KAT100 by UTMB
KAT100 by UTMB – Marathon Trail
Fieberbrunn
Race guide
Updated 19 July 2026
The KAT100 by UTMB Marathon Trail is the 51 km loop of the KAT100 by UTMB, starting and finishing in Fieberbrunn in the Austrian Tirol. Across its 50.7 km it climbs 3,119 m and reaches the highest point of any KAT distance at 2,085 m, making it a short-format race with a genuinely mountainous ratio of vertical to distance. Run as a loop from 783 m in Fieberbrunn, the Marathon Trail delivers its biggest climb early, then works through a series of alpine checkpoints before returning to town. With cut-offs beginning at Wildseeloderhaus (Saturday 10:00) and a final gate at Fieberbrunn of Saturday 19:00, it is compact enough to race hard yet steep enough to punish anyone who mistakes the distance for an easy day.
The Course: A Steep 51 km Fieberbrunn Loop
The Marathon Trail is a 50.7 km loop with 3,119 m of ascent, beginning and ending at 783 m in Fieberbrunn. Almost immediately it climbs to Wildseeloderhaus at 1,852 m by 10.1 km — over 1,000 m of gain in the opening section — establishing the high point of the day near 2,085 m. From there the route descends to Lärchfilzhochalm at 1,378 m (16.9 km) and continues down to Parkplatz Herrgottbrücke at 1,055 m (27.7 km). The second half rebuilds height, climbing to Karscherm at 1,686 m (34.2 km) before dropping back to Lärchfilzhochalm at 1,370 m (43.2 km) and making the final descent into Fieberbrunn at 50.7 km. It is a two-climb course in essence — the big early haul to Wildseeloderhaus and the substantial mid-race ascent to Karscherm — bridged by technical alpine descents that give the legs little respite.
Where the Race Is Decided
The opening climb to Wildseeloderhaus is the defining feature of the Marathon Trail. Gaining more than 1,000 m in just over 10 km straight from the start, it sets up the day's high point around 2,085 m and sorts the field fast. Runners who sprint this ascent to chase position often pay for it on the second climb; those who hike it strongly and eat early tend to run the back half far better. The second decisive point is the climb from Herrgottbrücke (1,055 m) up to Karscherm at 1,686 m between 27.7 and 34.2 km — a ~630 m ascent that comes when the early effort is catching up with you. Manage it steadily and the remaining descent to Lärchfilzhochalm and the run-in to Fieberbrunn become a chance to make time. The descents themselves, off Wildseeloderhaus and again toward the finish, are long enough that quad fatigue is a real risk, so controlled, efficient downhill running matters as much as the climbing here.
Pacing and Fueling It
The Marathon Trail carries cut-offs at every checkpoint: Wildseeloderhaus at 10.1 km (Sat 10:00), Lärchfilzhochalm at 16.9 km (Sat 11:30), Herrgottbrücke at 27.7 km (Sat 13:50), Karscherm at 34.2 km (Sat 15:50), Lärchfilzhochalm again at 43.2 km (Sat 18:00) and the Fieberbrunn finish at 19:00. The gates are spaced tightly enough that a slow, over-cautious first climb can leave you fighting the clock later, so aim to bank a modest buffer on the Wildseeloderhaus ascent without redlining. Because this is a shorter mountain race, aid stations come relatively frequently at the checkpoints, but the climbs between them are demanding — plan to fuel steadily rather than waiting for the tops. Drink and take calories on the descents to Herrgottbrücke and Lärchfilzhochalm when your effort eases, so you reach the Karscherm climb well supplied. Given the sub-2,100 m high point and the exposure early on, carry a light layer even for a fast day; conditions at Wildseeloderhaus can be markedly cooler than in the Fieberbrunn valley.
Conditions to Expect
With its high point at 2,085 m, the Marathon Trail is the most altitude-exposed of the shorter KAT distances despite its length. The opening climb quickly lifts you from the 783 m valley to the tops around Wildseeloderhaus, where wind and cooler temperatures are common even when the start feels warm. The high ground near the day's summit and the Karscherm climb are the sections most likely to be exposed to changeable alpine weather. Most runners will complete the loop in daylight given the Saturday morning start and 19:00 finish cut-off, but mountain weather in the Kitzbühel Alps can turn quickly, so a packable wind or waterproof layer is a sensible insurance policy. The main physical challenge is the concentration of vertical — 3,119 m in barely 51 km — combined with technical descending. Runners who climb within themselves early, protect their quads on the long downhills and keep fueling through the frequent checkpoints are best placed to finish strong in Fieberbrunn.
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Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-17) · official source
0 km · 783 m · —
10.1 km · 1852 m · Sat 10:00
16.9 km · 1378 m · Sat 11:30
27.7 km · 1055 m · Sat 13:50
34.2 km · 1686 m · Sat 15:50
43.2 km · 1370 m · Sat 18:00
50.7 km · 783 m · Sat 19:00
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