Maebashii, Gunma, Japan · Sunday, September 27, 2026

Fixed Distance 100K

Mount Akagi 100 Ultra Marathon

24 days to go

100 km Distance

not publishedn/a Climbing

5.0 est Grit · Challenging

Calculated from 100 km alone — the organiser has not published an elevation profile. Read 5.0 as a floor, not a verdict.

What the course asks

Time limit 16 hours 9:36 min/km average. Comfortable. Room to walk the climbs and stop at aid. Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. About average for a 100K. Measured against 203 races of the same distance. Cut-off calculator →

Field size ~172 Mid-sized. Company early, well spread out by halfway.

DUV results for the 2025 edition (50km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, September

Daylight 12 h 01 m of light

The Aid Station

Course-specific beta from the community

👟 gear

With trail terrain, choose a shoe with moderate cushioning for optimal performance.

By UltraHub Expert

🥤 nutrition

For 100km+ efforts, prioritize real food at aid stations to prevent palate fatigue.

By UltraHub Expert

Gear for this race

Chosen for 100 km of trail.

Trail Running Shoes 100 km of trail — cushioning that is still there in the last quarter.
Race Nutrition Past 100 km the palate quits before the legs do — carry more than one flavour.
Hydration Vests Flask capacity for 100 km, without the bounce.
Headlamps A 16 h limit puts you out there after dark.
Accessories Chafe and blisters end more 100 km races than fitness does.