We're always hearing that 60 is the new 40 and 40 is the new 20... is it really true that age is just a number?
Americans are living longer than ever before, and many say they feel younger than their age.
Genetics certainly play a role in how we age, but 70 to 80 percent of our vitality depends on personal choices, like how we eat and exercise, according to Health.com. How old are you really? Tell TODAY how old you feel in this survey, and take the full "real age" test at Health.com.