I'm a 75 year old male. I have two replacement knees, I have had three bladder cancers, I have a degenerative lumber spine but I still would like to keep fit. I walk my two dogs two or three times a day and try to eat healthily. I don't smoke or drink now, although I did smoke up to being 40 years of age.
Can anyone advise me on what exercise I could do to improve my fitness.