High-intensity Intervals Versus Low-to-moderate-intensity Exercise Training in Patients With PAD

Condition(s) studied

Investigational drug(s) / intervention(s)

High-intensity interval training group (HIIT): Exercise training sessions will consist in an alternation of brief periods (≤ 60 s) of work performed at high intensity and brief period of passive rest. Patient will be asked to complete 1 set of 10-15x60-s (or 2 sets of 5-7x60-s) walking intervals. The training intensity in the HIIT group will be set at ≥85% HRpeak recorded during the maximal cardiopulmonary exercise test. The training intervention will consist of 36 walking sessions spread over 12 weeks. Each training session will lasted 30-60 min. The training intervention will be performed on a treadmill (Cosmed T150, Itlay), which is equipped with harness and chest belt to secure the patients and prevents falling. Each session started with a 5-min walking warm-up and ended with a 5min cool-down. During all the exercise training sessions, HR of the subjects will be continuously monitored (Polar M430, Finland).

Low-to-moderate intensity training group (LowMod group): Exercise training sessions will consist in an alternation of periods of work performed at moderate exercise intensity and period of passive rest. The training approach of the LowMod group will be similar to the training prescription usually adopted in patients with claudication. The exercise training intensity will be set at ≤76% HRpeak recorded during the maximal cardiopulmonary exercise test. The training intervention will consist of 36 walking sessions spread over 12 weeks. Each training session will lasted 30-60 min. The training intervention will be performed on a treadmill (Cosmed T150, Itlay), which is equipped with harness and chest belt to secure the patients and prevents falling. Each session started with a 5-min walking warm-up and ended with a 5min cool-down. During all the exercise training sessions, HR of the subjects will be continuously monitored (Polar M430, Finland).

Study summary

Supervised exercise training (SET) is considered among first-line therapies for patients with symptomatic lower extremity peripheral artery disease (PAD), combined with general cardiovascular risk management, lifestyle adaptation and pharmacological treatment.

Although without clear consistency, the guidelines give recommendations in terms of claudication pain severity, SET volume, duration, and frequency. However, no or little guidance is offered as far as training intensity is concerned. Most of the previous studies on SET, in the context of PAD, did not distinguish between symptom intensity and common training intensity measures such as % of maximal heart rate (%HRmax), % of HR reserve (%HRR), % of peak oxygen uptake (%VO2peak), % of VO2 reserve (%VO2R), or the rate of perceived exertion (RPE).

In a recent meta-analysis, we demonstrated that both training modality and exercise intensity (based on %peak heart rate, %peak oxygen uptake, or the rate of perceived exertion) should be considered when looking for the best results in patients with symptomatic PAD. These results call for study of the individual roles of each exercise intensity and modality on walking performance and cardiorespiratory fitness in patients with symptomatic PAD.

High-intensity interval training (HIIT) is composed of brief bursts of vigorous intensity interspersed with periods of rest or low-intensity exercise. HIIT may be better than moderate-intensity training (MIT) in improving cardiorespiratory fitness and functional capacity in patients with cardiovascular and metabolic diseases, but in patients with symptomatic PAD, the effects of such modalities on walking ability and cardiorespiratory fitness remain to be clearly determined.

The primary objective of this study is to compare the effects of 12-week-long exercise training (short-duration high-intensity intervals vs. low-to-moderate intensity) on treadmill performance in patients with symptomatic PAD.

It is hypothesized that treadmill performance would be improved to a greater extent after high-intensity exercise training

Eligibility

Primary outcome measure(s)

• Maximal walking distance — This will be assessed before and after the 3-month training program. The post-program assessment will be performed between 5 to 14 days following the last training session.
  Patients will perform an incremental treadmill test to determine the maximal walking distance (MWD). Initial walking speed will be set at 3.2 km/h, and at 0% grade. The grade will be increased by 2% each 2 min.

Trial sites (1)

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