IRONMAN 70.3 · Moselle · 11 Jul 2027
How to train for IRONMAN 70.3 Luxembourg
Luxembourg sells itself as a postcard, and the postcard is accurate. You swim the Moselle from the Luxembourg bank across to the German side. You ride through vineyards past the Schengen Monument. You run the river bank through Remich in front of a crowd. The mistake is reading the profile the way the postcard invites you to: 85 percent of the course is flat by distance, so people ride it like a flat course with scenery.
It is not a flat course. It is a flat course with 41 km of hills in the middle of the bike, and all 657 m of climbing lives there, between kilometre 37 and kilometre 78. A Trained athlete's day of 5:57:51 is decided by what happens on those ramps, and by what is left for the flat 21.1 km afterwards.
By Kian Briel, race guides editor. 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 km0 m upCourse file
- Bike90.7 km657 m upCourse file
- Run21.1 km60 m upCourse file
The swim is one loop of the river, 1.9 km in water the organiser describes as low in current. You start from the bank on the Luxembourg side, cross to the German side and come back.
The bike is one loop of 90.7 km through the Moselle valley. The first 37 km are flat river road. Then the road turns away from the water and climbs into the vineyards: a 1.2 km ramp at 6 percent, a 1.5 km drag at 4.8 percent, 588 m at 7.1 percent, 1.1 km at 6.6 percent, with a run of shorter rises between them, before the road drops back to the river at kilometre 78 and stays flat for the last 13 km. Somewhere in that loop you pass the Schengen Monument, which marks the agreement signed there in 1985. You will not have much attention to spare for it.
The run is 21.1 km along the river bank through Remich, with 60 m of climbing in total. The engine reads it as one flat segment from the first metre to the last. The river bank through Remich is where the crowd is.
Course shape by distance
- Flat 85%
- Climbing 8%
- Descending 7%
Where the time goes
- Bike, flat37 km · 1:19:0337%
- Bike, climbing0.59 km · 4:322%
- Run, flat21.1 km · 2:20:26100%
Share of the Trained reference band’s leg time, from the pacing model.
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, on the bike above all. The demand model scores those two at 85 and 82 for the bike leg, with threshold capacity at 70 and threshold durability at 68 behind them, and because the bike is more than half of a Trained athlete's day, the top seven demands in the cross-leg ranking are all bike demands. The swim's top two read 85 and 80. The run's read 85 and 81. Nothing on this course rewards a sprint. Something on it punishes one.
That something is the shape of the profile. High-intensity capacity scores 58 on the bike here against 40 on the run and 40 on the swim, and the difference is the rolling middle: repeated short climbs that each ask for a minute or several above your steady power and then hand you a descent to recover on. Strength and force score 48 on the bike against 30 on the run for the same reason. The course does not want a climber. It wants a rider who can hold 3.03 W/kg at 75 kg on the flat, climb at the same power, and refuse to do more.
The bands make this concrete. A Trained athlete swims 38:09, rides 3:10:20 at 182 W and runs 1:59:22, for 5:57:51. Of that bike, roughly 41 minutes go to climbing and 2 hours 22 to flat road. The Competitive band finishes in 5:09:57, 25 minutes faster on the bike and 18 minutes faster on the run, from 4.15 W/kg at 75 kg and 4:20 /km threshold pace. It is not climbing the ramps harder that separates the two. It is holding a higher steady number for the whole three hours and still running afterwards.
Heat is the condition to respect. The organiser logged a high of 32 C in 2026 and 26 C in 2025, and for a Trained athlete the run starts nearly four hours after the gun. The water was 23 C in 2025 and 23 C in 2024, which is warm for a river.
- Aerobic endurance85
- Muscular endurance80
- Threshold capacity70
- Technical skill69
- Aerobic durability65
- Threshold durability65
- Fueling resilience55
- 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
Start from the gap, not from the course. The same twelve dimensions that score the demand above are scored on the other side from your thresholds and your connected training history, each with a note on how it was read and how far to trust it. Where the course scores higher than you can show, that is a gap, and the gaps are ranked by how much of the day they fill. On a course where the bike is more than half of the day, a bike gap outranks a swim gap of the same size by a wide margin.
There is no athlete on this page, so the season below cannot know your gaps. It takes the simplest assumption instead: that they fall where the demands are largest. From that it lays out 24 weeks in 5 developmental blocks, each led by one dimension per sport, and it places the most race-like work nearest the race. A member's season starts from their own numbers and will disagree with this one in its priorities and in its load. That disagreement is the product.
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, 55% of the day85 × 55%47
- 02Muscular enduranceBike leg, 55% of the day82 × 55%45
- 03Threshold capacityBike leg, 55% of the day70 × 55%38
The bike takes 55% 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 Luxembourg 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
- SupportSwim technical skill
- SupportBike threshold durability
- SupportRun aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PrioritySwim technical skill
- PriorityBike threshold durability
- PriorityRun 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
- SupportSwim technical skill
- SupportBike threshold durability
- SupportRun 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
- SupportSwim technical skill
- SupportBike threshold durability
- SupportRun 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
- SupportSwim technical skill
- SupportBike threshold durability
- SupportRun 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, technical skill
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
Vetted library structures that train each block's lead at its native intensity, plus the one session compiled from this course's own geometry.
- Foundation 1 · Weeks 2 to 590 min
70 min at Zone 2
BikePower, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 590 min
66 min at Zone 2
BikeHeart rate, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 560 min
40 min at Zone 2
RunHeart rate, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 560 min
40 min at Zone 2
RunHeart rate, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 545 min
30 min at Zone 2
SwimPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 554 min
4 x 8 min at Zone 2, 1 min easy between
SwimPace, Zone 2Trains aerobic capacity
12× rolling-course surges
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, 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, 3.5 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
- 79 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 | 0:45:01 | 3:30:48 | 2:23:34 | 6:49:23 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:09 | 3:10:20 | 1:59:22 | 5:57:51 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:32:59 | 2:45:32 | 1:41:26 | 5:09:57 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:29:33 | 2:31:11 | 1:29:44 | 4:40:28 |
Pacing plan
- 0 km0%30.8 km/h1:12:00
- 37 km6%11.2 km/h6:22
- 38.1 km-3.2%46.3 km/h1:31
- 39.3 km1.4%24.2 km/h0:43
- 39.6 km5%12.9 km/h2:07
- 40.1 km2.6%19.4 km/h0:29
- 40.2 km4.8%13.3 km/h6:50
- 41.7 km1.8%22.5 km/h1:40
42 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 47:54.
Where it is decided
On the ramps, by what you do not do on them.
Each climb in the middle of the bike is short. The 6 percent ramp at kilometre 37 takes a Trained athlete a little over six minutes. The 7.1 percent at kilometre 44 takes under five. Every one of them feels like it deserves a surge, because you can see the top, the rider ahead is out of the saddle, and a surge costs nothing you can feel at the time. The engine compiled this bike into a workout of twelve surges of a minute and a quarter each with three and a half minutes of easy riding between them, and that is the honest shape of the leg: a repeated question, asked a dozen times in 41 km, to which the right answer is the same power you held on the river road.
Then the road drops to the Moselle at kilometre 78 and stays flat for 13 km into Remich. This is where the surges are paid for. A rider who answered every ramp with a surge arrives here with the run already spent, and the flat 21.1 km along the river, which the engine scores as aerobic endurance and muscular endurance and little else, becomes the longest run of their year. A rider who held 182 W everywhere gets off the bike with the run intact and finds the crowd useful instead of cruel.
Getting it wrong
The first mistake happens before any climb. The opening 37 km are flat, the field is still together, and the road along the river is fast. Riders take their best 40 km power out of the swim and spend it here, so they reach the first ramp at kilometre 37 already at threshold. The engine puts more than a third of the bike leg on that first flat stretch. It is the largest single block of time in the race, and it is where the day's power is set, for better or worse.
The second is the ramps, and they have their own section above. One more line on them: nobody wins Luxembourg on a climb, and plenty lose it on one.
The third is the heat on the run. In 2026 the day reached 32 C, the run is flat along the water, and a Trained athlete starts it nearly four hours in. Runners who paced the bike well still lose the run here, by starting at the pace they trained for in spring rather than the pace the day allows. The river bank through Remich is loud from the first kilometre. Run to your plan, not to the noise.
Conditions on the day
- 2026high 32 C, low 17 C
- 2025high 26 C, low 13 Cwater 23 C
- 2024high 24 C, low 18 Cwater 23 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 Luxembourg 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
- 5:57:51
- Of the day on the bike
- 55%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- How hilly is the IRONMAN 70.3 Luxembourg bike course?
- Rolling, not mountainous. The one-loop 90 km course climbs 657 m in total, and all of it sits between kilometre 37 and kilometre 78. The steepest sustained ramp is 588 m at 7.1 percent. The first 37 km and the last 13 km are flat river road.
- What is the water temperature for the swim in the Moselle?
- The organiser records 23 C in both 2025 and 2024. That is warm for a river swim. The organiser publishes the wetsuit decision in the athlete guide, not on the course page, so check it in race week.
- Is the IRONMAN 70.3 Luxembourg run course flat?
- Yes. The 21.1 km run climbs 60 m in total and follows the river bank through Remich. The engine reads it as one flat segment from the first metre to the last.
- How long is the season on this page?
- The illustrative season is laid out on 24 weeks, with five developmental blocks and a two-week taper. Your own season starts from your numbers and can be longer.
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.