Give this workout a try if you want to burn some fat and strengthen your core at the same time. Do each move for 40 seconds, then take a 20 second rest. Repeat each move before you will move on to the next.
This circuit of 10 moves will give you a total of 20 minutes of a workout. If you feel fierce and motivated, repeat it and you will end up with 40 minutes :) Enjoy your workout and let me know how you liked it and if you are interested in more of this stuff.