Relax and Recharge to Run Faster at Runner's World

Relax and Recharge to Run Faster at Runner's World: "Runners who sweat every detail of a workout—pace, distance, effort—may not think twice about a 'recovery day' on their training program. After all, rest is easy, right? But while some people are more than happy to take a day on the couch, others can't resist going for a bike ride or even a light three-mile jog. Which is best?"