Swimrun: the Ultimate Adventure Sport

Originally posted on Outdoors on SI | By Sean Langan | Last updated Jul 30, 2025 4:30 PM ET

I mistakenly assumed swimrun was a duathlon for people who dislike riding bikes. Unlike traditional, structured multi-sport events that end in an athlon, swimrun offers several unique features that make it an attractive challenge for anyone who enjoys sports, nature, and adventure.

In 2002, a couple of drunk friends made a bet, which always ends well. The goal was to cross the Stockholm archipelago, a distance of 70km, unsupported. Swim to an island, run across it, swim to the next one, repeat. The loser buys the hotel, dinner, and drinks. Not long after, ÖTILLÖ was born in 2006, an adventure race series with events in beautiful European and North American locations. ÖTILLÖ means "island to island" in Swedish.

For us, Swimrun is about experiencing nature in the purest possible way, with respect for yourself, for others, and the environment.ÖTILLÖ founders

The race has a few interesting twists. You can compete solo or with a partner. If you choose a partner, you are tied together, making it a genuine team effort. You can bring any equipment you like, but you have to keep it with you the whole time. You want to swim in a wetsuit? You have to run in it too. You want to run in sneakers? Please make sure they are waterproof.

There are several races throughout the year in varying locations, with the World Championships in Stockholm in September, paying homage to the original course where athletes traverse 24 islands between Utö and Sandhamn.

Of the total 70km, 61km are trail running, with the other 9 in the water. To officially complete the race, you must finish before dusk, which requires a good level of fitness. As the race organizers say, competitors must be very fit and very fast.

The start at Sandhamn is mythical and the finish at Utö Värdshus on Utö is like coming to Nirvana. ÖTILLÖ website

Per the website, it is also incredibly well-organized, which is important for such a unique event. The course is equipped with numerous safety boats and fueling stations, and included in the sign-up fee is lodging, ferries, dinner, and drinks, among other perks.

Anyone can do any race throughout the year, but for the World Championships, you need to qualify by accumulating points throughout the year. You're put on a qualification list and then invited. However, they do include a few wild card entries each year to keep things interesting.

If you're getting bored with traditional racing and need something more adventurous, ÖTILLÖ might be for you.

This article first appeared on Outdoors on SI and was syndicated with permission.

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