No doubt you have to be strong!
Physics says a 45 degree lean means the rider has to pull 1G* lateral to stay upright. A 60 degree lean means the rider has to pull 2G*. A 70.5 degree lean means 3G*. I've seen Bordy lean over more than 45 degrees, on ice, riding switch, and blowing past me. ;)
* All these numbers are pure lateral acceleration, not a combination of cornering force plus earth's gravity. Those numbers would be 1.41G, 2.24G, and 3.16G respectively.