Not going for your daily run is probably one of the hardest things for most dedicated runners to do. We become so accustomed to the way we feel that it’s almost impossible to tell when we are tired or needs rest or recovery. Here’s an article showing how Ryan Hall used an online tracking program to gauge his need for rest.
After disappointing performances in a couple of key tune-up races last fall, a depleted Ryan Hall made the hard decision to withdraw from the Chicago Marathon. Too many grinding 15-mile tempo runs at a five-minute-per-mile pace at 7,000 feet with too little rest afterward had finally caught up with him. “I love to push my body,” he says. “Recovery is the hardest part of training for me.”
Source: Time to Rest? | Runner’s World