Chiang Mai Thailand by UTMB (formerly Doi Inthanon Thailand by UTMB)
Doi Inthanon – Thailand by UTMB (Summit 160)
Chiang Dao (Wat Tham Chiang Dao) → Chiang Mai (PAO Park)
Race guide
Updated 19 July 2026
The Summit 160 — part of the Doi Inthanon Thailand by UTMB series, now running under the Chiang Mai Thailand by UTMB banner — is one of Southeast Asia's most demanding ultra-distance races. Covering 178 km from Wat Tham Chiang Dao (436 m) to Chiang Mai's PAO Park (320 m), it packs 8031 m of total climbing into a point-to-point route that sweeps through the forested ridges and valleys of northern Thailand's mountainous interior. The high point sits at 1730 m, which in the context of Thai terrain means relentless, punchy climbing rather than sustained alpine altitude — legs and lungs are tested by repetition and heat, not by thin air. This is a race that rewards temperament as much as fitness. The rolling opening valleys and accessible early terrain create a seductive sense of ease that has caught out hundreds of runners who hit the back half of the course already spent. Understanding that the real race begins only after the first night — and that a patient, almost social early pace is a direct investment in a strong finish — is the single most important strategic insight any runner can carry into Chiang Dao.
Course & Terrain
The route runs point-to-point from Wat Tham Chiang Dao in the north to PAO Park on the southern edge of Chiang Mai, threading through the forested hills and agricultural valleys characteristic of Chiang Mai Province. With 8031 m D+ distributed across 178 km, the average gradient is deceptively moderate on paper, but the climbing arrives in concentrated bursts — steep, rooted singletrack through dense jungle canopy — rather than as long, measured ascents. The high point of 1730 m sits well below the oxygen-thinning elevations of alpine ultras, but the cumulative heat and humidity at lower elevations extract their own toll, making this a physiologically distinct challenge from European mountain races of similar distance. The terrain underfoot shifts markedly across the course: hard-packed dirt roads and wide valley tracks in the opening sections give way to technical jungle singletrack, river crossings and root-strewn ridgelines as the route moves deeper into the hills. Traction is generally reliable in dry conditions but the forest floor can become genuinely treacherous after rain, with red clay and exposed roots combining to slow technical descents considerably. Trail shoes with aggressive lugs and good protection underfoot are the sensible choice for the full distance.
The Decisive Climbs & Where the Race Is Won or Lost
Because the elevation profile spreads its 8031 m across nearly 180 km, there is no single iconic climb that defines the Summit 160 the way a Col de la Croix du Bonhomme or a Grand Col Ferret defines a European classic. Instead, this race is decided by accumulated fatigue management over multiple concentrated ascent-and-descent cycles through the middle and later sections of the course, typically encountered deep into the first or second night of racing. Runners who have burned through glycogen reserves and mental reserves in the fast, runnable opening terrain arrive at these climbs with nothing left; runners who treated the early valleys as an enforced warm-up arrive able to move with genuine purpose. The back half of the course — after the first night has passed — is where positions are made and lost. Descents in the jungle heat demand focus and controlled technique; a rolled ankle on a rooted descent 120 km in can end a race that was otherwise well-executed. Prioritise consistent effort over chasing pace on every climb, and treat each descent as an opportunity to recover the legs rather than to make up time aggressively.
Pacing Strategy
The community consensus from runners who have excelled here is unambiguous: go out easy, even uncomfortably easy, through the opening valleys. The accessible early terrain — wide tracks, gentle gradients, the social energy of race start — creates powerful pressure to run faster than planned. Resist it entirely. A first half that feels almost too relaxed is not a wasted opportunity; it is the direct deposit that funds whatever you have left when the course turns serious in the second half of the night and beyond. The proven approach is to run the first half almost socially — conversational effort, eating proactively, staying mentally calm — and then gradually unlock pace as the field thins and fatigue separates those who were patient from those who were not. In the heat of the Thai day, break the remaining distance into small, manageable segments rather than confronting the full remaining kilometres as a single number. 'Two more checkpoints and I'm home' is not a psychological trick; it is a structured way to keep effort calibrated and avoid the spiral of heat-induced demoralisation. The runners who have set fastest times here report that records came from going easy early, not from going hard from the gun.
Fuelling & Hydration
With a finish cut-off at Day 10:00 at PAO Park and a total distance of 178 km, most competitive runners will be on course for somewhere between 24 and 40-plus hours, crossing at least one full night and a significant portion of one or two full days. This means multiple fuelling cycles — the race is long enough that reliance on any single food type will almost certainly result in flavour fatigue and gut revolt. Plan for variety: a mix of savoury and sweet, solid and liquid, familiar Thai checkpoint foods alongside whatever personal race nutrition you are trained on. Hydration is the critical variable in this part of the world. Northern Thailand's humidity means sweat rates are high even when perceived effort feels moderate, and dehydration can creep up before thirst signals arrive. Carry sufficient capacity between checkpoints, prioritise electrolyte replenishment over plain water, and use every crew access point — including the start at Wat Tham Chiang Dao and the finish at PAO Park — to reset nutrition and fluid stores. Gut issues in the heat are common; train your stomach for running in warm conditions before race day, and err toward easily digestible options during the hottest hours of the course.
Conditions to Expect
Chiang Mai Province in race season brings warm to hot daytime temperatures with high humidity, particularly at the lower elevations that bookend the course. The jungle sections provide shade but trap moisture, meaning the effective felt temperature in dense forest can be as high as or higher than in open valley sections. Night temperatures at the 1730 m high point will feel cool by contrast, making layering essential — a light wind shell and a thermal layer for the small hours are not luxuries on a 178 km race in the hills above Chiang Mai. Rain is a realistic possibility depending on the exact timing of the edition, and the jungle terrain changes character significantly when wet — expect slower times, more careful descending and the need for waterproof kit in your pack. Dust can be a factor on drier editions, particularly on the wider tracks. Sun protection for any section run in daylight is non-negotiable: sunscreen, a buff or cap, and sunglasses should be standard kit from the start at Wat Tham Chiang Dao through to the finish at PAO Park.
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Checkpoints & cut-offs
✓ Course data verified against the official source (2026-07-05) · official source
0 km · 431 m · —
9.3 km · 458 m · —
22.7 km · 761 m · —
32.8 km · 1566 m · Fri 19:00
42.9 km · 1060 m · —
51.1 km · 527 m · Fri 23:00
64.5 km · 1248 m · —
71.5 km · 712 m · Sat 04:00
82.5 km · 666 m · —
92.4 km · 1056 m · —
100.2 km · 723 m · Sat 12:30
109.9 km · 843 m · Sat 17:00
115.4 km · 1238 m · —
129.3 km · 528 m · Sat 23:59
138.6 km · 1015 m · —
148.5 km · 1400 m · —
161.8 km · 692 m · Sun 08:00
172.7 km · 320 m · Sun 10:00
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