It's fast, furious and threatens to present the Sochi Winter Olympics with its first major headache as the hunt for snowboarding gold is launched at the Rosa Khutor Extreme Park.

More than 240 athletes from 31 nations and regions were due to fly down the troubled track from Thursday, but that number has already been reduced by one after Norway's gold medal favorite in slopestyle, Torstein Horgmo, crashed in training and sustained a broken collarbone.

Fellow athletes complained aspects of the course were too dangerous, held an emergency meeting and forced officials into a rapid tweak of the most challenging aspects of the run.

Even American double Olympic champion Shaun White said the daunting slopestyle course where competitors tackle various forms of obstacles - rails, quarterpipes, and jumps - is intimidating.

But White, the 27-year-old X Games pioneer, who has undergone a succession of knee and ankle surgeries, said the spectacular sport is full of dangers.

"It's intimidating. You know any time you show up to a course you have to learn the speed, the distance from the jumps and what the rails are like. It's been a challenge," said White.

"Any time you step out on a course there's a certain amount of danger, there's a certain element of risk.

"Maybe this course might have a little bit more than others, but we're trying to figure it out.

"We're trying to get through the course, be safe and have a great Olympics."

White, the halfpipe champion in Turin in 2006 and Vancouver in 2010, is looking for a record third gold in the discipline as well as hoping to capture the inaugural slopestyle title.

The snowboard competition opens on Thursday.

In slopestyle, the athletes navigate their way through a series of rails and other features at the top of the course before moving on to three progressively bigger jumps.

Masters of the "triple cork" - three off-axis flips combined with three or four full spins - are the likes of White, along with Canadian trio Mark McMorris, Maxence Parrot and Sebastien Toutant as well as Staale Sandbech of Norway.

The leading women will be performing double flips with medal favorites including Norway's Silje Norendal, Jamie Anderson of the US and Cheryl Maas from the Netherlands.

The halfpipe will see White bidding for a third successive gold, but he faces stiff competition from 15-year-old Japanese sensation Ayumu Hirano.

On the women's side, reigning champion Torah Bright, who is also competing in slopestyle and snowboard cross, faces American duo Kelly Clark and Arielle Gold.

Snowboard cross, which features four riders racing down a winding mountain course, gives American Lindsey Jacobellis, who famously fell to the ground with the gold in her grasp at the 2006 Turin Games, a final chance.