Below are some health and fitness sites focused on older adults that you may find helpful.
Lifelong Fitness Alliance
http://www.50plus.org/
American Geriatrics Society
http://www.americangeriatrics.org/
American Diabetes Association
http://www.diabetes.org/
American Health Care Association
http://www.ahcancal.org/
American Heart Association
http://www.americanheart.org/
American Parkinson Disease Association
http://www.apdaparkinson.com/
National Arthritis Foundation
http://www.arthritis.org/
National Alzheimer's Association
http://www.alz.org/
National Senior Health & Fitness Day
http://www.fitnessday.com/