The human body is really amazing. Although I am not a doctor I feel I can safely say this as someone who was forced to do 240 push-ups in about a 45 minute time span yesterday. I started take karate so I could safely beat up people in bars. Not that I would ever start a fight but I admit that I like the thought I can end a fight relatively easily. Let me tell you about doing 240 push-ups. After about 100 your shoulders ache but not nearly as bad as your hands and wrists do from holding your body up. I'm not a big man either--I only weigh 170. After about 150 your body starts to tingle. And not where you might expect. Apparently the human anatomy is such that when the body is under duress to makes certain "groinular" areas spasm. No, I'm not talked about my "bits" per se but that general reason. And, to further clarify, it's not a pleasant tingling. Every push-up makes the spasms more intense and more painful. By 200 your vision starts to cloud and your whole body writhes. Obviously your arms are shaking like a coke fiend as well. I gave out at 240 and I'm pretty sure that had a doctor been present he would have declared me dead. It was only thinking of my sweet dog greysmusic that brought me back (awww).