HIIT, High-Intensity Interval Training, mobilizes or breaks down a lot of fat from adipose tissue stores. It's super effective in this regard, but the thing is, just because fat is mobilized and enters the bloodstream doesn't mean that it gets burned. That's right, you can break down a lot of fat doing intervals, but then have a bunch of it go right back to where it came from.
Steady-state cardio (SSC) isn't nearly as effective as HIIT at mobilizing fat from fat stores, but it's really effective at burning those triglycerides that are floating around the bloodstream as a result of high-intensity intervals. Post-HIIT SSC is insurance that the fat that was mobilized gets burned.
How to Put This Strategy Into Action
Do at least 20 minutes of steady-state cardio after your intervals. The intervals could be anywhere from 10 to 20 minutes.
Here are a few examples: If you've got 30 minutes to do cardio, try 10 minutes of HIIT followed by 20 minutes of SSC. If you've got an hour, try 20 minutes of intervals followed by 40 minutes of SSC.
As for methods of cardio, let your imagination go wild. Try 20 minutes of intervals on the StepMill followed immediately by 40 minutes of walking on the treadmill at a slight incline. If you're doing your cardio outside, you could do sprints followed immediately by walking or jogging, depending on your cardiovascular shape.