I hiked a peak this summer with a guy that was 65 who had polio as a child. Right foot/ankle was locked/malformed from the bug but was basically kicking my ass climbing 5k feet of vertical in about 2.5 hours time to the top. He stays very active and doesn't let the issue get to him. I'd say hard exercise is what enables him to do activities like climbing peaks in the first place. He did not mention whether or not he had spinal issues.
