I don't want to sound like a lame celebrity but sometimes you have no choice and you gotta do what you can with what you have. Period. The planet is a really fucked place. There are no guarantees for perfect conditions. In fact, perfect conditions is a made-up term. It's a myth - nothing else, nothing more. The businessmen uses it all the time but since when are they the measure of spirituality. Ok! I know, you are tired of lectures. Go do your pull-ups now and if you don't have a pull-up bar don't immediately buy some kind of a door gym faggotry. Use a tree instead. Here's how it's done.