Two Nepali Sherpas are taking one-upmanship to an extreme on top of the world.

Pasang Dawa Sherpa and Kami Rita Sherpa, decorated mountain guides and friends, have been scaling Mount Everest in rapid succession in recent days in pursuit of the record for most ascents of the world’s highest peak.

It is a grueling competition with monetary rewards and abundant dangers, turning what is a once-in-a-lifetime experience for most climbers into a repeat performance for the veteran Sherpas.

For decades, the two men have been trying to outdo each other, but the rivalry has heated up this year. Their series of climbs began on May 14, when Pasang Dawa Sherpa, 46, summited Everest for a record-tying 26th time. Days later, Kami Rita Sherpa, 53, regained the crown with his 27th ascent of the mountain.

Then, on Monday, Pasang Dawa Sherpa — eight days after his previous climb — did it again. A day later, Kami Rita Sherpa reached the top once more, for a new mark of 28 summits.