When my POIS was bad I only had sexual activity once a month. So when I masturbated I knew I have to wait for a month to get the same feeling. So it took 4,5 or even 6 hours before I had the O. Since I only have 1 day of extreme POIS I can have the sexual activity more often. But I still was busy for hours. I found out that if I masturbate for only 2 to 3 hours my POIS isn’t so extreme when I do sessions of 6 hours. But maybe this doesn’t have to do with POIS. But it’s just unhealthy for your joint, your back to do this for 6 hours. So my advice is shorten the time to max 2 hours.