Doing crunches & pushups ......................?

The best thing you can do is see how much push-ups you can do... Go until you almost max out.That will become your baseline. If you really want to improve...Let's say you max out at 22 well over the entire day do 5 sets of 22. Everyday try and increase to reps and reduce the sets (staying around 100 a day). If you can't increase that day then do the same and try for the next day. Inno tme at all you will be able to do upwards of 60 70 push-ups.