Oh, my YES! I totally was there (same starting stats - 50 years old, 215 and 5'4"). I had so much trouble with my lower back!
Now - absolutely pain free! I started with walking, some very basic yoga and lots of chair exercises. I slowly added some WATP DVDs and then some other low-impact DVDS. I really like workout DVDs because I could pause them if I needed a rest. I could also modify any exercies if I needed, and slowly build up to "full" participation.
I'm here to tell you that at 51 1/2, I am totally pain free, able to walk 10-15 miles and feeling 20 years younger.
You CAN do this!!!
Really!
