I watched my son do a leg work out yesterday that had teenagers puking everywhere. My son's hockey coach is Eastern Block and builds successful teams. Yesterdays work out included a trip to the coast to the sand hills. A steep 400 yard sand dune that goes from about a 20% grade at the bottom to a 45% grade at the top. 1 hour and 45 minutes of sprints and hops up and down this hill at different lengths from about 15 yards to the full hill. Topped by a final run of 3 non stop trips up and down that must be completed in under 7 minutes. There were boys that literally passed out face down in the sand. It looked like a Navy Seal drill. My son and I prepared for the event by running stairs. We have a flight of 190 stairs near us and it makes for quite a work out. I run it 10 times but my sons kills it running it 10 X and then hopping it 10X. He finished the final hill event in under SIX minutes yesterday. I had to give him and atta boy on that one. He is going to have quads bigger than his dad by 16. His glutes are so muscular that I tease him that he has a black woman's butt.