Treadmills or charts cannot tell you what type of calories you are burning while you exercise. Your body can burn protein, carbohydrate or fat and what you burn depends on your last meal.
For example, if you eat a fat-free muffin before you exercise, you will burn the fat-free muffin while exercising (as opposed to body fat!) and this would defeat the purpose.
Eat you drink too many carbohydrates, such as Gatorade before you exercise, you will burn Gatorade while you exercise.
Eat too few carbohydrates before you exercise (such as the Atkins diet, keto diet or fasting diets), then you burn muscle while exercising.
If you have a balanced Core Fat Loss meal prior to exercising, your muscles will burn fat as their primary source of energy.
To strengthen your body and to turn yourself into a fat burning machine, food is the most important factor to consider. Food controls your hormones which are the traffic controllers that determine which nutrients (protein, carbohydrates or fats) get thrown into the energy fire of the body. Are you burning fat at the gym? This is a question you have to ask yourself every time you eat. Each meal holds the power that determines which nutrients are thrown into the energy fire or not.
The only thing your body cares about is moment to moment blood sugar control, from the time you are born to the time you die, you must have a constant level of carbohydrates feeding your brain and central nervous system. If not, your body will turn to protein. Its important to note, the brain cannot burn fat.