Michael Phelps wins 23rd historic gold

And, owning a record 23 Olympic gold medals after his final race at Rio 2016 ended with victory in Saturday's 4x100-meter medley relay, he has. Swimming is richer because of him, and will be poorer without him, CNN reports.

People talk about the Phelps legacy, with some arguing his greatest contribution is yet to be realized with the list of pool performers he has inspired.

But the current legacy is illustrated in a decade-old photograph of a delighted nine-year-old Katie Ledecky with Phelps -- the American teenager is proving to be the dominant female swimmer of these Rio 2016 Olympic Games.

Similarly it was captured on Friday in Rio as Joseph Schooling, who himself had been inspired by the Phelps phenomenon and was photographed with him as a youngster, stood disbelieving on the top step of the 100-meter butterfly podium above the US star.

"We've all seen the photo of Katie and I when she was nine, and the photo of Joe and I," Phelps told reporters after the race. "I wanted to change the sport of swimming. That's what I wanted to do. With the people in the sport now, I think you're seeing it."

It is no idle boast. After each of his triumphant Olympic swimming meets, USA Swimming membership soared.

In the year post-Athens, it rose 7%, after Beijing there was an 11% increase, while what appeared to be his Games swansong in London sparked a 13% rise in those taking up the sport stateside.

A further spike is anticipated by USA Swimming, whose latest figures show that when Phelps made his debut for the team, just 38% of their members were male; that figure is up to 44% and rising.

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