IRONMAN · Penghu · 11 Apr 2027
How to train for IRONMAN Penghu
The organiser's own summary of this race names the scorching heat first. Then the strong winds. The ups and downs of the course come last. Most athletes read that order backwards. They see a rolling bike on the map, spend the winter riding hills, and arrive in April on an island in the Taiwan Strait ready for the one thing Penghu asks for least.
The file puts the ups and downs in their place. Across the whole race, 95.9 percent of the distance is flat. The steepest climb on the bike takes a Trained rider a couple of minutes and a fraction of one percent of the leg. The heat and the wind, which no profile can draw, are with you for all 12:03:31 of the same rider's day.
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.
- Swim3.84 km12 m upCourse file
- Bike178 km in 3 laps803 m upCourse file
- Run42.2 km in 2 laps79 m upCourse file
Two counter-clockwise laps of a triangle make up the swim, 3.8 km of sea. Between them you go ashore and enter the sea again, which breaks the rhythm once and gives you a look at the clock.
The bike starts on Route 201 and turns onto Route 204, where the first aid station stands at Guoye Elementary School. It passes Husi Junior High School, takes Routes 11 and 12, then settles onto the long Route 203. That is where the race lives. You cross the Penghu Great Bridge and ride 3 laps between turnaround A and turnaround B, which sits at the Xiyu West Fort parking and holds the special needs station. Then back past Tianjun Temple to T2. You pass an aid station ten times over the whole leg.
The run leaves T2 onto Tonghe Road. You run two laps of one stretch and two of another, collecting four lap bands, past the Guanyinting Recreation Area, the Xiying Rainbow Bridge and the bronze Matsu statue the organiser calls the tallest in the world. The file measures 79 m of climbing over the marathon.
Now the profile. The bike measures 803 m, but it arrives in four clusters of short rises and drops, each over inside a few kilometres, with flat road running for 30 km and more between them. No rise is longer than about a kilometre. The steepest is 341 m at 5.9 percent, and the engine puts it at 0.6 percent of the bike leg. The final 47.6 km, one unbroken flat stretch into T2, holds 26 percent.
Course shape by distance
- Flat 96%
- Climbing 2%
- Descending 2%
The longest stretches
- Bike, climbing0.34 km1% of the bike
- Bike, flat47.6 km26% of the bike
- Run, flat42.2 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.
Endurance, and then the island. Aerobic endurance scores 95 on every leg, with aerobic durability and muscular endurance at 90 or above behind it. The next score is the one that makes this race its own: environmental resilience at 90, on every leg, the swim included. On most courses that dimension sits far down the list. Here only the endurance scores beat it.
The organiser gives the reasons. Highs of 31 C in 2024, 30 C in 2025 and 29 C in 2026, and lows that never dropped below 22 C, so the nights barely cool. It calls the climate warm and humid and warns of high winds on the bike. The sea was 24 C in 2025. Fueling resilience reads 85 on every leg, and a day this long in that air is why.
The climbs show up in the scores, just not near the top. On the bike, strength and force reads 49 and high-intensity capacity 37, well clear of the run's 35 and 25, and that difference is the four clusters. Ask the engine for a session built on this file and it counts eight rises of a similar shape and gives you eight efforts of a minute and a quarter in Zone 5, with four and a half minutes of easy riding after each. That is an honest picture of the climbing. It is a small part of a long day.
The bands show the rest. A Trained athlete swims 1:20:44, rides 6:16:34 at 159 W and then runs 4:16:13, for 12:03:31. The bike is 52 percent of that day. The Competitive band finishes in 10:30:05, riding 218 W from 4.15 W/kg at 75 kg and running 3:37:42. Neither band wins or loses its time on the rises.
- Aerobic endurance95
- Muscular endurance91
- Aerobic durability90
- Environmental resilience90
- Fueling resilience85
- Threshold durability80
- Technical skill77
- 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
For the athlete, every dimension scored above for the course is scored again, from their thresholds and their connected history, with a note beside each score on what it was read from. Where the course asks for more than the athlete can show, that is a gap. The gaps are then weighted by how much of the day they occupy, so a bike gap at Penghu counts for far more than a swim gap of the same size.
Nobody's data sits behind this page. Its season assumes the gaps fall where the demands are largest, and it lays out 28 weeks in 5 developmental blocks before a two-week taper. Aerobic endurance leads the first block in all three sports and fueling resilience the second. Muscular endurance then leads on the bike and run while aerobic durability leads in the water, the two swap in the fourth block, and aerobic endurance comes back to lead the last one. A member's season starts from their own numbers and will argue with 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, 52% of the day95 × 52%49
- 02Aerobic durabilityBike leg, 52% of the day92 × 52%48
- 03Muscular enduranceBike leg, 52% of the day91 × 52%47
The bike takes 52% 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 Penghu 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
- 02Bike muscular endurance, a practice block4 weeks
- 03Bike aerobic durability, a practice block6 weeks
- 04Bike aerobic endurance, a development block5 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 1Closes 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 muscular endurance
- SupportSwim aerobic durability
- SupportBike fueling resilience
- SupportRun fueling resilience
- SupportSwim fueling resilience
- Weeks 10 to 13Foundation 2Closes 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 muscular endurance
- SupportSwim aerobic durability
- Weeks 14 to 17Foundation 3Closes with a recovery week
- PriorityBike muscular endurance
- PriorityRun muscular endurance
- PrioritySwim aerobic durability
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportRun aerobic durability
- SupportSwim aerobic endurance
- SupportBike aerobic durability
- SupportSwim muscular endurance
- SupportBike fueling resilience
- SupportRun fueling resilience
- SupportSwim fueling resilience
- Weeks 18 to 21Event shaping 1Closes with a recovery week
- PriorityRun aerobic durability
- PriorityBike aerobic durability
- PrioritySwim muscular endurance
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim aerobic durability
- SupportBike fueling resilience
- SupportRun fueling resilience
- SupportSwim fueling resilience
- Weeks 22 to 25Event shaping 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 muscular endurance
- SupportSwim aerobic durability
- 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, technical skill, fueling resilience
- Bikemuscular endurance, aerobic durability, aerobic endurance, threshold durability, 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 1 · Weeks 2 to 975 to 240 min
150 to 210 min at Zone 2
BikePower, Zone 2Trains aerobic capacity - Foundation 1 · 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 1 · Weeks 2 to 935 to 120 min
90 min at Zone 2
RunPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 950 min
4 x 1.5 min at Zone 3, 6 min easy between
RunHeart rate, Zone 3Trains aerobic capacity - Foundation 1 · Weeks 2 to 945 to 51 min
4 x 8 min at Zone 2, 1 min easy between
SwimPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 947 to 81 min
3 x 1000 m at Zone 3, 0.3 min easy between
SwimPace, Zone 3Trains aerobic capacity
8× course-matched climbs
1.3 min at Zone 5, then 1.3 min at Zone 5, then 1.3 min at Zone 5, then 1.3 min at Zone 5, then 1.3 min at Zone 5, then 1.3 min at Zone 5, then 1.3 min at Zone 5, then 1.3 min at Zone 5, 4.5 min easy between
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
- 67 min
- Trains high intensity capacity
- Supports strength force
- Supports muscular endurance
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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- 4
- 5
- 6
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- 11
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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 | 1:35:16 | 6:49:16 | 5:08:08 | 13:42:40 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 1:20:44 | 6:16:34 | 4:16:13 | 12:03:31 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 1:09:49 | 5:32:34 | 3:37:42 | 10:30:05 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 1:02:33 | 5:03:26 | 3:12:35 | 9:28:34 |
Pacing plan
- 0 km0%29.2 km/h21:09
- 10.3 km3.2%15.6 km/h2:01
- 10.8 km-4.4%50.8 km/h0:42
- 11.4 km0.1%28.7 km/h1:21:51
- 50.5 km-4.6%51.6 km/h0:29
- 51 km0.4%27.2 km/h1:10
- 51.5 km5.9%10 km/h2:03
- 51.8 km2.6%17.6 km/h2:29
23 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 1:33:26.
Where it is decided
On the last 47.6 km of the bike, and then on flat roads in the heat.
By kilometre 130 the rises are behind you for good. What is left is one flat stretch to T2, a quarter of the bike leg by time, late in a long ride and open to whatever the wind is doing across the islands. Nothing on it forces a decision, which is exactly why this is where they get made badly. Riders who spent the loops chasing the clusters arrive here with less than they think. Riders who held 159 W everywhere arrive with a run.
Then the marathon. The engine reads it as one flat segment from Tonghe Road to the finish, 4:16:13 for a Trained athlete from an input of 5:06 /km threshold pace, and on a flat course in that air the only gradient is the heat. Four lap bands, each one a check on how the bike went.
Getting it wrong
The first mistake is the winter. Athletes read "rolling" and train climbs, then find the rises at Penghu are over in a few minutes each while the heat never ends. If your spring is cold, the race will be the warmest long session you have done all year, and nothing in the hills prepared you for it.
The second is the loops on Route 203. Each lap runs between two turnarounds, so any wind that carries you out toward Xiyu West Fort is a wind you ride home into. A rider who takes the fast direction at full value and the slow direction at the same power has ridden to plan. A rider who holds speed instead of power has not.
The third is the swim exit between laps. You go ashore and then back into the sea with your heart rate up. Swim the second lap at the effort of the first, not at the pace the run made you feel.
Conditions on the day
- 2026high 29 C, low 22 C
- 2025high 30 C, low 22 Cwater 24 C
- 2024high 31 C, low 24 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 1
- 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 Penghu 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
- 12:03:31
- Of the day on the bike
- 52%
- Dimensions scored per leg
- 12
- Season runway shown
- 28 wk
Questions people ask
- How hilly is the IRONMAN Penghu bike course?
- Rolling, in short bursts. The organiser calls it rolling, and the file measures 803 m of gain, but no rise is longer than about a kilometre and the steepest is 341 m at 5.9 percent. The rises come in clusters, with long flat road between them.
- How hot is IRONMAN Penghu?
- The organiser logged highs of 31 C in 2024, 30 C in 2025 and 29 C in 2026, and the low never fell below 22 C. It describes the island climate as warm and humid, with strong winds. The water read 24 C in 2025.
- What is the IRONMAN Penghu run course like?
- Flat, with 79 m of climbing in the file. You turn right onto Tonghe Road out of T2, run two laps of one section and two of another, and collect four lap bands before the finish. The route passes the Guanyinting Recreation Area and the Xiying Rainbow Bridge.
- How long should an IRONMAN Penghu training plan be?
- The illustrative season on this page runs 28 weeks, with five 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.