As you can see from the chart above, doing abdominal exercise like crunches and sit ups actually burn the least fat before and after exercise. While doing stationary bike, treadmills or other cardio machine exercises may burn a lot of bat during the exercise itself but the after burn effect is minimal as compare to the more strenuous exercise like weight training. The blue bar shows the calories burnt during exercise while the red bar represents the calories burnt after the exercise.
After burn exercises are training that involve the combination of strength and cardio exercises with high level of intensity for a certain period of time. For example, alternate sets of 15 push-ups, 15 crunches and 15 seconds military jog (jogging on the same spot with out moving forward) repeat for 5 minutes without rest in between. We can also use cardio machine like stationary bike, alternating high and low intensity intervals in our pedaling. Or even go to the extreme of doing a mixture of swimming, cycling and jogging like that of a triathlon to intensify our workouts a bit. After burn exercise is a free choice exercise as we can use our own creativity to design our own workout that fits us best. This kind of training is so intense that our body's energy reserve, namely the glycogen is used up. Without any glycogen, our body will turn to our fat storage in our body for extra fuel. This fat burning process is a very slow process which is why we will feel tired as the strenuous exercise continues. The metabolic activity in our body will continue to run even after we have stopped the exercise as our body needs to replenish the glycogen storage by burning more fat tissue. With this knowledge of how effective fat burning works in our body, we can save time doing the right kind of exercise and get the result we most wanted without wondering around like lose sheep in the field with no changes to our physique what s ever in terms of our fat losing regime!