Missy Franklin 'Disappointed' by Her Olympic Performance

"I feel like I have so much left so learn from this sport," she said.

But Rio has been a different story for the young swimmer, as she failed to qualify for the 200 meter freestyle final -- an upset that left her heartbroken.

"But, you know, that positivity just comes from knowing that I did the best that I possibly could and it just wasn't my week," Franklin said. "It's heartbreaking that all the hard work and sacrifices I made just didn't show up, but I know that they will eventually and I think I'm going to be so much stronger after this experience."

Franklin vows to return to the next Summer Olympics stronger than ever as we look ahead to Tokyo 2020.

"I feel like I have so much left to learn from this sport, so much left to give to it, so I would love to be [in] 2020," she said.

Regardless of her personal disappointments, Franklin said she's proud of Team USA, which dominated this year's Olympics, winning 33 medals including 16 gold.