I was a heavy weightlifter for over 29 yrs (56 tons total per workout) and I was kayaking a lot also. My right shoulder started giving me pain so MRI and scoping was done. They determined i had several tears in the shoulder. It was operated on and they found that i had totally destroyed all the cartledge which they removed along with a small bone spur. they also found a bit of arthritis. they camelized the bone and said since it was not a weight bearing joint it would probably not cause me any problems they were right its been fine i still kayak and road bike without any discomfort. I did wait a full six weeks before doing any rehab which lasted for 8 weeks. after rehab i still would get some discomfort but that has since past. I no longer weight lift thought Good luck on your surgery I'm sure it will come out fine glenn in phx