I’m not sure how this has become so confusing. Maybe it’s all of the commercials and supplements and quick-fix information that is blinding us. I am going to attempt to simplify fat burning and exercise.
When we exercise at low intensities, there is a greater reliance of fat as a percentage of fuel source. This seems to have led people to believe that it must be more advantageous to exercise at low intensity if you want to lose fat weight. As the intensity of our exercise increases, our body relies less on fat and more on carbohydrate. One thing to remember is that we don’t have to be burning fat specifically in order to reduce our body weight. At higher exercise intensities, we burn more calories, so the amount of total fat used increases. What matters when it comes to weight loss is the rate or quantity of energy expenditure (calorie burn) rather than the percentage of energy derived from fat. And don’t forget, as we do more aerobic exercise training over time, our body adapts. We develop more mitochondria content and respiratory capacity improves, allowing for muscle carbohydrate sparing.