Some of the most efficient fat burning work out is to follow a proper cardio exercise along with proper diet plans. You can try for walking on the tread mill at an average speed and then slowly increasing the speed and then slow jogging on it. You can also do cycling which is a very good exercise for burning your fats and calories. You can adjust the different levels of cycling and thus make the difficulty level more and burn more fats. If you can't afford gyms then you can go for a normal morning walks and running or also try few of the abs exercise.