Karl Egloff Speeds Up Aconcagua to Prep For Everest in a Day

Karl Egloff of Ecuador has broken an unusual speed record on Aconcagua. He ran from Base Camp to the main and south summits and back in 8 hrs 49 min. That is just an appetizer for his main 2025 challenge: This spring, he plans to run up Everest in a day without oxygen.

Egloff trained on Aconcagua for seven days before setting off from Base Camp in the Plaza de Mulas on Thursday at 7.30 am. He ran all the way to the main summit (6,961m), then crossed the summit ridge to the south summit (31m lower) and returned to Base Camp.

Egloff on the main summit of Aconcagua. Photo: Egloff’s website

“The ridge to the south summit was demanding,” he wrote on social media. “[But] it was always my dream to complete both summits in a single push from Base Camp.

As far as Egloff is aware, this route (that includes the south summit) has not been completed in a single day before.

A watch showing the time done on a speed Aconcagua climb.

The speed record on Egloff’s watch. Photo: Karl Egloff

Aconcagua feels like a second home for the climber and trail runner, who moved from his Ecuadorian homeland to Switzerland two years ago. On the roof of South America, he has already broken two speed records: the route from Horcones-summit-Horcones in 11 hrs 52 min (2015), and the difficult South Wall in 25 hours in 2020.

Seven Summits in a day: Everest next

This is not the biggest project Egloff has in mind this year. In fact, Aconcagua is only one stage of the Seven Summits, which Egloff plans to run, breaking a speed record on each one. Besides Aconcagua, he has ticked off Kilimanjaro, Elbrus, and Denali over the last decade. Everest is next.

Screenshot of a website with Karl Egloff's records printed.

Egloff’s records on the Seven Summits. Photo: Karlegloff.com

Egloff intends to climb Everest from Base Camp to the summit and back in less than 24 hours without oxygen from the South Side. His regular climbing partner, Nico Miranda, will accompany him. Miranda will carry an oxygen system as a safety backup. This way, they hope to avoid trouble with the new set of Nepalese regulations around Everest, which restrict solo, independent climbers.

A second Everest speed runner

From Aconcagua Base Camp today, Egloff told ExplorersWeb that he and Miranda will not be the only ones attempting the Everest speed record. Tyler Andrews of the U.S. will also be there.

“Andrews and I will not climb at the same time, but on different days, but both will keep the same style: a single no-oxygen push, from Base Camp to summit to Base Camp,” he explained.

Andrews has made several FKTs in Nepal in the last three years, including the fastest times on Manaslu and Ama Dablam.

We will ask Egloff for further details after he returns to Switzerland in a few days. As we post this story, he is again running from Base Camp to the summit of Aconcagua in another brutal training session.

“That’s why I came here, to train hard and get my body (and mind) super strong at altitude,” he told us.

High-altitude racer

Egloff is no newbie to skyrunning at high altitudes. Fast climbing on high mountains, both in Ecuador and abroad, has long attracted him.

Yet it was only after soloing Ecuador’s Cotopaxi in 1hr 26min from the hut to the summit and back in 2022 that he decided to focus on speed climbing. In May of that year, he set the FKT on Makalu with Nico Miranda. The pair climbed from Advanced Base Camp to the summit in 17 hrs 18 min and completed the round trip in 25 hours.