Why Exertion Leads To Exhaustion

http://www.sciencedaily.com/releases/2007/12/071220103702.htm --- ScienceDaily (Dec. 28, 2007) — Scientists have found an explanation for runners who struggle to increase their pace, cyclists who can't pedal any faster and swimmers who can't speed up their strokes. Researchers from the University of Exeter and Kansas State University have discovered the dramatic changes that occur in our muscles when we push ourselves during exercise.