A new generation of seniors is redefining what it means to be 'old.' Jim Arrington lives in Southern California, and became the world's oldest male bodybuilder in his mid-80s. "I'll keep going as long as I possibly can," he says. When Ida Keeling hit the century mark, she became the oldest woman to run the 100-meter dash at Philadelphia's Penn Relays, and celebrated the feat by doing push-ups! And Robert Marchand cycled 14 miles in an hour at 105 years old.