Fat is burnt mostly after the workout is over-How?

Workout in a low pulse (60%-70% over your normal pulse) burns
fat more effectively.
Workout in a higher pulse (75%-80% over your normal pulse) burns less fat but almost the same calories.
In a low pulse workout ,your body recovers fast after it. And the fat burning process will take place almost only within the workout time itself but not after it.
In a high pulse workout your body might burn less fat during the workout.But most of the fat burning process will take place for some time after you are done with the workout.
As an example we can compare two people both the same weight. Both workout for half an hour. Person1 works at low pulse and person 2 at high pulse. The difference between the amount of calories burnt at each of their workout time is actually negligible.
Fat is the major energy supply for the body at rest. And it will be used for body recovery after a strenuous workout.
We must understand that the fact that more fat is burnt at a low pulse workout does not mean it's a better way to lose fat or to lose weight. In both cases in the example above the trainers burned almost the same amount of calories after all. The body is a very sophisticated machine and it will take energy from where ever it's convenient to it.
At strenuous workout the body needs sugars or carbohydrates fast .It will burn more carbohydrates than fat. And after the workout is over the body will use fat and proteins (muscles) for it's energy supply if one does not eat properly. At a low pulse workout the body will use relatively more fat as it's energy source for the workout. Still it will use carbohydrates but comperativly less.
A more strenuous workout harms the muscles .There are small microscopical damages in the muscles that need to be fixed. Fixing takes place only at rest and uses the energy sources the body uses at rest. So after a strenuous workout we can say that relatively more fat is burnt. But also proteins and carbohydrates are needed for the fixing.
Again if one wont eat properly after a strenuous workout the body will use muscles to fix muscles. That is it will feed on it's own muscles and one will not lose fat but muscles.
One should workout at a pulse and intensity that is comfortable for him or her. A one that make you work but also one you can persist on for a long time. A workout that you can enjoy and not suffer.
The fact that more fat is burnt after the work out is almost always true .Again that is because the body's main source of energy at rest is fat.
For a situation that fat burning is significantly elevated after a workout one needs to run the marathon or the like. After such strenuous workout of about two hours it will happen. The body will keep on burning more calories that it's rest metabolic rate (RMR) for quit several more hours . Such workout is not something one can do on a regular basis not even Olympic athlete. Such strenuous workout is not the way to speed metabolism rate on a everyday basis or to lose weight.