Beginners should start by performing this pranayama technique for 30 seconds. This is done to see if you experience any severe strain in your abdomen. With regular practice, you can increase this time to 10-15 minutes. Also, practicing BOF for 5-15 minutes a day helps to purify the blood. Initially, target 1 round of breathing cycle per second which will increase to 2-3 cycles of breathing per second.