Intermittent claudication is a cramping leg pain that occurs during walking and is relieved by a short period of rest. It is caused by inadequate blood flow to the muscles of the leg due to atherosclerosis (hardening of the arteries). 
Can exercise therapy improve its symptoms?
Exercise therapy provides significant symptomatic benefit for patients with intermittent claudication. It seems to improve walking efficiency, induce vascular angiogenesis, reduce inflammatory activation, increase exercise pain tolerance, reduce endothelial and mitochondrial dysfunction, and metabolic adaptations within skeletal muscle. Further benefits of exercise therapy include reduction in cardiovascular risk factors such as diabetes mellitus, hypertension, and hypercholesterolemia. 
Exercise for intermittent claudication: which is the best approach? 
Supervised exercise therapy has been recognized to provide significant symptomatic benefit for patients with intermittent claudication, however it remains an underused tool and its widespread implementation is restricted by the lack of facilities and funding. 
Structured home-based exercise therapywith an observation component (e.g., exercise logbooks, pedometers) and walking advice are valid alternatives. 
The primary aim of this Cochrane Systematic Review was to provide an accurate overview of studies evaluating effects of supervised exercise therapy programs, structured home-based exercise therapy programs, and walking advice on maximal treadmill walking distance over time for patients with intermittent claudication. 
Secondary objectives were to evaluate effects of these three different programs on pain-free treadmill walking distance over time, quality of life, and self-reported functional impairment. 
Moderate to high-quality evidence shows that supervised exercise therapy provides an important benefit for treadmill-measured walking distance compared to home-based exercise therapy programs and walking advice. Although its clinical relevance has not been definitively demonstrated. 
Future studies should focus on disease-specific quality of life and other functional outcomes, such as walking behaviour and physical activity, and should be designed with long-term follow-ups.

Comment by Francesco Agostini