London: Misty May-Treanor and Kerri Walsh will attempt to win a third successive Olympic beach volleyball gold medal, but they face a double battle against age and rising Chinese hopes if they are to prevail.

In Beijing four years ago, the American pair defended the title they had won in Athens in 2004.

They also put together a winning run of 112 matches before their lives and priorities changed.

May-Treanor, now 34, damaged her Achilles while taking part in the American TV show Dancing With Stars and missed the 2011 season while Walsh, a year younger, left the sport to have two children.

They have recently reformed for the London Games, but are only ranked three in the world behind gold medal favourites Juliana Silva and Larissa Franca of Brazil and second-ranked Chinese pair, Zhang Xi and Xue Chen.

But the pair are desperate for a rematch with the Brazilians.

May-Treanor and Walsh claim the Brazilians indulged in over-the-top celebrations when they beat the Americans at the 2011 world championships.

It was their first loss at a major in 10 years.

In recent weeks, the top three pairs have been dominating the world tour events.

The Chinese team of Zhang and Xue showed they are peaking at the right time by taking a third title at the Moscow leg of the championship, over-powering their American rivals.

The Moscow event saw world champions Franca and Silva have to be content with bronze.

“They earned it. We did not attack them enough. I know we can play a lot better and that on the other hand makes me happy,” said Walsh.

The Chinese are in top form, also winning gold in Brasilia and Shanghai and bronze in Sanya.

Zhang said: “We matured a lot this winter. Last year we got carried away whenever it came down to it, we did not have peace inside. This is better now. And we trained a lot on being more aggressive in attacking.”

But the Chinese are not making predictions for London.

“We try not to think about that yet, we take it step-by-step,” said Xue.

The Olympic beach volleyball tournament will be played in a specially created stadium at Horse Guards Parade near Buckingham Palace.

And in an effort to encourage more involvement in the sport, competitors will be allowed to wear shorts and sleeved tops if they consider trademark skimpy bikinis to be too revealing for more conservative nations.

“I think it is the right decision because it will allow more women to join the sport,” said Malaysian youth volleyball coach, Sara Daret.

“The bikini is still the best thing to wear because it gives freedom of movement that shorts and sleeves don’t, but it should not be the decision of a committee for what women wear.”

In the men’s event, American world champions Phil Dalhausser and Todd Rogers will be defending the title they won in Beijing.

But the top-ranked pair are Brazil’s world champions Alison Cerutti and Emanuel Rego who won in Moscow.

“The main priority in this Olympic year is to be on every podium,” said Rego, a gold medallist in Athens in 2004.

“We improve step-by-step, but this is a big step because Moscow is a grand slam title.”