Background

People with peripheral arterial disease may experience symptoms of limb ischaemia. When this occurs with walking and ceases upon rest, it is termed intermittent claudication. Symptoms of limb ischaemia can range from aches, cramps, numbness or, more commonly, pain. These symptoms can manifest anywhere in the lower limb, although the most common site is the calf muscle due to insufficient patency of the superficial femoral artery.1 ,2 In addition, these symptoms limit walking capacity (speed and distance) and in turn lower the quality of life.3 ,4 Whether symptomatic or not, peripheral arterial disease is also associated with an increased risk of cardiovascular and cerebrovascular events, death, as well as accelerated rates of bone loss and increased fracture risk.1 ,5

Several types of intervention (often in combination) are used to improve walking capacity, including medication, surgery and exercise training.1 Previous systematic reviews have established that supervised progressive exercise training can improve both maximum and pain-free walking distances, and that it is more effective in this regard than unsupervised exercise training6 and usual care or placebo.7 Although the effect of supervision is therefore clear, less is known about the influence of factors such as the duration of the training, whether the walking is done on a treadmill, and what pain threshold, if any, is used to determine when to stop walking.8 A systematic review of randomised trials comparing exercise regimens that differ by one of these factors is being undertaken.8 Until this is complete, a less direct estimate …