Updated

President Barack Obama congratulated the five members of the U.S. women's gymnastics team Wednesday on their Olympic victory — and he had some questions about just how they managed to pull off their gold medal performances.

"I told these young ladies as I was congratulating them, how do you not bust your head every time you're on that little balance beam?" Obama said. "I couldn't walk across that balance beam."

Obama telephoned the gymnastics team from Air Force One as he traveled from Washington to Ohio for campaign events.

The president has also been watching some Olympic swimming. While traveling in Ohio Wednesday, he called American swimmer Michael Phelps to congratulate him on becoming the most decorated Olympic athlete.

Phelps picked up his 19th Olympic medal — a gold — in a men's relay Tuesday.

The White House said the president told Phelps he was "the greatest Olympian ever" and that the country "couldn't be prouder."

Campaigning in a political battleground state, Obama singled out Olympians from Ohio. And he said the "wonderful thing about the Olympics is that it reminds us that for all our differences, when it comes down to our country, we are Americans first."