 1.56 ml.kg−1.min−1). The change in walking economy after the onset of pain was associated with ischemic window (p < 0.001), hypertension (p < 0.001), diabetes (p = 0.002), and height (p = 0.003). In contrast, the Pain-Free group walked pain-free for the entire 20-minute test duration without a change in walking economy (p = 0.36) from the second minute of exercise (9.20 ± 1.62 ml.kg−1.min−1) to the nineteenth minute of exercise (9.07 ± 1.54 ml.kg−1.min−1). Conclusion Painful ambulation at a constant speed is associated with impaired walking economy, as measured by an increase in oxygen uptake in patients limited by intermittent claudication, and the change in walking economy is explained, in part, by severity of PAD, diabetes, and hypertension.