I did both my lower legs each in one 8 hour session and my left and right side chest in each 4 hours sessions. Also my arms were front and back in a couple of 4 hours session. Let's see. What else. Hmm. Neck. Back and sides. About 3 hours. Around the nipples hurts like hell and some areas on the back of the calve but probably because my endorphins were burnt out from the long session. Neck wasn't so bad. Arms were like a piece a cake. Upper back. Not so bad. I guess I'm kind of saving the best for last. Still have to finish up my back and then the ribs too. Damn! Probably eventually do thighs too. Oh and the shins did hurt. Anywhere where there's bone is gonna hurt like hell. Everyone's pain tolerance is different so it's hard to say, but as a general rule, think bone so top of hands, feet, ribs, shin, head, elbows and kneecaps. But there are also some other tricky areas like the butt and around the genitals that will surprise you. I'm no expert. I'm still a work in progress.