Tim Marklowski wants to challenge the image of the big outdoor adventures – and himself. During 2025, he has completed several extreme tours with minimal CO₂ emissions.

From dream to expedition

The idea first emerged when Tim Marklowski and his wife borrowed a small sailboat from a friend and spent several months at sea. While sailing between Corsica and Sardinia, Marklowski wondered: “Has anyone ever swum between the two islands?”

After a bit of research, he learned that someone had. But the islands also feature two of Europe’s toughest trails – Corsica’s GR20 and Sardinia’s Selvaggio Blu – and according to his findings, no one had ever combined the two-in-one human powered triathlon.

“I knew I could manage the cycling, trail running, and hiking – but I had zero experience in open-ocean swimming,” Marklowski says.

Credit: Sandra Boschert

All-terrain ambitions

He describes his childhood dream of becoming an “all-terrain animal,” one able to move fluidly through any environment. In early 2025, Marklowski began intense swim training while taking on a series of demanding mountain missions.

“I wanted to challenge the idea that great adventures only exist in faraway places like the Himalayas. With a bit of creativity, you can find them almost anywhere.”

His plan was to complete several iconic routes across Europe, each approached in his own “all-terrain” way. And flying was never an option.

Back from sailing and rock climbing classic routes in the Mediterranean, Tim spent all of February in Cogne (IT), Europe’s ice climbing Mekka. He climbed multiple ice lines including the classic Cold Couloir – a 600-meter icefall – with a client.

Credit: Sandra Boschert

Scaling iconic summits

In April it was then time for the next big challenge. Together with a friend he took on the infamous Eiger North Face in Switzerland.

“Normally there are always tracks, but after heavy snowfall we were the first on the route. It was tough, but also beautiful to move through untouched terrain, feeling like a first ascent.”

In mid-May, Tim and a client skied the 6-day-long Haute Route from Chamonix to Zermatt in just 72 hours, carrying all their food and sleeping outside in their bags. Later in summer, he attempted to travel from Switzerland’s lowest point to its highest in under 24 hours – cycling from Lake Locarno to Zermatt and then running and climbing up Dufourspitze.

“With all the passes, it added up to more than 7,000 positive vertical meters. I missed the deadline by 23 minutes,” he recalls with a smile.

“Connexion Perfetta” expedition

In September, Tim set out on 2025’s grand finale. He began by cycling from the northern tip of Corsica to the start of the GR20, and completed the 180-kilometer trail in five days. Down at the coast, high waves then delayed the swim crossing to Sardinia.

Eventually he and a companion set out, together with a support boat. The rule: that neither could touch it. Halfway across, Tim felt tingling in his hands and feet, then grew seasick.

“All my strength disappeared. But after switching to breaststroke, the nausea finally eased. And once the water calmed, we could continue.”

Reaching Sardinia, he repeated the pattern: cycling, fast mountain running, and more cycling until he reached the island’s southern tip.

“When I look at the map, I think the route forms a beautiful line from north to south. I think adventure is also about creativity and beauty.”

Lead Photo: Christian Jaeggi Photography