Controlled "FALL"ing forward
Many athletes have heard me define proper running form as "Controlled Falling Forward". I say this to emphasize the need to keep your center of gravity slightly forward as if falling and the legs are used to convert that energy into forward motion with as little resistance as possible to maintain the momentum. I often work with people who have forgotten this natural human movement for whatever reason. Landing on the heel with the knee straight does nothing to keep the momentum and in fact, requires more energy to overcome the stoping motion that has occurred. In this time be sure to hit the trails more often and take your shoes off occasionally (for only short distances) and re-learn how to run the way you were intended. Short, quick & effortless steps that don't resist you but invite you, to keep going further and faster!