I was watching the Olympics and XC skiing caught my eye. I was wondering what type of aerobic engine these guys have. Many elite runners that cant quite make it on the world stage become elite tri athletes, take Alex Yee for example. XC skiing seems like a very endurance based sport. Are the technical aspects of Cross Country Skiing that difficult to learn, or am I missing something? Seems to me that a good runner that puts in the time could become an elite Cross Country Skier, but then again I know nothing about the sport. Curious on what people more knowledgeable then me feel about this.