Michael Phelps has always talked about changing the sport of swimming. He certainly made it more exciting by collecting more Olympic medals than any other athlete in history. But where does the sport go now that its most visible star is retiring?

Swimming doesn’t have an established worldwide circuit, so the biggest chance its athletes have to be in the spotlight is at the Games. Some top competitors feel it’s time to capitalise on the window of opportunity Phelps’ success and the games created.

“It is hard for swimmers, just because it’s every four years and we only really get one time to shine,” Phelps’ American rival Ryan Lochte said.

“(A full-time circuit) is what we need if we want to make the sport bigger than what it is or what it was.”

In between Olympics and the biannual world championships, swimmers compete in a hodgepodge of international events such as the Pan Pacific championships, Asian Games, Pan American Games, Asian championships, European championships and Commonwealth Games.

“The calendar is so full that it’s impossible for coaches to understand how to accommodate the preparation, priorities and obligations of the athletes,” Cornel Marculescu, the executive director of swimming governing body FINA, had said.

The closest thing swimming has to an international regular season is the World Cup series — eight meets over six weeks starting in October with stops in Dubai, Doha, Stockholm, Moscow, Berlin, Beijing, Tokyo and Singapore.

The circuit pales in comparison to winter sport World Cups like the one in Alpine skiing, or even the Diamond League in athletics. It’s held in short-course venues that are half the size of Olympic pools, often failing to draw the top athletes.

During last year’s series, Phelps competed in just two World Cups, while Lochte has never been to one. Americans usually prefer to compete in USA Swimming’s Grand Prix series, but even in those events they’re not necessarily racing to win.

At a Grand Prix meet in Charlotte, North Carolina, in May, backstroker Nick Thoman swam with a beard, Phelps had a scruffy face and an unshaven body, while Lochte competed in a skimpy brief. Not exactly what you saw in London, where sleek, shaven swimmers competed in the latest compression racing suits.

Why so much disregard for these meets? Because swimming is a training-based sport, and for many countries the Olympics are all that really matters.

“Swimming is not cycling or tennis where you go from one circuit to another. It takes a long time to prepare for a very short moment and that’s the nature of the sport,” Australia head coach Leigh Nugent said.

More high-level competition could change the way athletes approach training. Many Olympic swimmers train non-stop for two, three or four years leading up to a games, with daily workouts of up to 10 miles (15 kilometers). That may turn out to be rewarding for the very best, but most of the nearly 1,000 swimmers who compete at an Olympics go home without a medal.

There’s also a worry that more racing won’t produce the routine record-breaking swims that an event like the Olympics does, because it’s impossible to train to reach that level of performance all the time.

“I say you just appreciate great racing. It doesn’t necessarily have to be a world record,” said American breaststroker Eric Shanteau, a cancer survivor who won a gold medal with the US 4x100-meter medley relay squad.

“It’s more about following the story of any one of us.

It’s pretty interesting to see how we train and how we race during those years, not just how we race at the Olympics.”

Sponsorship plays a role, too. Current prize money at World Cup meets is just $1,000 for race winners, $ 500 for second place and $250 for third. Overall points leaders for men and women over the course of the series win prizes of $100,000 each.

Cameron van der Burgh of South Africa, who set a world record to win the 100m breaststroke at these Games, suggested allowing swimmers to wear personal sponsors — even non-swimming brands — on their caps. That’s not allowed right now, but such sponsorship is common in other sports, such as skiing, where athletes sport logos on their headgear.

Total prize money for the US-based Grand Prix series this year was about $20,000, although USA Swimming plans to multiply that by five or six times for the next edition.