All eyes on Biles at world gymnastics in Qatar

More than 500 gymnasts descend on Qatar this week for the Artistic Gymnastics World Championships, but most eyes will be on the sport's biggest star, the USA's Simone Biles.

The quadruple Olympic gold medallist will make her return to frontline international competition after taking a year off following her triumphant showing in Rio in 2016.

Her self-enforced absence from the sport -- she returned to competition in July -- has only served to increase expectation for the 10-day championships, the first ever to be held in the Middle East.

Biles, 21, will become the first woman in history to win four world all-around titles if she takes gold in that discipline in Doha.

Her main competition is likely to come from teenage compatriot Morgan Hurd, the 2017 champion.

Biles could also take gold in the vault, floor exercise and beam competitions. She is a member of an exceptionally strong US team looking for its fourth consecutive straight world title, but their preparations have been anything but smooth.

Since Biles performed in the 2016 Olympics, it has been a tumultuous time for US gymnastics.

In July 2017, former team doctor Larry Nassar was sentenced to up to 175 years in prison on charges of sexual assault. In January this year, Biles revealed herself to be one of his victims.

In the fallout, US gymnastics chief executive Kerry Perry resigned because of her handling of the scandal.

And just this month, interim CEO Mary Bono resigned after just five error-strewn days in charge after posting a critical tweet alluding to Nike and its support for NFL star Colin Kaepernick, who triggered a political firestorm after kneeling during the US national anthem to protest racial injustice.

Biles was hugely critical of Bono, taking to Twitter to say "it's not like we needed a smarter usa gymnastics president or any sponsors or anything".

Doha presents the US with a chance to draw a line under the chaos which has engulfed the team in recent years.

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