As for cardio, you really need to do it correctly. Get a heartrate monitor if the treadmill doesn't have one, and pay attention to the HR charts on the machine. Start slowly and work your way up (warm up!) and STICK WITH the cooldown period at the end - they made that for a reason. If you just STOP, you're putting incredible strain on your heart. You really should get medical clearance before starting a serious cardio regimine...