Abdominal strength is very important to have. What is strength though without control? Control of the abdominal muscles leads to the ability to move the organs underneath. Here you will observe me practicing first Uddiyana Bandha (upward abdominal lock) and then later Nauli (abdominal rolling). These are two very powerful cleansing exercises and not for the average practitioner. Make sure to only practice these on a completely empty stomach and not to overdo them.