Exercise and intermittent claudication. Blood flow in the calf muscle during walking studied by the xenon-133 clearance method

Nineteen patients with obliterative arteriosclerotic disease of the legs and suffering from intermittent claudication were studied before and during a 6 months' training program. The maximal walking distance and the calf muscle blood flow during walking (xenon-133 clearance technique) was recorded at monthly intervals. A significant correlation was established between improvement in maximal walking distance and a change on exercise toward more normal (that is, more adequate) blood flow in the calf. In particular, it was found that calf muscle blood flow during walking was increased by physical training. The data suggest that functional factors (for example, better coordination of the working muscles or a decrease of in-between-step intra-muscular pressure) as well as anatomic factors (increase in number or diameter of collateral vessels, or both) are involved in increasing collateral efficiency.