Replying to Why should skiing be considered an extreme sport? Research paper.

Okay so I am doing a research paper for English class and I decided to do it on Why skiing should be/is considered an extreme sport. We have to take a stance and present facts and sources to back up our stance. The stance I am taking is that Skiing should be considered an extreme sport but I need some help on where to start looking for things to prove that it is an extreme sport that arn't completely opinion based.

I am going to compare it to other extreme sports in terms of risk and skill to do certain aspects of the sport.

So what I am asking is if you guys could give me your opinions on why skiing should be considered an extreme sport and also to help me find some less opinion bases material to base some of my points off of.

All help would be greatly appreciated since I have to write 5 pages by Friday.

Thanks! and if you have any questions just post them in here or send me a PM or something