Bryce Harper becomes Katie Ledecky's medal boy as she throws out first pitch

One by one, swimmer Katie Ledecky handed her Olympic medals to Bryce Harper. Four gold medals and one silver from the Rio Olympics sat in the hands of the reigning National League MVP.

As the Nationals star outfielder admired the medals of the Olympic champion and held her hat, Ledecky threw the ceremonial first pitch to reliever Shawn Kelley before the Baltimore Orioles beat Washington 10-8 Wednesday night.

"I've swum in front of 14,000 people," Ledecky said of the pitch. "Once the ball leaves the hand, you can't really control it."

Ledecky, a native of nearby Bethesda, Maryland, has thrown out the first pitch at Nationals Park before. That was in 2012 after she won the 800-metre freestyle at the London Olympics as a 15-year-old.

"I think I've gotten stronger and a lot's happened in four years," she said. "I've been to a couple world championships, more international meets, another Olympics, I've gone through high school, I'm heading out to college. Looking back four years ago, a lot has changed since then."

Ledecky has just become more dominant.

She tied as the most decorated U.S. female athlete in Rio along with gymnast Simone Biles and just short of Michael Phelps for the most among Americans. Before Ledecky's first pitch, a tribute played on the video board, featuring a clip of her world record-shattering victory in the 800-meter freestyle performance in Rio when she won by more than 11 seconds.

The 19-year-old met several Nationals before the game, including Harper, whom she called one of her favourites. They didn't give her any tips on the first pitch, which she said she practiced plenty Tuesday, but they were curious about her five medals.

"They all wanted to see how heavy they were and things like that," Ledecky said. "They are pretty heavy. It was kind of a different feeling for me to have them be a fan of me when I've been a huge fan of theirs for a couple years."

Ledecky got a warm reception on the field 20 minutes before the start of the game but a rousing standing ovation when she was shown on the video board before the fifth inning. Fans cheered and broke out in chants of "U-S-A! U-S-A!"

She said her accomplishments in Rio are "slowly but surely" sinking in, only days after the closing ceremony.

"I expect it'll sink in as we move forward the next couple weeks," Ledecky said. "Once I get back in the pool and start working toward my next goals, I know you just kind of have to put everything you've done behind you and start working toward the next thing."

For now, the next thing is college. Ledecky will be a freshman at Stanford in the fall and plans to take some time off before starting school.

Before she finds out who her roommate is, Ledecky's mind is already on the Tokyo Olympics in 2020.

"It'll probably be the longest break I'll take in the next four years," she said. "It's just nice to be out of the water a little bit and get recharged for the next four years."