Yes, 24 hours on a moutain bike is crazy. It can reek havoc on your body. You have to do things to insure your body against constant breakdown. Hip abductors must stay loose and strong or IT band issues will creep in. Core endurance and psoas flexability must stay high or low back pain will be a constant companion. Thoracic mobility must be constantly worked on or levator scapula/upper trap tightness will follow each ride. It's the little things done constantly that allow athletes to compete healthy and stay in contention for any type of championship.