The 26-year old says that while he has loved his time in the sport, he doesn’t “feel a burning passion to feel the best that he can be.”
Pieroni made his first Olympic team in 2016, where he swam a prelims leg of the American 400 free relay that won a gold medal. He split 48.39 on the prelims relay’s 3rd leg along with Jimmy Feigen, Ryan Held, and Anthony Ervin. Of that group, Held advanced to finals to swim with Nathan Adrian, Michael Phelps, and Caeleb Dressel as the group cleared France by half-a-second for the gold medal.
At the Tokyo Games, Pieroni qualified to swim on all three American men’s relays. In the 400 free relay, a 47.71 split in prelims was enough for him to earn a reswim in finals, where he split 47.58. The Americans this time won gold by over a second, ahead of Italy, in 3:08.97.
Pieroni also split 48.25 on the anchor leg of a 400 medley relay, with the finals team winning gold to get him more hardware.
He also swam the anchor leg of the prelims 800 free relay, splitting 1:46.21. The finals relay wound up pacing 4th, off the podium. If Pieroni had swum finals in place of his training partner Zach Apple, and repeated his split, the Americans would have won silver, hypothetically.
Pieroni pulled out of the USA Swimming International Team Trials earlier this year because of a knee injury that required him to have surgery in March. He was forced to pull out of the ISL season in 2021 after injuring the knee while lifting weights. His last race was at the FINA Swimming World Cup in Doha, Qatar in October.
Pieroni retires with 16 major international senior championship medals. That includes four long course World Championship gold medals and four short course World Championship gold medals. His lone international podium individually was the 2018 World Short Course Championship in the 200 free.
He trained collegiately at Indiana, where in 2018 he became the first swimmer to ever break 1:30 in the 200 yard free. He swam 1:29.63 on the leadoff leg of the 800 free relay and opened the flood gates to the world of 1:29s: since then, three other men have done so (Dean Farris, Kieran Smith, and Townley Haas).
In his collegiate career, he earned 19 All-American honors, including the maximum seven as a senior. His highest individual NCAA finishes came in that senior season, where he was 2nd in the 100 free, 2nd in the 200 free, and 4th in the 50 free. He also placed 2nd in the 200 free as a junior in 2017.
In high school, Pieroni was a three-time Indiana High School State Champion in the 100 free and two-time Indiana High School State Champion in the 200 IM. He led Chesterton High to back-to-back state titles and swam on National High School Record-breaking 200 medley and 400 free relays.
As a prep swimmer, he also won a bronze medal on the American 800 free relay at the 2013 World Junior Championships.