Aerobic exercise can be understood as fasting aerobic exercise when the last meal is more than 6 hours away, such as fasting aerobic exercise after getting up in the morning.

Yes, because on an empty stomach, our body's glycogen reserves are very low, and the proportion of fat energy supply is high. If it is low-intensity aerobic, the proportion of fat energy supply can even reach 70%.

It is recommended to do moderate and low intensity aerobic exercise on an empty stomach, such as brisk walking. For jogging, I suggest that the treadmill slope 12~ 16, the speed should be 3.5~4.5, and the intensity should not be too high, otherwise hypoglycemia and muscle loss will easily occur.

If you are afraid of lean muscles, you can eat some digestible protein, such as egg white and protein powder, before fasting (intake of protein will not have much influence on fasting state, blood sugar and insulin).