1. Use it or lose it.
As you age, it's important to pay attention to cognitive function and to make the effort to stay mentally alert and stimulated. That means keeping your brain busy. Read, do crossword puzzles, socialize, try new hobbies. (Maybe it's finally time to learn French!)
2. Strength training: It's never too late to start.
At 65, you may think the heaviest thing you should lift is the remote. Not true. We inevitably lose bone mass and flexibility with age. But regular strength training (with an OK from your doctor, of course) can keep you on your toes, prevent muscles from wasting away, and help you avoid falls and other accidents. The American Association of Retired Persons reports that studies have shown that men in their 60s and 70s who strength train regularly have muscles that look and perform as well as inactive men in their 20s and 30s.
3. There's still time to quit!
If you've been trying for years to kick a heart-unhealthy habit such as smoking or drinking to excess, don't figure that the damage has already been done. It has -- but you can repair or avoid some of it if you quit now. Studies have shown that people who stop smoking at age 65 add almost two years to their lives, cutting their risk of heart disease and lung cancer.
4. Don't forget key screening tests.
You'll probably hear a lot about flu shots, but don't forget the pneumonia shot, which you should get at age 65. Stay in touch with your doctor to keep up with regular cholesterol, hypertension, and diabetes testing, and have a colonoscopy every 10 years.