So the gym in my apt. complex got vandalized and has been closed for the last 4 months. So i decided to do only calethestics in the meantime (mainly push ups, crunches, and pull ups in my basement). Over the past 4 months, I've gotten in better shape just doing these exercises, where as before I would go to the gym and lift like crazy lifting and using all the high tec machines. Why is this?