I've personally been kicking my own ass with these exercises for a couple weeks now, so I can vouch for their ability to make you work hard. The nice thing is that they're all very scaleable to different levels and don't require any workout gear. There are countless circuits of similar exercises across the internet, but I worked this set up myself over some trial and error to get every major part of the body going in less than half an hour. I'm in reasonably good shape and