Heavy running alone will give muscular legs and thighs, but the upper body may look almost wasted. Exercise promotes strength, flexibility, and endurance-staving off feebleness in old age. Get regular exams and screening tests from your own physician. A multivitamin a day, plus 250 milligrams of vitamin C, seems reasonable. The new daily recommendation for vitamin C has been raised from 60 to 120 milligrams.
Some physicians recommend adding vitamin E and selenium.
Don't plan to retire completely. Especially, don't retire both your body and mind. A few part-time hours or volunteer work may add further pleasure and meaning to your life. Put more money aside for your later years. You are probably going to live 20-40 years past the usual age of retirement.