IRONMAN 70.3 · Rapperswil-Jona · 6 Jun 2027
How to train for IRONMAN 70.3 Switzerland
People come to Rapperswil-Jona expecting the climbs to be the test. They are right about the climbs and wrong about the test. Twice the road leaves the lake and rises more than 300 m, and twice the effort that counts comes after the steep part, on the long drags where the gradient eases but never quite lets go.
The engine read this bike file and wrote one session for it: ten climbs of three and a half minutes in Zone 5, each running straight into a minute in Zone 4 with no easy spin between. That is the whole course in one workout. A Trained athlete's 5:58:53 is decided by what they do in that minute after each ramp, ten times over two loops.
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.
- Swim1.91 km0 m upCourse file
- Bike85.1 km957 m upCourse file
- Run20.9 km120 m upCourse file
The swim is in the Obersee, water the organiser calls crystal-clear and buoyant, logged at 17 C in 2026 and 14 C two years earlier. It is 1.9 km long. Transition is about 100 m from the swim exit.
You mount on Oberseestrasse and ride two loops of what the organiser describes as rolling hills and demanding climbs with rewarding descents. The first 10 km are flat. Then the road climbs from the lake at 408 m to its high point of 744 m near kilometre 19, mostly in ramps between 5 and 9 percent with short easier stretches between them. The descent that follows runs back down to lake level, and 18.7 km of flat road carry you to the second loop. It repeats the pattern, topping out at 736 m near kilometre 61, and the last 10 km back to Oberseestrasse are flat again.
The run leaves transition towards the Strandweg. The organiser's route goes through the medieval streets of Rapperswil-Jona, along the lakeside and up the famous stairway to heaven before the finish, and the cut-off list shows it is two laps. The organiser tags it Rolling. The file is gentler than the word: 120 m over 20.9 km, with its one real rise, 198 m at 5.1 percent, a little over 2 km from the end.
Course shape by distance
- Flat 79%
- Climbing 10%
- Descending 11%
The longest stretches
- Bike, climbing0.33 km2% of the bike
- Run, flat8.41 km40% of the run
- Run, flat9.82 km47% 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.
On the bike, aerobic endurance first and muscular endurance close behind: 85 and 83. Threshold durability comes next at 71, above threshold capacity at 70, which is the course telling you it wants a hard effort you can repeat rather than one you can hit once. Because the bike fills 54 percent of a Trained athlete's day, the eight largest demands on the course all belong to it. The run's pair reads 85 and 81, the swim's 85 and 80.
Two scores make this bike its own thing. Strength and force reads 53, from ramps like the 1.4 km at 7 percent near kilometre 16 and its twin at 6.8 percent on the second loop. High-intensity capacity reads 58, from the way each ramp arrives: steep, short enough to attack, and followed by a false flat that punishes the attack. On the run strength and force reads 38 and high-intensity capacity 42, so it asks for neither.
The reference bands put a clock on it. The Trained athlete swims 38:22, rides 3:12:01 at 182 W from an input of 3.03 W/kg at 75 kg, and runs 1:58:30. Roughly a third of that ride goes on climbing, on about an eighth of the road. The Competitive band finishes in 5:06:38 from 4.15 W/kg at 75 kg, riding 2:42:45 and running 1:40:42. More of the gap between those two bands is made on the climbs than anywhere else, because that is where the watts buy time, but it is made by holding 249 W up them, not by surging.
Conditions have been kind. The organiser logged highs of 26 C in 2024, 24 C in 2025 and 23 C in 2026. The low in 2026 was 9 C, and in 2024 the lake was only 14 C, so the start can be cold even when the afternoon is not.
- Aerobic endurance85
- Muscular endurance80
- Threshold capacity70
- Aerobic durability65
- Threshold durability65
- Technical skill59
- 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
Every Nymiva reading scores twelve dimensions, once for the course from the organiser's files and once for the athlete from their thresholds and connected training history. Each athlete score says what it was read from and how much weight it bears. A gap exists only where the course asks for more than the athlete can show, and it is weighted by how much of race day it covers. The bike covers 54 percent here and the swim 11 percent, so the ranking leans hard towards the bike.
This page has no athlete behind it. Its season therefore assumes the gaps sit where the demands are largest, and lays out 24 weeks in 5 developmental blocks before a two-week taper. Aerobic endurance leads the first block in all three sports. In the second, the bike moves to threshold capacity, the run to threshold durability and the swim to aerobic durability. The third swaps the two threshold dimensions between bike and run, with the swim on threshold capacity. Muscular endurance leads the fourth, and aerobic endurance leads again in the fifth. A member's own season is ordered by their numbers, not by this assumption.
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, 54% of the day85 × 54%46
- 02Muscular enduranceBike leg, 54% of the day83 × 54%44
- 03Threshold durabilityBike leg, 54% of the day71 × 54%38
The bike takes 54% 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 Switzerland 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 durability
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityBike threshold capacity
- 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 durability
- SupportRun threshold capacity
- SupportSwim threshold capacity
- Weeks 10 to 13Foundation 3Closes with a recovery week
- PriorityBike threshold durability
- 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 capacity
- 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 durability
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- 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 durability
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- 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
10× climb-to-false-flat repeats
3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, then 3.5 min at Zone 5, then 1 min at Zone 4, 5.8 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
- 122 min
- Trains muscular endurance
- Supports strength force
- Supports high intensity capacity
- Supports threshold durability
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 | 0:45:17 | 3:35:22 | 2:22:31 | 6:53:10 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:22 | 3:12:01 | 1:58:30 | 5:58:53 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:33:11 | 2:42:45 | 1:40:42 | 5:06:38 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:29:44 | 2:27:10 | 1:29:04 | 4:35:58 |
Pacing plan
- 0 km0%30.8 km/h19:44
- 10.1 km8.7%8.1 km/h7:23
- 11.1 km0.3%29.3 km/h1:34
- 11.9 km-8.2%66.3 km/h0:17
- 12.2 km1.1%25.5 km/h6:18
- 14.9 km8.9%8 km/h3:03
- 15.3 km1.5%23.7 km/h1:02
- 15.7 km7%9.8 km/h8:42
43 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 52:15.
Where it is decided
In the minute after each ramp.
The steepest pitch on the course, 327 m at 10.4 percent near kilometre 57, is the one you will remember, and it costs a Trained rider 1.6 percent of the bike leg. It is not the problem. The problem is the ground right after the steep sections, where the gradient drops to 2 or 3 percent and the road still climbs. Look at the ground around that steepest pitch. After it the file carries 538 m at 2.2 percent, then 1.3 km at 7.2 percent, then 351 m at 2.8 percent and 1.7 km at 4.8 percent. A rider who crested the ramp above threshold now has to keep pushing on legs that want to recover, and there is no descent to let them.
That is why the engine's session is built the way it is, and why the second loop matters more than the first. The 18.7 km of flat between the loops feels like a rest. It is only a pause, and the second climb block starts at kilometre 52 whether you are ready or not.
Then the run makes its case. Two long flat stretches of 8.4 km and 9.8 km hold 40 and 47 percent of the run leg. From an input of 5:06 /km threshold pace, the Trained reference runs 1:58:30. That pace survives the lakeside only if the bike was ridden at its intended power on both loops.
Getting it wrong
Treating the first loop as a warm-up for the second. The legs are fresh at kilometre 10, the ramps look short, and the high point comes quickly. Ride it at the power you plan for the second loop, or the second loop will choose a lower one for you.
Resting on the false flats. Every rider knows to ease off at the top of a steep ramp, and on this course that instinct costs the most time, because the top of the ramp is not the top of the climb. The engine's session pairs each climb with a minute in Zone 4 for exactly this reason.
Coasting the descents. The road drops back to the lake on each loop, and a rider who took too much out of the climbs tends to coast every descent and still arrive at Oberseestrasse tired. The run then goes towards the Strandweg with the lake beside it and no hill to blame, and that is where the bike is paid for.
Conditions on the day
- 2026high 23 C, low 9 Cwater 17 C
- 2025high 24 C, low 15 Cwater 18 C
- 2024high 26 C, low 13 Cwater 14 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 Switzerland 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
- 5:58:53
- Of the day on the bike
- 54%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- How hilly is the IRONMAN 70.3 Switzerland bike course?
- The organiser tags it Hilly, and the file climbs 957 m over 85.1 km in two loops. Each loop rises from the lake to a high point above 730 m, reaching 744 m on the first. The steepest sustained ramp is 327 m at 10.4 percent, near kilometre 57.
- What water temperature should I expect in the Obersee?
- The organiser logged 17 C in 2026, 18 C in 2025 and 14 C in 2024. The wetsuit rule is not on the course page, so check it in race week.
- Is the IRONMAN 70.3 Switzerland run hilly?
- The organiser tags it Rolling. The file climbs 120 m over 20.9 km, and its only real rise is 198 m at 5.1 percent, a little over 2 km from the end. The route runs through the medieval streets of Rapperswil-Jona, along the lakeside and up the stairway to heaven.
- How far is it from the swim exit to transition?
- About 100 m. The bike starts from the mount line on Oberseestrasse, you come back in from Oberseestrasse after two loops, and the run leaves transition towards the Strandweg.
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.