Any exercise on an empty stomach can be beneficial for the body. It can help to burn fat more quickly, as the body is forced to use fat stores for energy instead of carbohydrates. It can also help to increase metabolism and may result in improved muscle growth. Additionally, exercising on an empty stomach can help to build discipline and help to create a healthy routine. However, it is important to remember that exercising on an empty stomach can lead to fatigue and dizziness, so it is important to ensure that you are well hydrated and have eaten a balanced meal prior to exercise. Additionally, it is important to listen to your body and stop if you feel any pain or discomfort.
But in the case of kapalbhati, since it is an abdominal exercise which use your abdominal muscles to push out expired air, it is better to keep empty stomach. And empty stomach means that you have not eaten anything in the morning and you have attended to natural call in the morning. In the evening, there is a gap of 3-4 hours after you have taken good amount of meal in the noon.
