VMM 2026 in Sa Pa: A Sawtooth Trail and the Test of 5,300 Pairs of Legs

At 8 a.m. on September 18, in Sa Pa, the starting horn sounded. The 161 km and 100 km distances of the Vietnam Mountain Marathon 2026 poured onto the trail at the same moment. I sat in front of a screen in Melbourne, nearly seven thousand kilometres from the start line, and the first thing I opened was not the results page, but the elevation profile. A sawtooth. Peaks joined to each other by ravines, with no flat stretch long enough to reset your breathing. I keep an old habit: record everything, even when I am only watching. Once I mispronounced a name at a World Cup qualifier and spent the whole night rewatching my own recording. The tape is the harshest spectator. With VMM 2026, that harsh spectator is the elevation chart and the weather data, two things that do not lie. The event runs from September 17 to 20, 2026 in Sa Pa, Lao Cai province. The organiser is BTC VNM 2026. The most notable development: VMM has officially joined the World Trail Majors system, the group of major international trail races, entirely separate from the ATP or WTA tennis circuits I cover week in and week out. This year's scale: more than 5,300 athletes from 54 countries. The main distances are 100 km and 161 km. Record rain, slippery trails, and the highest recorded difficulty in the event's history. The organiser set up rope-assisted descents and rock slabs as slick as natural slides. Fog cut visibility on many sections. Champions will be determined on September 19. The meaning of joining the World Trail Majors goes beyond a single press line. The system imposes entry standards and a fixed calendar slot. In other words, VMM is no longer a spontaneous playground for locals and a handful of adventure tourists. It has become a node in the international endurance-sport supply chain, where results are cross-checked across borders, where an athlete in Nepal or Spain has a concrete reason to book a flight to Lao Cai. That is why I do not read VMM 2026 as a travel story. I read it as an operations problem. The first analytical layer sits in the elevation profile itself. A sawtooth means the body is never allowed to switch into economy mode. On flat ground you can lock your heart rate in a stable zone and let your legs work like a machine. The sawtooth takes that right away. Every climb burns the quadriceps; every descent burns the hamstrings and calves in a completely different way. Two muscle systems are drained in turn, with no rest interval between them. The interesting part is that most amateur athletes train hard for the climbs — they climb stairs, they run hills, they measure VO2max. But the killer section is the descent. Descending a slippery trail is its own skill: knees slightly bent, centre of gravity low, eyes fixed three steps ahead rather than on the toe of your shoe. I once stood in the technical zone of an athletics meet and saw it clearly: the best flat-ground runner is often the worst descender, because they trust momentum. At VMM 2026, record rain turns descent skill from a bonus into a survival condition. The rope sections are not there to climb up — they are there to hold on going down. When rock is as slick as a slide, speed is no longer decided by fitness but by terrain reading. An athlete who is slower over 10 km on flat ground can pass a stronger one here, simply because the stronger one knows when to brake. Act first, analyse after — I learned that from the 360-degree camera at the World Cup. That angle taught me that football is not in the ball, but in the space around it. Trail running is the same. The race does not happen on the climb you see on the elevation chart, but in the rest gap between two peaks — where you think you are being let off. That gap is the trap. After a long climb, the body signals "done", and the natural reflex is to ease off. But on a sawtooth, a short flat is only a springboard for the next climb. Experienced athletes use the flat to refuel, drink, check their feet — they do not use it to rest. The difference between finishers and dropouts at 161 km usually lies not at the highest peak, but in those brief flats that get underestimated. Another layer rarely discussed: the 100 km and 161 km distances start together, on the same day, at the same hour. Organisationally this is a sensible choice — optimising staff and aid stations. Competitively, it creates a strange ecosystem. The 100 km runner knows they will leave the course early; the 161 km runner knows there are more than 60 km of darkness still ahead. For the first hours, the two groups run side by side, sharing the same water station, the same fog bank. Then at a fork they split, and the loneliness begins. At 161 km, most of the race happens at night. This is where pure fitness analysis becomes meaningless. On a mountain at night, what defeats people is not altitude but circadian rhythm. The body is not programmed for hard exertion at 2 a.m. Heart rate drops, reflexes slow, and worst of all, visual hallucination — seeing trail where there is no trail. Fog makes it worse, because limited visibility is squeezed further into the beam of a headlamp. In those conditions, an aid station is no longer a place to drink. It is a ritual. Sit down, change socks, apply vaseline, eat something salty, then stand up before your body can convince you to stay. I have watched medical stations at endurance events, and the common trait of dropouts is not serious injury. They sat down once for too long. From a 360-degree angle, VMM 2026 is not a single race. It is three races stacked on top of each other: the race against terrain, the race against weather, and the race against the decision to sit down five minutes longer. Now the part I want to say plainly. The media calls VMM "Vietnam's harshest marathon". That phrase sounds attractive, but it is a slogan rather than a measurement. Nobody defines "harshest" by anything — elevation, temperature, dropout rate, or injury count. When an event pins an ultra-tier label on itself, invisible pressure falls on the organiser to live up to it. And that pressure can conflict with something more important: safety. Rope-assisted descents and slick slabs are evidence. That is a natural feature of the terrain, created by no one. But the decision to still send athletes through it in record rain is an operational one. I do not have enough data on the organiser's safety deliberation process. I only know that at events I have followed live, the criterion of "harshest" and the criterion of "safest" rarely point the same way. An empty bench is not a collapse — it is a piece for a story nobody has told. At VMM 2026, the "empty bench" is the athletes who could not start, the medical stations that closed early, the sections cut from the race map that spectators will never know about. The untold story of an endurance event is not the winner. It is the three-hundredth finisher, the one who went through everything and is never named. One more point I want to view with sober eyes. The presence of actor Nhan Phuc Vinh — a face known in artist trail-running circles — brought the event considerable attention. Netizens expressed excitement and admitted admiration for the athletes' endurance. I understand that pull, and I do not dismiss it. But I also know the flip side: when the spotlight turns to a celebrity, it unintentionally diminishes everyone else. An amateur who completes 100 km in the rain at night deserves to be told as an athlete, not as a spectator standing next to someone famous. I once dropped my voice before a World Cup qualifier — I got back up because I hate the tape but I need it. My profession taught me that the emotion of the crowd is a signal, not evidence. Admiration is a beautiful emotion, but it does not measure difficulty. Only elevation, temperature, rainfall and completion rate do. So what actually draws 5,300 people from 54 countries to a mountain town in Lao Cai? I think the answer is not glory. At 161 km, nobody signs up for the prize. Most know they have no chance of a podium. They come for something harder to explain: the need to test their own limits in an environment that cannot be faked. The trail does not negotiate. The mountain does not know who you are. The rain does not care which title you once won. That is why I follow endurance events even though my main job is tennis reporting. Not because I want to compare them. But because both teach the same lesson in two different languages. Tennis teaches decision-making in an instant. Trail running teaches decision-making in silence, when there is no grandstand, no umpire, and nobody knows whether you just quit or just kept going. In the next two days, the organiser will announce the champions. There will be a name, a finishing time, a photograph. And very quickly after that, it will all sink. But one number will linger longer: the ratio of entrants to actual finishers. That is the most honest index of a trail race, because it is not measured in sponsorship money or engagement, but in how many people stood up at the last aid station when their body told them to stop. If you follow VMM 2026 as a results board, you will miss most of the story. My advice: open the elevation profile first, then open the results. The 360-degree camera taught me that. It is always the same: the real contest is not at the finish line, but across the whole space people crossed to get there.