IRONMAN Switzerland Thun, Thun, Bernese Oberland, Switzerland

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IRONMAN Switzerland Thun 2027

Thun, Bernese Oberland, Switzerland

4 July 2027 Triathlon Full (iron distance) AlpineStunningHilly

A glacial lake swim under the Bernese Alps, a climbing bike leg on immaculate Swiss roads, and a run along the Aare into Thun.

Terrain

Road

Alpine foothills, immaculate roads

Elevation

Hilly

Bernese Oberland does not do flat

Swim

Lake

Lake Thun, glacial and clear

Wetsuit

Wetsuit-legal

usually 18-21°C

Region

Switzerland

Thun, Bernese Oberland, Switzerland

Your runway

46 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.

Recover

Fix the nervous system first. Sleep, HRV, and the noise out.

Align

Fit the plan to your actual life, not the one you wish you had.

Condition

Minimum effective dose. The right sessions, done fresh.

Execute

Race-week protocol, pacing, contingency. Nothing new on race day.

Build my complete road Predict your finish time

Building for this one? Ironman 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.

Road to Race

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.

Already have the app, or want it? The app takes this race and builds the block around it.

“Alpine scenery, perfect tarmac and a course that climbs. Respect the descents as much as the climbs, because tired bike handling at altitude is where days go wrong.”

Abraham Spring: founder, Unbroken

The race

Thun trades speed for scenery and gets a good deal. The swim is clear cold glacial water in Lake Thun with the Eiger, Monch and Jungfrau on the skyline. The bike climbs through the Bernese Oberland foothills on the kind of tarmac that makes British riders emotional. The run follows the Aare into the old town. This is a race you enter for the day itself.

The course

Swim3.8 km

Lap count not published

Swim course map for IRONMAN Switzerland Thun: the official route drawn on an OpenStreetMap basemap

Clear cold glacial water in Lake Thun, with the Bernese Alps on the skyline. The official page describes the swim without stating a lap count, so we do not state one either. Swim exit is a flat 200m run on asphalt into transition.

Bike180.2 km

2 laps

Bike course map for IRONMAN Switzerland Thun: the official route drawn on an OpenStreetMap basemap

Two loops climbing through the Bernese Oberland on immaculate Swiss tarmac, with steep sections and long descents. The lap count is not in the bike description; it comes from the transition notes, which refer to returning from the 2-loop bike course.

Run42.2 km

Lap count not published

Run course map for IRONMAN Switzerland Thun: the official route drawn on an OpenStreetMap basemap

Across Thun's bridges and through the old town beside the Aare. The page does not state a total lap count, but the final cut-off sits at the start of the third lap, so it is at least three.

Bike elevation, drawn from the official GPX. The vertical scale is held at a fixed 200m so a flat course looks flat rather than being stretched to fill the chart.

Run elevation, drawn from the official GPX. The vertical scale is held at a fixed 200m so a flat course looks flat rather than being stretched to fill the chart.

Cut-offsSwim 2h20 · Swim + T1 + Bike 10h30 · Overall 17h00. Intermediate: 13:30 at the start of the second bike lap, 22:00 at the start of the third run lap

T1The soccer pitch at the Lachen Stadion. A flat 200m asphalt run from the swim exit, water station on the left, then the bag racking area. Blue and red bags hang on the same rack, blue on the top bar and red on the bottom.

T2The same area in reverse. Rerack the bike, take the running gear from the red bag, hang the red bag back on the hook, then out through the gate you came in by after the swim.

In transitionToilets, changing tents, benches, bike mechanic, bike pumps, lost chip service, spare transition bags, bottle fill station. Water station on the swim-to-bike side only.

Typical race day12–27°C air · 17°C water

Not yet confirmed for this edition: swim lap count, run lap count, bike elevation gain, water temperature history. 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 Switzerland Thun course page on 14 August 2026. Courses change; the official page is always the last word.

Questions, answered

When is IRONMAN Switzerland Thun 2027?

IRONMAN Switzerland Thun takes place on 4 July 2027.

What distances can I race at IRONMAN Switzerland Thun?

Full (iron distance). Pick the distance that fits your training runway, not your ego: the right distance is the one you can arrive at fresh.

How hard is the course?

Road terrain, hilly profile. Bernese Oberland does not do flat

What is the swim like?

Lake Thun, glacial and clear. Wetsuit-legal, usually 18-21°C. Practise open water before race week, not during it.

How long do I need to train for it?

Race day is 4 July 2027. For the full distance, a proper recovery-led build wants about 20 weeks, which means starting around 14 February 2027. Later starts still work: the block compresses honestly rather than pretending, and it always anchors to the exact race date.

How do I enter?

Entries are handled by the organiser. Use the Register button above: it goes straight to the official site.

Read before you race

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IRONMAN Copenhagen Weather, Nutrition and Clothing Strategy

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IRONMAN Copenhagen Training Timeline: From Base to Race Week

Build a Copenhagen-specific training runway around swim confidence, sustained aero durability, controlled pacing and a four-lap marathon.

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Photograph of Thun, Bernese Oberland, Switzerland: Carsten Steger, CC BY-SA 4.0, via Wikimedia Commons. Not official race photography.

This listing is for information only. Unbroken is not affiliated with, endorsed by, or sponsored by IRONMAN Switzerland Thun 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.

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