In his book on the similarities between writing and running, What I Talk About When I Talk About Running, Japanese writer Haruki Murakami brags that he never walked during a race. But walking during runs can be a valuable way to train and race.
Running guru Jeff Galloway has created a training method with walking breaks inserted into runs. This technique allows many to run farther and for longer with fewer injuries. The bottom line: walking is not for wimps. Try a walk-run treadmill workout to test the technique.