Do any of you guys (body builders) do any sprinting? I find that guys who add a sprint routine once a week or so get more clearly defined muscles. I reckon its because of the great forces that go through the body, and the natural motion that sprinting is. Have you ever seen pics of Dwain Chambers or Shawn Crawford? These guys are huge, and what they mostly do is sprint (with weights as an addition to help with the strength and explosiveness). And they no doubt add a few cycles in too. What are your thoughts as body builders?