ta chi,stretch the muscles well before u start and this might help ,,walking is very good for u i would try a little if u can ,walking up and down the stairs a few times ,keeping a good posture through all of these will help in the long run ,i had the same when i started but i just pushed through it and now i swim 6 days a week and row 6 miles a day and find exceptional in helping with everything ,,but it does take a while to get back into it ,,,yoga is excellent for tuning and stretching the mu