Found this online and thought I'd share. It looks great. Last year I couldn't do more than one regular full push up and now I can do lots, just because I kept pushing for that one extra push up. As soon as you think you can't do anymore, do one. You'll slowly build your stamina, core, and arm strength. Also, one of the things I do when I'm in weight-loss mode is when I find myself standing in the pantry doorway just staring at what to munch on, I go to the middle of the kitchen and do 10-15 push ups instead. When I stand up, I'm no longer munchie and I can move past the cravings to graze. (this only works sometimes, fyi). Another way to improve your push up count is to plank for 30-60 seconds. Just go to a high push up (keep your butt down!), head in-line with your spine and hold.
Here's the link: http://hundredpushups.com/index.html
