SYDNEY -- Australian gold medalist Mack Horton, who had an intense rivalry with China's Sun Yang, announced his retirement Sunday from international swimming.
Horton, 27, won gold in the 400-meter freestyle at the Rio Olympics in 2016, but six months out from the Paris Games, he says he no longer has the necessary motivation to continue.
"I dearly wanted to swim in Paris but the hunger wasn't there," Horton said in a Swimming Australia statement released on Sunday. "I always want to give my all and I am not someone who just wants to make up the numbers, so this is the right time to step away.
"I am so grateful for my time in swimming and in regard to legacy, I hope my teammates and the sport think that I was able to help them and the sport in some way."
Horton, perhaps, is better known for his advocacy of clean sport and particularly his strong views on rival Sun Yang whom he branded a "drug cheat" at the Rio Games.
The Australian then refused to stand on the podium next to Sun at Gwangju, South Korea in 2019 after the Chinese swimmer won his fourth consecutive 400-meter freestyle world championship gold medal. Horton placed second, taking silver in a reversal of their Olympic final in 2016 when the Australian won gold.
Sun was banned from international swimming for four years, three months by the Court of Arbitration for Sport in 2021 for refusing to give a sample and tampering with a doping control.
Horton won a bronze medal as a prelim swimmer in the 4x200-meter freestyle at the Tokyo Games, after failing to qualify for the Australian team to defend his 400-meter gold from Rio.
He also won seven world championship medals, four Pan Pacific Championship medals, and eight Commonwealth Games medals, including four gold.