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