Chiang Mai, Thailand · Saturday, October 3, 2026

Fixed Distance 100K

CNX 100K Ultra Marathon

17 days to go

100 km Distance

872 m Climbing

6.3 Grit · Hardcore

18.7904° N, 98.9847° E© OpenFreeMap © OpenMapTiles Data from OpenStreetMap

What the course asks

Climbing rate 9 m / km Fast & Flat. This course is relatively flat and fast. Ideal for PB attempts.

Time limit 18 hours 10:48 min/km average. Generous. Walkable throughout for most of the field. About average for a 100K. Measured against 208 races of the same distance. Cut-off calculator →

Field size ~385 Large. Rarely out of sight of another runner.

DUV results for the 2025 edition (100km) — finishers only. Starters are not published, so the field was at least this big and no finish rate can be given.

Typical conditions, October

Daytime high 26°C

Night low 19°C

Rainfall Showers likely

Daylight 11 h 57 m of light

Regional 2001-2020 average for October — NASA POWER, grid elevation 759 m. Not a forecast.

The Aid Station

Course-specific beta from the community

⛰️ terrain

This is a fast & flat course. Expect fast, runnable sections where rhythm is key.

By UltraHub Expert

👟 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 with 872 m of ascent.

Trail Running Shoes100 km of trail — cushioning that is still there in the last quarter.
Race NutritionPast 100 km the palate quits before the legs do — carry more than one flavour.
Hydration VestsFlask capacity for 100 km, without the bounce.
HeadlampsA 18 h limit puts you out there after dark.
AccessoriesChafe and blisters end more 100 km races than fitness does.

La Sportiva

Prodigio Pro

RunRepeat found the La Sportiva Prodigio Pro to have a secure, locked-in fit due to its premium upper, and also praised the shoe's energetic ride, particularly…

$225 ★★★★★ 4.6

Asics