I am a yoga teacher. I have class of seniors (65+) and a regular class of younger folks. I highly recommend yoga at least twice a week to keep your mobility and your circulation strong. The older you get, the more you need it! If you are starting later in life you may need some modifications, but even with mods the yoga is highly beneficial. If you can't get to a class but have cable TV, there are many good yoga workouts on there... usually very early in the morning. You can do it in the comfort of your living room. Classes with other people are much more fun, tho!
For spray basting I set up a couple of folding tables I bought at Walmart... 6 foot by about 30", that bend in the middle so they are easy to handle. I spray baste my quilts up on the tables (pushed together, side by side). It doesn't bother my back at all.