500 push ups

jeez, how you manage that. it sounds impossible for the fact you say your skinny and not only that, but you can only do 500 push ups if you've built it up over time. its a repetitive excercise which you have to continuolusly build the right muscles up for. <--did that make sense
huge appetite is not neccesarily a good sign. it could be that your metabolism is really fast.