The battle of the sexes has hit the pool.

The opening meet of the World Cup in Dubai on Tuesday will feature 4x50-metre mixed relays for the first time, a medley race that will be followed by 4x50 mixed freestyle relay on Wednesday. Teams will be made up of two men and two women, and it is up to them to decide the order — so, for instance, a woman could race against a man on the anchor leg.

The initiative will be used at all eight World Cup meets. Swimming's governing body, FINA, has said the event could be introduced at the short-course world championships in Istanbul in December and one day become an Olympic event. The mixed relays will also feature in November at the European short-course championships in Chartres, France.

"You know, it's really important for every discipline, every sport, to improve. To look forward to develop further," FINA Executive Director Cornel Marculescu said Monday. "We will test it in the World Cup and see how this is going, and will probably introduce at the World Championship if results are acceptable for swimmers and coaches."

The lineups for the relay were not available Monday, but the top swimmers competing include 100 breaststroke Olympic champion Cameron van der Burgh and multiple Olympic medallist Therese Alshammar. They both welcomed the new event as a chance to further raise the profile of swimming, which often suffers a significant drop in interest between Olympics.

Amazing performance

The move comes in the wake of Chinese star Ye Shiwen's amazing performance at the 2012 London Games, in which her last lap in winning the women's 400-metre individual medley was a split-second faster than American champion Ryan Lochte posted in the last 50 of the men's race.

"I think it will be interesting," Van der Burgh said. "When we bring in these kinds of relays, it will be extremely exciting for the first couple of years. No one knows what will happen — who are the favourites? How it will work? Who they will choose? I'm all for making sport bigger."

Austrian swimmer Markus Rogan was less enthusiastic when asked earlier this year.

"That's for the next generation," he said. "I hope people figure out very quickly that there's one clear formula to swim the fastest, which is to make the girls swim the fastest strokes. The guys have to swim breaststroke. But I'm sure some nations will try to split it a different way."

Critics have complained that it only adds another event to an already crowded schedule and that there are already plenty of big names in the sport to attract fans.

"Personally, I don't support it. I don't think we need innovation at all costs," European Swimming Federation President Paolo Barelli said. "We've already got a full program over eight days (at major competitions), with great personalities — men and women."

This won't be the first time that mixed relays have taken place.

There was one at the 2007 Duel in the Pool after the worlds in Melbourne, in which Libby Lenton (now named Trickett) set a world record when racing against Michael Phelps. The record was not recognized.

Mixed relay

There was also a mixed relay at the inaugural 2010 Youth Olympics in Singapore, which generally received positive reviews.

Van der Burgh and Alshammar have both raced in them in the past. Alshammar said mixed relays were commonplace in her native Sweden, while Van der Burgh took part last year in one at the Salnikov Cup in Russia.

"The race went off and it was great to watch," Van der Burgh said. "To watch the last 50 metres was extremely exciting, seeing some of the girls out front and the men hunting them down. For me, the spectator value was extremely high because it was something that hadn't been done before."

Both swimmers said they would treat the mixed relay like any other race, concentrating on their own performance and not worrying whether they were up against a man or a woman.

"It's not like rugby where we have to be careful about breaking a girl's bones," Van der Burgh said. "When you are swimming for the team, you have your own lane and you swim your own race like normal. When I'm at the Olympic Games, I'm not thinking about other people."

Alshammar conceded that racing against a man would have its benefits.

"For women, it would be an advantage to race a guy because you can always chase someone, so that would be a good incentive," she said.