IRONMAN 70.3 Switzerland 2027
A clear Obersee swim, two hilly lakeside bike laps, and a run through Rapperswil's old town that climbs the castle steps they call the Stairway to Heaven.
42 weeks to race day: base season
Plenty of runway. This far out, the win is a boring, consistent base rhythm: aerobic volume, strength, technique. The structured block starts closer in; what you do now decides how high it can climb.
Building for this one? 70.3 training plan covers the sessions, the weekly shape and how the block is paced. The R.A.C.E. Framework explains why it is built that way.
Build my complete road.
Commit to the date and the work gets a shape: your countdown starts, the emails arrive in step with your build, and the app anchors a recovery-led block so the final week lands exactly on race day.
One confirmation email, then the road begins. Registering for the race itself stays with the organiser.
“The run has a set of castle steps they call the Stairway to Heaven, twice. Do some hill running off the bike before you go, your quads will thank you.”
The race
The course
The Obersee, the upper basin of Lake Zurich. Clear, buoyant, cold enough to be worth acclimatising to, and the official page does not state a lap count.
IRONMAN's route file for this leg measures 85km against a 90km course. That is too far out to publish as the route. We would rather show no map than a wrong one.
Rolling hills with demanding climbs and long descents through Swiss countryside. Not a flat course and not a mountain one either, which is the hardest kind to pace because nothing forces you to slow down.
Through the medieval streets of Rapperswil-Jona and along the lake, including the climb the race calls the stairway to heaven. A stepped climb on tired legs is a different problem from a graded one.
Not yet confirmed for this edition: lap counts on all three legs, bike elevation gain, aid station spacing, water temperature. We publish these only once they are on the official course page, so check there before you pace off anything here.
Maps © OpenStreetMap contributors. Routes from the official GPX.
Course details verified against the official IRONMAN 70.3 Switzerland course page on 13 August 2026. Courses change; the official page is always the last word.
Questions, answered
When is IRONMAN 70.3 Switzerland 2027?
What distances can I race at IRONMAN 70.3 Switzerland?
How hard is the course?
What is the swim like?
How long do I need to train for it?
How do I enter?
Read before you race
IRONMAN 70.3 Tallinn Training Guide
How Much Harder Is a Full IRONMAN Than a 70.3?
IRONMAN Kalmar Swim Preparation for Open Water and Contact
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Photograph of Rapperswil-Jona, Switzerland: Roland zh, CC BY-SA 3.0, via Wikimedia Commons. Not official race photography.
This listing is for information only. Unbroken is not affiliated with, endorsed by, or sponsored by IRONMAN 70.3 Switzerland or its organiser. Details are based on publicly available information; names are used descriptively to identify the event. For accurate, up-to-date information and to enter, always use the official event website.