Is anyone familiar with "Hair Shirt" training in IMA, where the practitioner can take enormous amounts of physical punishment. I believe it is similar to Iron Shirt.

I practiced this Gung for 8 years; lived out in the Bush sans plumbing, electricity, or any of the services most city dwellers take for granted. It was, indeed, enourmously punishing. I highly recommend it if your tastes run to masochism.

My neighbor practices this. I always see him in that same orange Hawaii shirt. He can't take his shirt off or else he rips his pit hair out!