If you want to really bring up your conditioning and lose body-fat you need to get your ass off the stair stepper and treadmill and start moving. Sprints, Prowler pushes, jumping rope, sled drags, sandbag work, sledgehammer swings and bodyweight exercises are far more effective than any "cardio" machine could ever be.
A great exercise to really bring up your conditioning rapidly is the burpee/chin up combo. You perform a burpee and then at the top of each rep you jump up into a chin up. The higher the chin up bar, the better. Try performing a few sets of this at the end of your strength workout or as part of a conditioning circuit mixed in with some mountain climbers, grasshoppers, slalom jumps and jump rope sprints.
One note to be aware of when performing a regular burpee or burpee/chin up combo is that you don't want your hips to sag when you are in the bottom with your legs fully extended. This puts undue stress on your lower back and can lead to injury.
Give these a try today and let me know how they work out for you.
And, for more incredible conditioning methods, don't forget that Fit to Fight comes out tomorrow.
Unfortunately the tape ran out before he puked after rep number 21.