One of the surest ways to maintain independence and mobility for as long as possible is to stay active. Both the body and mind follow the saying, "Use it or lose it!"
If you are fortunate to have a recreational center or seniors center nearby, check for specialty fitness classes designed for elderly people. These could include, chair assisted classes, gentle classes, or specialized classes for people over a certain age. If you at all concerned, talk to the fitness instructor ahead of time. They should be trained enough to either assist you or point you in the right direction for more information.
I have included a starter video here that is meant as a very short and gentle stretch, something most people could perform everyday. Depending on the current fitness level of your loved one, this may already be a challenge or they could be ready for a more complete workout. Please excuse the help I received from the performer's 3 cats. Apparently they've never seen a tripod because they were fascinated by it. Think of it as a more authentic experience!
I plan to add more videos with various chair-assisted and gentle workouts (please use the contact form or comment in our forum if you have requests). You can also find some great at- home exercises on YouTube. Always remember when working out at home, the instructor can not watch you, therefore, it is very important that you know and respect your limitations. For some elderly people, it may be a good idea to have someone around, at least when starting out.