Retirement is traditionally seen as a time to rest and relax after a long life's career.  Undoubtedly, having the free time to take it easy is an important part of the retirement equation, but there's nothing that says your retirement has to be completely sedentary.  In fact, the more active you stay in your retirement years, the healthier and happier you'll be.  Retirement should be a time when you stop working, not a time when you stop having fun.

Many retirement communities offer activities designed to keep retirees physically fit, from exercise programs to walks to other low-impact activities.  Depending on your own health concerns and mobility, however, there's no reason you can't decide on your own fitness activities, and get out there and do something you enjoy.  Staying fit will keep you active and help maintain your physical health - regular exercise has been shown to ward off a number of diseases and conditions that can bedevil us as we age.

Activity doesn't just have to be physical, either.  Intellectual activity has been shown to help prevent Alzheimer's and other dementia disorders, so keep your mind active through mental pursuits like puzzles, reading, or even learning another language.  And social activity is also important, staying in touch with friends (or making new ones) will help your retirement years stay busy and full of life.  Take advantage of the fact that you're not tied down to a 9-to-5 job anymore, and live instead of work.