I've worked with thousands of people with difficult physical limitations, but some of them have had the most glorious spirit and outlook on life. Anyone who has a physical limitation may have to work harder to age well and stay healthy, but your elder must not let his or her spirit wane or look at himself or herself as a victim.
Elders often know their own bodies, and what they need. Having a membership to a health club isn't what gets you healthy - you actually have to do the exercise. Whether your elder does an exercise regime on his or her own or follows a DVD or TV workout program, it's crucial that your elder moves around on a regular basis to stay energized and firm and alive.
Before starting any exercise program, consult your elder's primary physician for a baseline assessment of the ideal level of physical activity. Another hint: keep it enjoyable or your elder won't stick with it for very long. The activity must be something that becomes a fun part of the daily routine, whether it's walking, biking, or practicing yoga or tai chi. I also recommend getting a small dose of sunshine every day, and getting adequate sleep every night.
Another proactive healthy aging tactic is to eat right and hydrate - and that takes planning and effort. Suggest that your elder make a list of preferred foods (that are also healthy) and then go buy them. Make sure fresh fruits and vegetables, as well as lean sources of protein are in the home at all times, and don't let unhealthy food through the front door (you know what foods I'm talking about!). This will eliminate the temptation to eat junk food, at least while at home.
To age successfully, it also helps to stay closely connected to family, friends, and to some sort of spiritual life, if you so desire. Finding a place to volunteer your time and expertise also helps. I encourage the pursuit of anything that makes you feel like you're part of your community and the universe at large. And remember to look for the fun in all of your activities. Keep your mind open to positive experiences and they will unfold in your life.
Finally, it's important to settle old grudges and hurts. Wipe your emotional slate clean every day before you go to bed. Sometimes this requires an email, a phone call, or just coming to terms with the conflict in your own mind. Be grateful for being alive so that you can live life to the fullest.