The Kahler Asten Trail Marathon, designed as a circular course, starts at the Schützenhalle and initially leads the riders over the Herhagen into the valley of Nordenau. This is followed by a significant climb that crosses the Astenberg ski area. After various downhill sections, there is another challenging ascent that leads over natural paths to Wesenberg. A pronounced trail descent, which marks the lowest point of the route, is followed by an extended ascent that almost reaches the Astenberg. A longer downhill section, interrupted by a charming trail section, then offers the opportunity for physical recuperation before the final, steep climb, the final section of which is asphalted. From this point onwards, the route runs over undulating, ascending terrain. An extended downhill section, which integrates technical passages, leads down to Obersorpe. A subsequent flat section allows for a regeneration phase before heading for the next elevation. After a longer, moderate descent, the route leads into a steep singletrail that leads to Oberkirchen. The direction of travel now changes to Lengenbeck, where, after another ascent, an extended descent offers a chance to recover. A final, steep ascent demands substantial reserves of strength before the finish area.