Phelps keeping coy about possible comeback plans

When Michael Phelps walked away from swimming after the London Olympics, he was adamant that his career was over.

Now it sounds like he's not so sure.

While saying he's never been happier - and that he certainly doesn't miss the grind of what it took to become the most successful athlete in Olympic history - Phelps left the door open to change his mind before the 2016 Rio Games.