Vietnam's Swimming Lanes: The Real Gap Sits in the Final 50 Metres

On the final morning of the swimming programme at a SEA Games, I stood in the corridor leading to the main pool, right where swimmers must pass on their way to the ready room. In my hand was the split sheet for the men's 1,500 metres freestyle, printed from the organisers' own data.

The 1,400-metre column said nothing worth noting: the Vietnamese swimmer was still less than two body lengths behind the leader. The 1,450-metre column was where I circled my pencil. The gap roughly doubled inside a single turn. The man beside me saw a medal slip away in the final 50 metres. I saw a problem that had been scheduled twenty minutes earlier.

Numbers only recount. Tactics begin with mistakes.

A swimming nation with a peak but no body

Vietnam is not short of good swimmers. Nguyen Thi Anh Vien once won eight gold medals at a single SEA Games. Nguyen Huy Hoang took bronze in the 1,500 metres freestyle at the 2026 Asian Games, Vietnam's first swimming medal at continental level, and before that a gold at the Youth Olympic Games in the 800 metres freestyle.

But a swimming nation is not measured by its highest peak. It is measured by how many people can swim at ninety per cent of that peak, and can do it three rounds in a row.

At the 31st SEA Games in Hanoi, the Vietnamese team competed in the very My Dinh pool where most of its members train daily. Home advantage in swimming is far smaller than in contact sports. There is no grandstand pressed against the water's edge, no shouting to disturb a breathing rhythm, and water in every 50-metre pool is the same. The only variable is the schedule and the number of swims in a day.

That is precisely the variable Vietnam handles worst.

Reading a race through the split sheet

Split analysis is the only way to read a race. A swimmer in the 1,500 metres freestyle does not swim one straight line. He swims fifteen small straight lines stitched together, and each one carries its own task.

I divide a race into four phases. The opening phase from 0 to 300 metres. The steady phase from 300 to 900 metres. The separation phase from 900 to 1,350 metres. The finishing phase from 1,350 to 1,500 metres.

In the opening phase, Vietnamese swimmers usually do not lose ground. Start technique off the blocks and the underwater segment have improved markedly here over the past seven years. It is also the easiest part to coach, because it lasts about twenty seconds, can be filmed on a phone and counted by eye.

In the steady phase, the gap barely moves. This is Vietnam's comfort zone, and also the zone that creates the strongest illusion. A race that holds its gap for six hundred metres looks a great deal like a race with a plan.

The separation phase is where the bill arrives. From the 900-metre mark, teams with real depth begin to lift the tempo. They do not surge suddenly. They shorten the rest between arm cycles. Stroke rate can stay the same, or even fall, while the number of cycles inside each 50 metres rises.

In the finishing phase, the decisive factor is not top speed. It is the ability to repeat near-top speed while short of oxygen. Put another way, this is a test of the anaerobic energy system, not of stroke technique.

If I had to choose one single indicator for Vietnamese swimming, I would not choose medals. I would choose the spread between a swimmer's fastest and slowest 50-metre split in the same race. Among the region's leading swimmers that spread usually sits between three and four seconds over 1,500 metres. Among Vietnamese swimmers it is generally wider, and the widest point almost always falls at the end.

The conclusion is rarely stated out loud: Vietnam's problem in the pool is not stroke technique. It sits in base conditioning and in how the competition schedule is allocated.

Personal focus: one swimmer doing two jobs

Take a concrete case. A Vietnamese male swimmer races heats in the morning and a final that evening, in the same day, across two different distances. That is the standard competition structure at a SEA Games.

The difficulty is that a heat cannot be swum flat out, but it also cannot be swum as a rest. Swim it too easily and the swimmer arrives at the final with his muscles not properly activated. Swim it too hard and the reserve for the evening is already spent.

Strong teams solve this with depth. They can send one swimmer through the heats at a moderate effort and still have someone else carry the final. Vietnam usually does not have that option. The same person must do both jobs, and must do both well.

That is why I always read the entry list before I read the personal bests. The number of events a swimmer has entered says more than the number of medals he owns.

The overlooked part: turns and underwater work

There is a technical detail spectators barely see, yet it accounts for a serious share of the clock. It is the turn and the underwater segment that follows each turn.

The rules allow a swimmer to travel up to 15 metres underwater after leaving the wall. Across those 15 metres, dolphin or breaststroke kick is usually faster than normal freestyle. Any team that exploits this well saves time at every turn, and a 1,500-metre race contains twenty-nine turns.

This is an advantage that does not require innate talent. It requires repeated correct execution, and a coach who counts the kicks in each underwater segment. Measured in training hours, the cost of improving underwater work is far lower than the cost of raising freestyle speed. Yet it is rarely prioritised, because it is not attractive to watch.

The gap behind a star

The women's events tell the story even more clearly. Nguyen Thi Anh Vien carried almost the entire swimming output of Vietnam across several SEA Games. When she left the stage, the void appeared not in one event but across a whole group of events.

This is the consequence of building a programme around one outstanding individual. Such a programme delivers a very high immediate return, but it does not produce a successor. A successor only appears when a group of five to seven athletes reaches a competitive standard together, and when someone inside that group is constantly pushed upward by the rest.

A swimming nation with depth is not one with many young talents. It is one that keeps its people past the age of twenty.

Relays are the most honest depth indicator

If you want to know whether a swimming nation has a body, look at the relays. A relay entry requires four swimmers who meet a minimum standard, and all four must be present on competition day.

A country can have one swimmer reach a continental final. It cannot have a relay team in that final if it only has one good swimmer. That is why I rank relays above individual medals when assessing a system.

The blind spot in the familiar explanation

One explanation gets repeated often: Vietnamese swimming lacks funding, lacks standards-compliant pools, lacks specialists. All of those reasons are true, and none of them explains the whole gap.

If a shortage of pools were the main cause, provinces with proper pools would produce swimmers steadily. That is not quite what happens. Some localities with good facilities go years without contributing anyone to the national team. Meanwhile a few small centres keep producing people.

The blind spot is in the transition. A Vietnamese swimmer usually peaks between sixteen and nineteen. After that, entering the stage that demands higher training volume and dedicated nutrition and recovery, many of them leave the lanes for university or work.

I do not trust intuition. I trust how many variables that intuition has been loaded with.

Shared training plans and the technical cost

There is another indicator I have tracked for years but rarely written about: how many national-team swimmers have their own coach, against how many must train in a shared group. That ratio reflects how personalised the training plans are.

Swimming is a sport in which personalised plans carry enormous value. Arm span, kick frequency, entry angle, breathing timing: every swimmer has a different optimal configuration. A plan shared by ten people lifts the weakest, and at the same time holds the strongest down.

In strong delegations the common model is a personal coach travelling with a swimmer for years. In Vietnam, the centralised national-team model still dominates. That is reasonable from a management standpoint, but it creates a technical cost that is hard to measure, and that cost usually only shows in the final stretch of a race.

What to watch in the next race

My mistake in 2026 reminds me that data is a mirror, not a lamp.

A mirror tells me where I am standing. It does not tell me which road to take. For Vietnamese swimming, the mirror is showing something fairly clear: the distance to the region no longer sits in the first 50 metres. It sits in the last 50, and in the years after nineteen.

The next race will answer that question. The split sheet does not lie, but it will not swim for anyone either.