Sixty years ago, 17-year-old Randy Gardner broke a Guinness world record by staying awake for 11 consecutive days. His experiment is one of the most well-documented cases of sleep deprivation.
Paleoanthropologist Daniel Lieberman says the concept of "getting exercise" is relatively new. His new book, Exercised, examines why we run, lift and walk for a workout when our ancestors didn't.
CNN's chief medical correspondent says it's never too late to develop new brain pathways. Even small changes, like switching up the hand you use to hold your fork, can help optimize brain health.
