Agree with authors. I've treated patients for over 35 years with joint and muscle pain and the first thing I taught older patients especially was proper stretching technique. Forget bulking up, that's for young bucks. Floor exercises will provide all the muscle toning you need. Focus on joint ROM, flexibility and symmetry, balance, coordination, and regular walks that concentrate on correcting bad walking habits. Strangely enough I have found that many people must relearn how to walk properly.
Needless to say, I follow my own advice.