To be able to take a fist in the anus requires a lot of practice and anus stretching exercises. There is no a time limit however it all depends on each individual body’s anatomy. Anal Fisting always requires knowing what you’re doing and the receiving party must have practiced the anus for bigger stuff. According to an Anal Fisting Research , successful Fisting requires an average of 1-1.5 years of training to be a Fistee.