Skiing - cross-country, over 7.9 mph (racing)

This activity burns approximately 921 calories per hour

Competing in cross-country ski races represents one of the most physically demanding activities known to the sporting world. Cross-country skiing competitors expend an inordinate amount of energy as they fly up long, steep hills and jockey for position over the length of the race course. World-class skiers can easily expend thousands of calories during an event lasting more than an hour.