IRONMAN 70.3 · Versailles · 11 Oct 2026
How to train for IRONMAN 70.3 Versailles
Versailles is sold on its setting, and the setting earns it. You swim the Grand Canal, rack your bike beside the château and finish on the Avenue de Paris with the palace behind you. Between those postcards sits a bike course the organiser describes by its two famous climbs, and that is where most people's preparation goes wrong. They train for the Côte de la Vacheresse and the 17 Tournants. The course asks for something else.
717 m of climbing, yes. But 88 percent of the whole course is flat by distance, and the steepest ramp in the file is neither of the named climbs. It is 439 m at 7.5 percent, and it arrives past kilometre 70, in the last fifth of the bike.
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.
- Swim1.9 kmDistance only
- Bike87.7 km717 m upCourse file
- Run21.1 km187 m upCourse file
The swim is one loop of 1.9 km in the calm water of the Grand Canal of the château de Versailles. Out of the water you head for transition on Allée de la Reine, collect the blue bag, change on the benches or in the tents, and hang the bag back on its numbered hook before you reach the bike.
The organiser calls the bike 90 km, and the file it publishes measures 87.7 km. It goes out into the Chevreuse Valley. The Côte de la Vacheresse is 1.6 km at 4.6 percent. The roads around the Abbaye des Vaux de Cernay run for 6 km, and the 17 Tournants, 1.3 km at 5.7 percent, is the hill local riders come to ride. The organiser's own summary is honest: punchy elevation changes alternating with fast, flowing sections.
Three loops make up the run, 21.1 km with 187 m of gain. It follows the Pièce d'Eau des Suisses with the château in view, crosses the Potager du Roi, then works through the historic streets of the town, through the École Spéciale d'Architecture and past the Salle du Jeu de Paume, before the finish on the Avenue de Paris.
The profile tells you where the time actually goes. The single biggest block of the bike is a flat 9.5 km stretch from kilometre 26, and it holds 10 percent of the leg on its own. The steepest climb holds 1.7 percent. The run the engine reads as one flat segment.
Course shape by distance
- Flat 88%
- Climbing 6%
- Descending 6%
The longest stretches
- Bike, flat9.52 km10% of the bike
- Bike, climbing0.44 km2% of the bike
- Run, flat21 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.
Aerobic endurance and muscular endurance lead on every leg, and on the bike they are joined by threshold capacity, threshold durability and aerobic durability. The bike fills 52 percent of a Trained day, so the six largest demands on the whole course are all bike demands, and the run's aerobic endurance only arrives seventh.
The sixth is the interesting one. High-intensity capacity scores far higher on the bike than on either other leg, and strength scores higher there too. Both come from the same place: a file that tips up fifteen times and down seventeen, mostly in short pitches, each of which invites a minute of effort above the power you can hold all day. Ask the engine for a workout built from this bike and it returns twelve 45-second efforts in Zone 5 separated by six minutes of easy spinning. That is the rhythm of the Chevreuse Valley as the file describes it.
On the run the picture turns. Technical skill scores higher on this run than on the bike, a reading of the corners the loop takes through the town.
Now put the bands beside it. A Trained athlete swims 38:12, rides 3:04:08 at 182 W and runs 1:59:27, for 5:51:47. The Competitive band, from 4.15 W/kg at 75 kg, rides 2:41:33 at 249 W and runs 1:41:30 for 5:06:06. What separates them is a higher steady number held through every pitch, not a harder attack on any single one.
The weather is a lottery in October. The organiser logged a high of 25 C in 2023 and then 14 C with a low of 5 C in 2024. In 2025 the day topped out at 18 C.
- Aerobic endurance85
- Muscular endurance80
- Threshold capacity70
- Aerobic durability65
- Threshold durability65
- Fueling resilience55
- Technical skill55
- High-intensity capacity40
- Anaerobic capacity25
- Strength / force20
- Environmental resilience15
- Sprint power5
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
On one side of every Nymiva season sits the course, scored from its file. The other side is you, scored on the same twelve dimensions from your thresholds and your connected training history, each score marked with what it came from and how firm it is. A dimension becomes a gap only when the course asks more of it than you can show, and every gap is weighted by how much of race day it occupies. With the bike at more than half of a Trained day and the swim at 11 percent, a modest bike gap outranks a large swim gap.
This page carries no one's data. Its season therefore assumes the simplest thing, that your gaps sit exactly where Versailles demands the most, and spreads 24 weeks across 5 developmental blocks and a taper. Aerobic endurance leads the first block in every sport. Threshold durability then takes the bike and run while the swim works on aerobic durability, and threshold capacity leads all three in the block after. Muscular endurance comes next, and aerobic endurance returns to lead the last block before the taper. A member's season begins 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 day85 × 52%45
- 02Muscular enduranceBike leg, 52% of the day82 × 52%43
- 03Threshold capacityBike leg, 52% of the day70 × 52%37
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 70.3 Versailles 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 muscular endurance, a practice block4 weeks
- 02Run aerobic endurance, a development block4 weeks
- 03Bike muscular endurance, a practice block4 weeks
- 04Bike aerobic endurance, a development block4 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 5Foundation 1Closes with a recovery week
- PriorityBike aerobic endurance
- PriorityRun aerobic endurance
- PrioritySwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike threshold durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityBike threshold durability
- PriorityRun threshold durability
- PrioritySwim aerobic durability
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- Weeks 10 to 13Foundation 3Closes with a recovery week
- PriorityBike threshold capacity
- PriorityRun threshold capacity
- PrioritySwim threshold capacity
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 14 to 17Event shaping 1Closes with a recovery week
- PriorityBike muscular endurance
- PriorityRun muscular endurance
- PrioritySwim muscular endurance
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike threshold durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 18 to 21Event shaping 2Closes with a recovery week
- PriorityBike aerobic endurance
- PriorityRun aerobic endurance
- PrioritySwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike threshold durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 22 to 23PeakPeak
The taper. Load comes down toward the race, content stays specific.
- Week 24RaceRace
Race week.
Held at maintenance between blocks
- Runmuscular endurance, aerobic endurance, aerobic durability, threshold capacity, threshold durability
- Bikemuscular endurance, aerobic endurance, aerobic durability, threshold capacity, threshold durability
- Swimaerobic endurance, aerobic durability, threshold capacity, threshold durability, muscular endurance
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 575 to 240 min
150 to 210 min at Zone 2
BikePower, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 540 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 535 to 120 min
90 min at Zone 2
RunPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 550 min
4 x 1.5 min at Zone 3, 6 min easy between
RunHeart rate, Zone 3Trains aerobic capacity - Foundation 1 · Weeks 2 to 545 to 51 min
4 x 8 min at Zone 2, 1 min easy between
SwimPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 547 to 81 min
3 x 1000 m at Zone 3, 0.3 min easy between
SwimPace, Zone 3Trains aerobic capacity
12× rolling-course surges
0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, 6 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
- 100 min
- Trains threshold durability
- Supports muscular endurance
- Supports high intensity capacity
24 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.
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 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 | 0:45:05 | 3:23:52 | 2:23:39 | 6:42:36 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:12 | 3:04:08 | 1:59:27 | 5:51:47 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:33:03 | 2:41:33 | 1:41:30 | 5:06:06 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:29:36 | 2:27:32 | 1:29:47 | 4:36:55 |
Pacing plan
- 0 km0.9%26.5 km/h6:29
- 2.86 km4.7%13.5 km/h3:37
- 3.68 km-1%35.8 km/h2:54
- 5.4 km-4.5%52 km/h0:41
- 6 km-3%45.4 km/h0:22
- 6.27 km6.1%11 km/h3:13
- 6.86 km-0.1%31.3 km/h15:09
- 14.8 km-3.6%48.1 km/h0:13
59 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 45:41.
Where it is decided
In the eight kilometres from kilometre 68 to kilometre 76.
Up to there the bike has been a series of small questions, and a disciplined rider has answered each one at 182 W. Then the file drops for more than a kilometre, and the road kicks straight back up: 439 m at 7.5 percent, a breath of flat, 219 m at 6.4 percent, and under five kilometres later 501 m at 5.8 percent. The two steepest pitches on the course sit back to back in that cluster, near the end of the bike, and they meet you on legs that have already done most of the day's climbing. A rider who has been surging on every ramp since the valley has nothing left to climb them at a sensible power, so they climb them at a silly one.
After that come 7.7 km of flat road, a short descent and 3.4 km more of flat to finish the bike, and those flat kilometres are where the invoice is written. The run is 1:59:27 for a Trained athlete from an input of 5:06 /km threshold pace. Arrive at transition having held your number through that final cluster and those three loops are a run. Arrive having fought it and they are a very long walk past the Potager du Roi.
Getting it wrong
The first mistake is training for the wrong climbs. Riders read the organiser's page, see two famous names, and spend the spring doing long, steady climbing. The Côte de la Vacheresse and the 17 Tournants are both under two kilometres. The file's hardest work comes in pitches of a few hundred metres, and strength scores a long way behind aerobic endurance on this bike.
The second is the flat 9.5 km from kilometre 26. It comes right after the first run of climbs and it holds more bike time than any other single stretch of road. Riders who lost time on the early ramps try to buy it back here, above their number, and set the power for the whole day in the process.
The third is believing the word flat on the run. 187 m spread over three loops is small, but the loop goes through the town rather than along a straight, and the historic streets past the Salle du Jeu de Paume keep asking you to slow down and get going again. Pace the first loop to the château view and the third loop will tell you about it.
Conditions on the day
- 2025high 18 C, low 11 C
- 2024high 14 C, low 5 C
- 2023high 25 C, low 10 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 70.3 Versailles 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
- 5:51:47
- Of the day on the bike
- 52%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- How hilly is the IRONMAN 70.3 Versailles bike course?
- Rolling. The file the organiser publishes climbs 717 m, and 88 percent of the whole course is flat by distance. The organiser names two climbs in the Chevreuse Valley, the Côte de la Vacheresse at 1.6 km and 4.6 percent and the 17 Tournants at 1.3 km and 5.7 percent. The steepest sustained ramp in the file is shorter and steeper, 439 m at 7.5 percent past kilometre 70.
- Where is the swim at IRONMAN 70.3 Versailles?
- One loop of 1.9 km in the calm water of the Grand Canal of the château de Versailles. Transition sits on Allée de la Reine at the château. The organiser's historical table carries no water temperatures, so check the wetsuit decision in race week.
- Is the IRONMAN 70.3 Versailles run flat?
- The organiser calls it flat, and the file measures 187 m of gain over three loops of the town. It runs beside the Pièce d'Eau des Suisses, through the Potager du Roi and the historic streets, and finishes on the Avenue de Paris with the château behind you.
- What is the weather like for the race in October?
- It swings. The organiser records a high of 25 C in 2023, then a high of only 14 C and a low of 5 C in 2024, and a high of 18 C in 2025. Pack for both.
Course data from the organiser’s published files, analysed 23 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 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.