It is impossible to specify the time, and there is no such problem afterwards. As long as you exercise, your body begins to change without feeling. If you want to lose weight, you need to grasp the strength and time, but if you ignore the most important thing-diet, it will not be very effective. If you have good eating habits, you will almost see that your body fat is decreasing every day.

Of course, if you lose fat with oxygen, you need more ways than a single one.