A systematic review of high-intensity interval training as an exercise intervention for intermittent claudication

Intermittent claudication (IC) is the most common symptom of peripheral arterial disease, which significantly affects walking ability, functional capacity and quality of life. Supervised exercise programs (SEP) are recommended as first-line treatment, but recruitment and adherence rates are poor. The time required to complete a SEP is the most common barrier to participation cited by patients who decline. High-intensity interval training (HIIT) is more time efficient than current SEPs and therefore has the potential to overcome this barrier. We conducted a systematic review to appraise the evidence for HIIT programs for IC.

MEDLINE, Embase, and CENTRAL databases were searched for terms related to HIIT and IC. Randomized and nonrandomized trials that investigated HIIT for the treatment of IC were included, with no exclusions based on exercise modality, protocol, or use of a comparator arm. Outcome measures were walking distances, peak oxygen uptake, recruitment and adherence rates, and quality of life. The risk of bias was assessed using the Cochrane tool and study quality using a modified Physiotherapy Evidence Database scale.

Nine articles reporting eight studies were included in the review. HIIT seems to improve walking distances and oxygen uptake in relation to controls, with improvements attainable in just 6 weeks. When HIIT was compared with low-intensity exercise, it seemed that longer low-intensity programs were required to obtain similar benefits to those from short-term HIIT.

Initial evidence suggests that HIIT may provide benefits for patients with IC. Initially, pilot studies of low-volume, short-term HIIT vs usual SEPs are required. This strategy will allow for larger randomized, controlled trials to be appropriately designed and adequately powered to further explore the potential benefits of HIIT in IC.