Ski orienteering (SkiO) is a cross-country skiing endurance winter racing sport and one of the four orienteering disciplines recognized by the IOF. A successful ski orienteer combines high physical endurance, strength and excellent technical skiing skills with the ability to navigate and make the best route choices while skiing at a high speed.
Standard orienteering maps are used, but with special green overprinting of trails and tracks to indicate their navigability in snow; other symbols indicate whether any roads are snow-covered or clear. Navigation tactics is similar to mountain bike orienteering. Standard skate-skiing equipment is used, along with a map holder attached to the chest.[1] Compared to cross-country skiing, upper body strength is more important because of double poling needed along narrow snow trails.