IRONMAN · Da Nang · 9 May 2027
How to train for IRONMAN Vietnam
Da Nang sells a fast day. The organiser calls the bike flat, describes 108 km of traffic-free straightaways built for speed, and promises you will learn the loop the first time round and fly through it the second. All of that is true. None of it is what decides the race.
What decides it is the air. Over the three editions the organiser logs, the high never dropped below 33 C and the low never below 25 C. The demand model scores environmental resilience at 90 on the swim, on the bike, on the run. Only the endurance scores rank above it, and a Trained athlete spends 12:01:05 inside it.
By Kian Briel, founder. Analysed by engine 1, updated
What is actually on the road
The organiser's own course files, drawn the way the Event Analyzer draws a member's race.
- Swim3.85 km7 m upCourse file
- Bike181 km in 2 laps164 m upCourse file
- Run43 km27 m upCourse file
The day starts and ends at East Sea Park. The swim is 3.9 km of sea from a rolling start, two consecutive clockwise laps of a triangle with two red buoys at the turns, then straight up the beach into a transition that serves as T1 and T2 at Bien Dong Park.
The bike leaves along the Vo Nguyen Giap and Hoang Sa coastline, turns inland for 11 km on the eastern bank of the Han River, then heads into Quang Nam for a 16.5 km straight on Lac Long Quan Road. It climbs Cua Dai Bridge onto Vo Chi Cong, and that road is the engine room of the day: 2 laps of 54 km out to the A2 turnaround and back, 108 km in all. Then over the bridge again and home the way you came, with the organiser promising the ocean breeze at your back on the final stretch.
The run is four out-and-back loops of 10.5 km on Vo Nguyen Giap Road beside the beach, with the crowd along the beachfront and the finish back at East Sea Park.
The profile has almost nothing on it. 164 m of climbing on the bike, 27 m on the run, and one rise of any note in the whole file, 733 m at 3 percent. The engine splits the bike at that rise into two flat stretches. The first 40 km hold 22 percent of the leg. The remaining 140 km hold 78 percent, the largest single block of time anywhere in the race.
Course shape by distance
- Flat 100%
- Climbing 0%
- Descending 0%
The longest stretches
- Bike, flat40.1 km22% of the bike
- Bike, flat140 km78% of the bike
- Run, flat43 km100% of the run
Each row is one unbroken stretch of the course that keeps the same shape the whole way. The number is how much of that leg you spend inside it, and it comes out the same whether you are fast or slow.
What this course asks of each leg
Twelve training dimensions scored for each leg against its own course, the way the Event Analyzer scores a member's race.
At 95, aerobic endurance leads on all three legs. On the bike, aerobic durability and muscular endurance sit at 90 right behind it, level with environmental resilience. The run lifts durability to 95. Fueling resilience reads 85 everywhere. Then there is a long drop. Threshold capacity reads 55. On the bike, the strength score is 45 and high-intensity capacity 27. A course this flat does not ask you to be strong or sharp.
The swim carries a score the other legs do not. Technical skill reads 83 in the water against 40 on the bike and 47 on the run. It is open sea, clockwise, with a rolling start that spreads the field and leaves you sighting on your own.
Now the bands. A Trained athlete swims 1:20:59, rides 6:09:15 at 159 W and runs 4:20:51, a day of 12:01:05 in which the bike is 51 percent. The Competitive band, at 10:27:47, rides 5:26:07 from 4.15 W/kg at 75 kg and runs 3:41:38 from 4:20 /km threshold pace. Both of them ride the same flat road. What differs is how much power each can hold on it in 35 C air and still run a marathon afterwards.
- Aerobic endurance95
- Aerobic durability90
- Environmental resilience90
- Muscular endurance90
- Fueling resilience85
- Technical skill83
- Threshold durability80
- Threshold capacity55
- High-intensity capacity25
- Strength / force25
- Anaerobic capacity15
- Sprint power0
Nymiva reads what you can already show, from your own data
Connect your training history and the Focus Lab scores the same twelve dimensions this course demands against where you sit today. The gap between the two is what you train.
- MeasuredFrom your thresholds and testsThreshold power, threshold pace, critical swim speed and field tests you have done. The dimensions they can carry are scored directly.
- EstimatedFrom your training historyConnected activities are read for what they prove: long efforts, late-session fade, repeated hard work, fueling on long days. Each score says how it was read.
- ProxyFrom a stand-in, and named as oneWhere only an indirect signal exists, the score carries the proxy it came from and a lower confidence, never a number dressed as a measurement.
- UnmeasuredHonestly blankA dimension nothing in your data can answer stays unmeasured. It is never a zero, and the plan does not pretend to know it.
Every dimension ends in one word
- Develop the course asks more than you can show
- Maintain close enough to hold at the minimum dose
- Covered nothing to build here
- Unmeasured the course needs it, your data cannot say yet
Nymiva scores the athlete on the same twelve dimensions it uses for the course, reading them from thresholds and connected training history and saying beside each score where it came from. A gap exists only where the course asks for more than the athlete can show. Gaps are then ranked by how much of the day they fill, which on a course where the bike takes half the day puts the bike's gaps first.
With no reader's data on this page, the season makes the simplest assumption available: the gaps sit where the demands are highest. It lays out 28 weeks in 3 developmental blocks and a two-week taper. Aerobic endurance leads the first block in every sport. Fueling resilience leads the second. Aerobic durability leads the last block before the taper. A member's own season starts from their numbers and will not look like this one.
Train the bike to protect the run
Which demands matter most across the whole race. A leg's demand counts for as much of the day as that leg takes, so a score of 85 on the bike outweighs the same score on the swim.
- 01Aerobic enduranceBike leg, 51% of the day95 × 51%49
- 02Aerobic durabilityBike leg, 51% of the day90 × 51%46
- 03Environmental resilienceBike leg, 51% of the day90 × 51%46
The bike takes 51% of the Trained reference band’s day, so its demands carry the most race weight. What the bike leaves in the legs is what the run gets.
Which demand gets a block, and when
The engine freezes one lead focus per sport on every developmental block, holds the rest at maintenance, and verifies before it reprioritises.
An illustration, not your plan. This page has none of your data, so the season below is the engine’s answer to one stated assumption: that your gaps line up with what IRONMAN Vietnam demands. Your own season is built from your history, your thresholds, the days you can train and the races you have entered, and it will differ from this in its priorities, its sessions and its load.
- 01Run aerobic endurance, a development block4 weeks
- 02Run aerobic durability, a practice block6 weeks
- 03Bike aerobic endurance, a development block9 weeks
In the order the allocator places them, general first, most race-like last.
- Week 1PrepPrep
A lead-in week. It develops nothing by design.
- Weeks 2 to 9Foundation 2Closes with a recovery week
- PriorityBike aerobic endurance
- PriorityRun aerobic endurance
- PrioritySwim aerobic endurance
- SupportRun aerobic durability
- SupportBike aerobic durability
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim aerobic durability
- SupportSwim muscular endurance
- SupportBike fueling resilience
- SupportRun fueling resilience
- SupportSwim fueling resilience
- Weeks 10 to 17Event shaping 1Closes with a recovery week
- PriorityBike fueling resilience
- PriorityRun fueling resilience
- PrioritySwim fueling resilience
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportRun aerobic durability
- SupportSwim aerobic endurance
- SupportBike aerobic durability
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim aerobic durability
- SupportSwim muscular endurance
- Weeks 18 to 25Event shaping 2Closes with a recovery week
- PriorityRun aerobic durability
- PriorityBike aerobic durability
- PrioritySwim aerobic durability
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike fueling resilience
- SupportRun fueling resilience
- SupportSwim fueling resilience
- Weeks 26 to 27PeakPeak
The taper. Load comes down toward the race, content stays specific.
- Week 28RaceRace
Race week.
Held at maintenance between blocks
- Runaerobic endurance, aerobic durability, threshold durability, muscular endurance, fueling resilience
- Bikeaerobic endurance, aerobic durability, threshold durability, muscular endurance, fueling resilience
- Swimaerobic endurance, aerobic durability, threshold durability, muscular endurance, technical skill, fueling resilience
Touches scheduled by each capability’s own decay, at a fraction of its development dose, so earlier work is still there on race day.
The sessions the blocks are built from
One entry per kind of work the block trains, at the intensity that work is meant to be done at. Where the same work runs at several lengths, the entry shows the span it grows across rather than one entry per length.
- Foundation 2 · Weeks 2 to 975 to 240 min
150 to 210 min at Zone 2
BikePower, Zone 2Trains aerobic capacity - Foundation 2 · Weeks 2 to 940 to 270 min
180 to 210 min at Zone 3, then 30 min at Zone 4
BikePower, Zone 3Trains aerobic capacity - Foundation 2 · Weeks 2 to 935 to 120 min
90 min at Zone 2
RunPace, Zone 2Trains aerobic capacity - Foundation 2 · Weeks 2 to 950 min
4 x 1.5 min at Zone 3, 6 min easy between
RunHeart rate, Zone 3Trains aerobic capacity - Foundation 2 · Weeks 2 to 945 to 51 min
4 x 8 min at Zone 2, 1 min easy between
SwimPace, Zone 2Trains aerobic capacity - Foundation 2 · Weeks 2 to 947 to 81 min
3 x 1000 m at Zone 3, 0.3 min easy between
SwimPace, Zone 3Trains aerobic capacity
Sustained course race pressure
60 min at Zone 4
Compiled by the deterministic course compiler from the organiser’s file: the course’s one repeatable requirement, rehearsed at a dose the progression allows.
- Bike
- 85 min
- Trains threshold durability
- Supports aerobic durability
28 weeks, laid out backwards from race day
The shortest runway Nymiva builds for this event type, with its blocks, recovery weeks, taper and race week in place.
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- 9
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- 11
- 12
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- 28
- Prep
- Foundation
- Event shaping
- Peak
- Race
- Recovery week
Your own season carries these same phases on your own dates, with the load solved from your fitness and the days you can train, and it changes when your data does.
What each level does on the day
Reference finish times per peer band, the pacing plan the model holds each band to, and where the day is decided.
| Band | Swim | Bike | Run | Finish |
|---|---|---|---|---|
| Recreational2:11 /100m critical swim speed · 2.47 W/kg at 75 kg · 6:08 /km threshold pace | 1:35:34 | 6:41:19 | 5:13:42 | 13:40:35 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 1:20:59 | 6:09:15 | 4:20:51 | 12:01:05 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 1:10:02 | 5:26:07 | 3:41:38 | 10:27:47 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 1:02:44 | 4:57:32 | 3:16:04 | 9:26:20 |
Pacing plan
- 0 km0%29.2 km/h1:22:28
- 40.1 km3%16.2 km/h2:43
- 40.9 km0%29.2 km/h4:48:12
- Run: reach 4:20 /km and this course gives back 1:33:18.
Where it is decided
On Vo Chi Cong, twice.
The organiser built that road for speed and says so. Two 54 km loops, closed to traffic, dead straight, flat enough that the file reads the whole thing as one piece. Every rider on it feels quick, and every rider on it is spending. The engine, asked to build a session from this bike, prescribes no intervals at all: a warm-up, then sixty unbroken minutes in Zone 4, then a short spin down. It treats the leg as one long effort with no natural break, because on this course that is what it is.
The Trained reference holds 159 W for 6:09:15. A rider who takes the first loop at time-trial effort because the road invites it has not ridden that plan, and the second loop will tell them, with the heat doing the telling. The run then begins on the beachfront, flat, four times out and back, 4:20:51 for a Trained athlete from an input of 5:06 /km threshold pace. The flat run does not rescue a hot bike. It exposes it.
Getting it wrong
Taking the organiser at its word on the second loop. "Fly through" is a line for a brochure. The second lap on Vo Chi Cong is the one ridden deeper into the heat of the day, and it should be ridden at the power of the first, not the speed.
Trusting the tailwind home. The organiser says the ocean breeze is at your back on the final stretch to East Sea Park. If the wind helps you home, it held you back somewhere earlier, and a rider who pushed into it to keep the speed up has already paid.
Running the first loop to the crowd. The beachfront is loud, the aid stations come quickly, and the turnaround arrives before you have settled. Loop one feels like the easiest running you will do all day. Four loops in 34 C heat is a long way from easy, and the pace you choose on the first one is the pace the fourth one pays for.
Conditions on the day
- 2026high 33 C, low 25 Cwater 29 C
- 2025high 35 C, low 27 C
- 2024high 34 C, low 25 C
From the organiser’s own records. Not a forecast.
Every session is a claim, every block is a test
A plan is not a calendar. Each key session states what it trains and how that is checked, and each block ends with a public verdict before the next one is chosen.
What a block promises
Bike aerobic endurance moves from your baseline to a stated target by the end of Foundation 2
- The baseline is your measured score when the block starts. The target is the score the model predicts for it.
- Verified at the block’s recovery week, by a field test or a refresh of the supply read from your history.
- Confidence rises by agreement between independent signals, never by one metric crossing a line.
- A block that misses its target is a public miss. The next block is chosen from what was proven, not from what was planned.
- 01Stimulus achievedThe work landed in the zone the session named, for the dose it named.
- 02Partially achievedSome of the work landed. The session banks what it can prove.
- 03Not achievedThe load may have been there. The stimulus was not, so nothing is banked.
- 04Data insufficientNo usable stream. The session is neither credited nor blamed.
- Session verified
- Progression banked
- Block verified
- Priority reassessed
- Plan adapted
Your numbers, this course
Analyze IRONMAN Vietnam against my fitness
The same simulation and the same Focus Lab read, on your thresholds instead of a band’s. Three numbers give a finish estimate and a partial read. A connected history gives the whole table.
The first 14 days are free.
- Trained band finish
- 12:01:05
- Of the day on the bike
- 51%
- Dimensions scored per leg
- 12
- Season runway shown
- 28 wk
Questions people ask
- How flat is the IRONMAN Vietnam bike course?
- Almost entirely flat. The file measures 164 m of climbing over 181 km, and the only rise of note is 733 m at 3 percent. The organiser describes 108 km of traffic-free straightaways on two loops of Vo Chi Cong, with a crossing of Cua Dai Bridge on the way out and again on the way back.
- How hot is IRONMAN Vietnam?
- The organiser logged highs of 34 C in 2024, 35 C in 2025 and 33 C in 2026, and the low never fell below 25 C. The sea at East Sea Park read 29 C in 2026.
- What is the IRONMAN Vietnam run course like?
- Four out-and-back loops of 10.5 km on Vo Nguyen Giap Road, along the beachfront from East Sea Park. It is flat, with 27 m of climbing in the file, and the organiser places aid stations at short, regular intervals along it.
- How long should an IRONMAN Vietnam training plan be?
- The illustrative season on this page runs 28 weeks, with three developmental blocks and a two-week taper. It is built from the course alone. A member's season starts from their own numbers and can be longer.
Course data from the organiser’s published files, analysed 24 Sept 2026 by engine 1, demand model 4. Reference times are simulated for a peer band at a stated reference athlete and are not a prediction for anyone. Nothing on this page is medical advice.
IRONMAN® and IRONMAN 70.3® are registered trademarks, and 5150 is a trademark, of World Triathlon Corporation. Nymiva is an independent training platform and is not affiliated with, sponsored by or endorsed by World Triathlon Corporation. Course data is read from the organiser’s public course pages for the purpose of describing the event.