HDBank Green Marathon 2026 in Can Gio: AIMS Certification, a Mangrove Route, and the Gender Data Gap

Binh Khanh ferry terminal, 4:40 in the morning.

The woman stood alone at the head of the pier, a cloth bag at her feet, her laces tied loose. The first ferry to Can Gio was ten minutes out. She told me her son was in sixth grade, her husband had entered the 42 km, and she had entered the 21 km. She repeated the line twice, like a contract clause: "After I finish I still have to get back in time to take my son to class."

I carried that line through the whole season, not because it was sad, but because it was a technical datum disguised as a life story.

The HDBank Green Marathon 2026 has announced its fifth season, scheduled for September 2026 in Can Gio district, Ho Chi Minh City. The organisers have kept the familiar set of distances: 5 km, 10 km, 21 km and 42 km, plus children's and team categories. The route is distance-certified to AIMS standards. The event is held under the guidance of the Ho Chi Minh City Athletics Federation, includes an online component called Green Marathon online, and according to figures from previous seasons, more than 2,000 trees have been planted along the course.

That is four lines of a press release. The rest of this article lies in the space between those four lines.

Can Gio is Ho Chi Minh City's only coastal district, roughly 50 km by road from the city centre plus a ferry crossing. Most of its area is mangrove forest, recognised by UNESCO as a World Biosphere Reserve. A race here is not like a race in an inner-city park. The surface changes constantly: concrete, packed earth, beach sand, roots pushing up on the stretches that run deeper into the forest. High humidity and sea wind produce a kind of energy drain that a heart-rate monitor does not fully display.

For the organisers, this is a logistics problem: water, medical cover, rescue, aid stations, cut-off times, and a course that cannot be expanded indefinitely. For runners, it is a pacing problem. For me, it is a problem of arithmetic about presence.

I have spent most of my career writing about athletics counting who is present and who is absent. On the stands in Russia, I heard many empty seats bearing women's names. At Vietnamese community races, those seats are not empty in that way. They are empty differently: people still stand on the start line, just at shorter distances.

The distance structure of a community race is a social map drawn in kilometres. The 5 km is the doorway. The 10 km is the corridor. The 21 km is the living room. The 42 km is where people sign a different kind of contract with themselves.

Based on my experience following grassroots races domestically, the female participation curve drops steeply between 10 km and 42 km. At 5 km and 10 km, women usually make up a substantial share, at some races close to half. At 21 km, the share falls. At 42 km, some races are left with only a few dozen women out of several thousand entrants. I do not have official HDBank Green Marathon figures, and that is the first point to make: a race now in its fifth season that does not publish data broken down by gender and distance is wasting the cheapest equality-measuring instrument it already owns.

Distance is also time. A woman running 42 km needs roughly four to five hours on course, plus travel from the city centre to Can Gio, plus ferry waiting time in both directions. A full morning, sometimes a full day. If the 42 km cut-off is designed for someone with the whole day free, who is it designed for?

Mangrove terrain makes that equation harder. The course has sand, roots and narrow sections. For a runner at five minutes per kilometre, terrain error costs only seconds per kilometre. For a runner at eight minutes per kilometre, the same stretch costs relatively more energy, because the time spent in contact with poor surface is longer. One course, but not one race. That is why community events should publish a kilometre-by-kilometre terrain profile instead of a single shared map.

What does AIMS certification actually solve? It confirms the distance has been measured and checked to international standards, reducing technical risk for participants and allowing performances here to be compared with other road races. For a community event, it is a guarantee of safety and accuracy. It says nothing about competitive quality. The two are routinely merged into one in press communications.

The Green Marathon online component is structurally the most interesting part. It pulls the event out of a single Sunday morning and turns it into a sustained training process. As movement-building, this is the right direction: beginners need a reason to keep going week after week, and a race only has one day. As data collection, it is also how organisers learn who is actually running, at which distance, at what pace.

The distance between having data and publishing data is the entire story.

Forty-five minutes on the sidelines, a lifetime that never grows old. At a race, those 45 minutes sit before the starting gun: queuing for the toilet, retying hair, checking the water flask, telling a child to stand in the right place. For men, that is usually 45 minutes of warming up. For women, it is usually 45 minutes of warming up plus three other tasks. No statistic records that part, but it lives inside every decision about which distance to enter.

When the stadium is empty, ordinary voices become leaders. At grassroots races in southern Vietnam, those leaders are usually the volunteer coaches of weekend running groups, most without contracts, without payroll, and without a place on any list. They are the ones who walk someone who has never run past 3 km to the start line of a first 10 km. If Vietnamese women's running has real infrastructure, it is there, not in the stadium.

Vietnam does not lack elite women at endurance distances. The problem is at the base of the pyramid: the number of women confident enough to stand in the 42 km pen at a grassroots race. That figure decides how many female marathoners the country has in ten years, not the medal count at one Games. And it cannot be improved with slogans. It improves only by lowering the barriers to entry: sensible cut-offs, childcare, pace groups, and an honestly described course.

If I had to pick one sentence about how Vietnam's big community races are communicated, I would say this: commercial value is being written in the language of competitive value.

An AIMS certificate is a technical certificate for a distance. It is not a sporting honour. A race with no elite athletes is not worth less because of that. But when a press release uses phrases like "international standard", "prestige" or "thousands of runners", readers easily misread it as an elite competition. That confusion does not harm the organisers. It harms the movement, because it forces community races to compete in the language of things they do not have, instead of the thing they genuinely have.

What they genuinely have is a course few places in the world can offer: dozens of kilometres through mangrove forest, a biosphere reserve, a morning in Can Gio. No medal buys that advantage.

The green part also deserves to be stated accurately. Planting more than 2,000 trees is a verifiable figure, and sustaining it across seasons is worth noting. But there is a structural question: if every race bib comes with an interaction on a banking app, which part of the event serves the environment and which part serves a customer funnel. The answer can be both, and that is normal. It just needs to be called by its name. A contract has an expiry date; a human story does not.

The most regrettable part is not on the sponsor's side. It is on the data side. After four seasons, the organisers certainly hold detailed registration records for thousands of people: age, gender, distance, finish time, drop-out rate. That is the richest dataset on southern Vietnam's running movement, richer than any interview. Publishing it would not reduce the race's commercial value. It would turn the race into something else: a reference point.

A fifth season is a milestone long enough to start measuring rather than merely describing. If in September 2026 in Can Gio the organisers publish one small table showing the female share by distance, it will be the most valuable sporting datum of that day. Looking at a scoreboard, I learned to read what is not written down. A race entry list works the same way.

And if the woman at Binh Khanh ferry terminal moves from 21 km to 42 km, I want to know what changed for her to gain an extra hour and a half.