Blodslitet is an international ultra-long orienteering race held in Fredrikstad, Østfold, each October, concluding the season for Fredrikstad Skiklubb. This is not a typical trail race; participants use a map to navigate forest terrain. The event offers courses ranging from short distances for youth and amateurs to long elite distances, with options from 5 km up to 50 km. Blodslitet also hosts Norway’s ultra-long championship, NM ultralang.
The race arena is situated near Gillingsrød, with forest terrain prepared for orienteering, not just marked paths. Multiple classes begin simultaneously, creating a competitive atmosphere from the initial controls. Children and youth have their own program with mass starts and courses slightly longer than typical. Elite runners, club orienteers, recreational participants, and younger competitors share the same race day. Live results and GPS tracking allow spectators to monitor the race as it unfolds in the woods.