Ultra Running Hub Chiang Dao, Thailand · Wednesday, December 23, 2026
Fixed Distance 50K
CORE X50 Ultra Trail
98 days away
50 km Distance
not publishedn/a Climbing
2.5 est Grit · Entry level
Calculated from 50 km alone — the organiser has not published an elevation profile. Read 2.5 as a floor, not a verdict.
What the course asks
Time limit 15 hours
18:00 min/km average. Generous. Walkable throughout for most of the field. Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. Among the most forgiving 50K cut-offs we track. Measured against 1007 races of the same distance. Cut-off calculator →
Field size ~18 Tiny. You will run alone for most of it.
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, December
Daytime high 23°C
Night low 13°C
Rainfall Dry — rain unlikely
Daylight 10 h 58 m of light
Regional 2001-2020 average for December — NASA POWER, grid elevation 911 m. Not a forecast.
The Aid Station
Course-specific beta from the community
With trail terrain, choose a shoe with moderate cushioning for optimal performance.
Gear for this race
Chosen for 50 km of trail.
- Trail Running Shoes50 km of trail — cushioning that is still there in the last quarter.
- Race Nutrition50 km of self-supported fuelling between aid stations.
- Hydration VestsFlask capacity for 50 km, without the bounce.
- HeadlampsA 15 h limit puts you out there after dark.
- GPS WatchesBattery life first — a 50 km day outlasts most full-GPS modes.
Similar races
Other 50K trail ultras, closest in distance first.