I have done twelve 20 minute sessions with 10 minutes rest in between in one day.
First session at 30 pounds and then at least 5 sessions at 40 pounds and then the rest at 30 with the last few at 20. I have been
hanging for several years now and hve worked my way up to this amount. Also, for the balance of such a marathon day I will hang with my ADH device at about 2 pounds.
I hve gained three inches in length over the last 2-3 years and will continue until I hit at least 10" NBP.
GO easy and work your way up to this if you choose to do it!