Similar to other yoga routines and spiritual practices, an empty stomach is better. Hence, you might want to do your mudra an hour or two after you eat or before breakfast, lunch or dinner. When your stomach is full of food, it can make it more difficult to concentrate because your body is going through digestion. The body usually takes about two to three hours to properly digest food. It requires blood during that time. Hence, it’s best to have your stomach void of food so that you can fully tap into and release the energy from your fingers into your body.