Most of us know that if we want to improve, we must stress ourselves in some of our training sessions. Exercise stresses the muscles, stimulating them to grow stronger and work more efficiently. Without enough rest after the stress, however, the muscles are driven to exhaustion or injury. Stress must be balanced by rest in sufficient quantity and quality for adequate growth.
Hard or long runs must always be followed by several easy days in which the pace or distance is reduced. In addition, you must build rest weeks into your program: every second or third week, you should automatically reduce total mileage. This gives your muscles the extra time to "catch up."
Improvement is based upon the quality of your speedwork and the length of your long run. By taking a day off and then running easily between these two "quality days" you will recover, rebuild stronger and reduce the chance of injury. Common mistakes that lead to injury are
* Trying to attain a high mileage level week after week
* Running daily runs too fast
* Not enough rest