Chiang Mai, Thailand · Saturday, October 3, 2026

Fixed Distance 50K

CNX 50K Ultra Marathon

3 days to go

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.

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

What the course asks

Time limit 11 hours 13:12 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 Climbing is unpublished, so this pace is a ceiling on the effort, not a measure of it. More forgiving than 62% of 50K races. Measured against 1034 races of the same distance. Cut-off calculator →

Field size ~108 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, 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.

Results history

Year	Race	Finishers	Men's winner	Women's winner
2025	50km	108	Matee Kampalak · 03:28:35	Nisachon Morgan · 04:19:07
2024	60km	97	Natthaphon Sirisubsuk · 05:09:55	Napaphat Sawangraumchok · 05:23:27
2023	60km	142	Danchai Pankong · 04:27:41	Napaphat Sawangraumchok · 05:30:56
2022	60km	158	Banpot Yeenang · 05:04:07	Sasirada Chanphaeng · 06:02:12

The field grew 11% between 2024 (97) and 2025 (108). 31% of the 2025 field were women.

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.

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

Gear for this race

Chosen for 50 km of trail.

Trail Running Shoes 50 km of trail — cushioning that is still there in the last quarter.
Race Nutrition 50 km of self-supported fuelling between aid stations.
Hydration Vests Flask capacity for 50 km, without the bounce.
GPS Watches Battery life first — a 50 km day outlasts most full-GPS modes.

Adidas

Terrex Agravic Speed Ultra

RunRepeat found the Adidas Terrex Agravic Speed Ultra to be perfect for midfoot and forefoot strikers, while iRunFar noted that the shoe feels incredibly effici…

★★★★★ 4.5

Adidas

Terrex Speed Ultra

RunRepeat found the Adidas Terrex Speed Ultra to have a grippy outsole and great lockdown, while iRunFar noted that the shoe works on a variety of trail conditi…

★★★★★ 4.5

Spring Energy

Awesome Sauce

Real food gel with 180 calories. Rice-based with natural flavors.

$4 ★★★★★ 4.6

Salomon

ADV Skin 12

Industry-standard 12L race vest with front flask pockets and minimal bounce.

$180 ★★★★★ 4.8

COROS

APEX 2 Pro

GPS running watch with 75-hour GPS battery, topo maps, and training metrics.

$500 ★★★★★ 4.7

All gear guides →

Overview

The CNX 50K Ultra Marathon, organised by Thailand Ultra, is a 50-kilometer road race in Chiang Mai, Thailand, with its next edition on October 3, 2026. This race has been run 4 times, with the most recent edition in 2025 seeing 108 finishers.

With a time limit of 11 hours, the 13.2 minutes per kilometer cutoff pace is tighter than 34% of 50k races. The field size is larger than 80% of its 2660 peer 50k races, making it a comparatively well-attended event.

Similar races

Other 50K trail ultras, closest in distance first.