IRONMAN Copenhagen

The course

You start at Amager Strandpark in a rolling start, seven groups released from 07:00 by predicted swim time, six swimmers every five seconds. The swim is a single counter-clockwise loop of 3.8 km in the protected lagoon, which the organiser describes as calm with hardly any waves or current. A wetsuit is mandatory under 16 °C, optional up to 24.5 °C and banned above that; the swim cut-off is 2 h 20 min from your own start.

The bike is 180 km in two loops of North Zealand after you leave Amager, with 1,100 m of climbing, long straight roads, coastal stretches along the so-called Danish Riviera and some rolling hills. The athlete guide warns of flint stones on the roads and advises a solid racing tyre. Aid stations are at 21, 33, 66, 100, 133 and 164 km, so you pass the same stations on each loop. Cut-offs on the bike are at north Taarbæk (21.6 km), the start of the second lap at Skodsborgvej (93.1 km, last rider must start by 14:00) and Dageløkkevej (143.5 km, 16:00), and 9 h 30 min for swim plus bike overall. You finish the bike at T2 on Kongens Nytorv.

The run is four loops of the city centre from Kongens Nytorv and Nyhavn to a finish at Christiansborg Palace Square; you pass the Little Mermaid and the King's castle four times. The guide calls it relatively flat with varying surfaces. Aid stations (water, electrolyte drink, cola, energy drink, Maurten gels and bars, fruit and salty snacks) are roughly every 1.5 to 2 km, and the finish is open until 23:30 with a whole-course limit of 15 h 45 min after the last swimmer starts. Spectators line much of it.

How to enter

Entry is first come, first served and the race has sold out faster each year: it took 92 days in 2025, 46 hours for 2026 and about one hour for 2027, when more than 3,000 numbers went in August 2026 during race week. The organiser sells entries for the following year partly through on-site registration in race week, with extra windows on Thursday to Saturday and Monday, and the race page has a 'Notify me' link for later releases. For 2028 expect the same pattern, so be signed up for the organiser's updates and have your payment ready.

The race is a Kona qualifier. Age-group winners get an automatic slot to the 2027 IRONMAN World Championship and the rest are offered by age-graded performance in a roll-down ceremony on the Monday, where you must be present in person with photo ID and a credit card. The fee for a Kona slot in 2026 was USD 1,834. You also need a triathlon licence (shown at registration), and the organiser has an official bike rental and transport partner listed on its pre-race page. We could not find the entry fee on any page that was open to us, and the organiser publishes it only during registration.

How to train for it

Train your swim in a group

The rolling start releases six swimmers every five seconds in groups by predicted time, so you will be in company throughout the 3.8 km. Practise open-water swimming with others, and give a realistic swim estimate at registration because it sets your start group. The cut-off is 2 h 20 min from your own start.

Prepare for a rolling, windy bike

There is 1,100 m of climbing on 180 km, long straights with exposure to wind and no steep hills. Long rides of 4 to 6 hours on rolling roads with steady power, and practice with aero position held for long periods, are more useful than hill repeats.

Rehearse flint and punctures

The guide warns of flint stones on the bike course and says you must carry your own tubes, tyres and tools; mechanical support is on a first come, first served basis and there can be a wait. Practise a quick tube change.

Run the loops in your head

The run is four city loops with an aid station roughly every 1.5 to 2 km and a personal needs bag at 1.6, 11.5, 21.4, 31.3 and 41.1 km. Break the marathon into four loops of about 10.5 km and practise eating every 30 to 40 minutes on the run, not only the bike.

Plan for the median, not the winner

The median finisher took 11 h 16 min in 2026, so the second half of the run is in the evening on tired legs. Train brick sessions (bike then run) and long days, and have your pacing plan inside the 9 h 30 min swim-plus-bike limit and the 15 h 45 min whole-race limit.

What you need

• Triathlon licence or day licence to show at registration, photo ID and the emailed QR code
• Timing chip, worn on the left ankle from bike check-in to bike check-out (the organiser lends it to you and bills you if you lose it)
• Wetsuit (mandatory below 16 °C water, banned above 24.5 °C), not thicker than 5 mm and without forearm reinforcement, and a swim suit that is 100% textile for non-wetsuit swims
• Helmet, a bike in good order, and tubes, tyres and tools for self-repair; bib on the back for the bike and the front for the run
• Three transition bags handed in the day before (blue bike bag, red run bag) plus a street-wear bag dropped at T1 by 07:15 and collected after the finish
• Optional personal needs bags (one for the bike and one for the run), dropped before 06:45 on race morning; self-service from friends is not allowed
• Warm dry clothes for the evening, since the finish is open until 23:30

Getting there and staying

Copenhagen Airport is the nearest airport. The swim start and T1 are at Amager Strandpark (Jollevej 1); the guide recommends the metro on race morning, to the Amager Strandpark or Femøren stations on the M2 line. The finish and T2 are in the city centre where the guide says parking is difficult and the metro stops at both. The roads around Amager Strandpark close at 06:00 on race morning and reopen after 11:00. An event ticket for 12 hours of bus, train and metro on race day cost 30 DKK or 60 DKK in 2026, bought in the Rejsebillet app.

Registration and the IRONMAN Village are at Amager Strandpark from Thursday to Saturday (in 2026: Thursday 10:00 to 18:00, Friday 10:00 to 16:00, Saturday 10:00 to 14:00; you must register by 14:00 on Saturday). Bike and bag check-in is on Saturday 11:00 to 18:00. The race briefing is Friday in English and Danish. Book a bed early: with more than 2,500 athletes plus families, central Copenhagen fills.

On race day transition opens at 05:00, the swim starts at 07:00 to 07:45 and the finish is open from 14:45 to 23:30 at Christiansborg Palace Square. Collect your bike and bags from T2 between 16:00 and 23:45. The awards ceremony and Kona slot allocation is on the Monday at 10:00.

Where to find out more

• IRONMAN Copenhagen race page (opens in a new tab): Registration status, race facts and links to the schedule and athlete guide.
• Event schedule (opens in a new tab): The week's programme: registration, briefings, bike check-in, race day and awards.
• Pre-race info and athlete guide (opens in a new tab): The 2026 athlete guide and first-timer guide as PDFs, plus bike rental and transport partners.
• Kona qualification and slot allocation (opens in a new tab): How age-group slots and the roll-down work.
• Results 2026 (opens in a new tab): Full 2026 results with splits; used for the median time on this page.