As darkness covered the slopes of Mount Everest, an American ultra-runner quietly began one of the most dangerous endurance attempts in modern Himalayan history. Tyler Andrews, 35, left Everest Base Camp aiming to summit the world’s highest mountain and return back down in one continuous push without using supplemental oxygen.
If successful, Andrews could break one of Everest’s longest-standing speed records: the no-oxygen ascent benchmark of 20 hours and 24 minutes set by Kaji Sherpa in 1998. A record that has survived for 27 years despite countless elite climbers attempting to challenge it.
Tyler Andrews
Tonight, somewhere high above the Khumbu Icefall, Andrews is still climbing through freezing temperatures, thin air, and complete darkness.For the global mountaineering community, this is more than just another Everest expedition. It is a test of human endurance at the highest level possible.
Who Is Tyler Andrews?
Tyler Andrews is an American endurance athlete and ultra-runner known for pushing extreme limits in high-altitude environments. Over the past several years, he has built a reputation for combining elite ultramarathon fitness with ambitious mountaineering objectives across the Himalayas.
Unlike traditional expedition climbers who spend weeks slowly moving between camps, Andrews approaches Everest with a speed-focused alpine strategy. His goal is efficiency, continuous movement, and minimal downtime.
That approach requires extraordinary conditioning. Climbers attempting speed ascents on Everest must move rapidly while carrying limited gear, managing dangerous terrain, and surviving severe oxygen deprivation. Andrews is not new to Everest either.
In 2025, he attempted a similar no-oxygen speed ascent from the south side of the mountain but turned back near 7,400 meters after conditions worsened. Rather than forcing the climb, he chose to retreat safely a decision many experienced mountaineers respected given Everest’s unpredictability.
Instead of walking away from the challenge entirely, he returned stronger.
The Record Tyler Andrews Is Trying to Break
The target is one of Everest’s most respected endurance records. In 1998, Nepali climber Kaji Sherpa completed a remarkable no-oxygen speed ascent of Mount Everest in 20 hours and 24 minutes. Even decades later, the achievement remains legendary in mountaineering circles because of how physically demanding it is.
Climbing Everest without supplemental oxygen is already considered one of mountaineering’s greatest tests. Attempting to do it at record pace increases the difficulty dramatically.
Above 8,000 meters often called the “death zone” oxygen levels are so low that the human body begins deteriorating rapidly. Recovery becomes nearly impossible. Decision-making weakens. Muscles lose efficiency. Even basic movement becomes exhausting.
Most climbers rely on bottled oxygen to improve safety and increase their chances of reaching the summit. Andrews is attempting to do the opposite while moving faster than almost anyone in Everest history.
Climbing Everest Without Oxygen
Mount Everest stands at 8,848.86 meters (29,031 feet), where atmospheric oxygen levels are only about one-third of what humans experience at sea level.
Without supplemental oxygen, climbers face extreme physiological stress including:
- Severe fatigue
- High-altitude cerebral edema (HACE)
- High-altitude pulmonary edema (HAPE)
- Reduced mental clarity
- Dangerous body temperature loss
- Increased risk of collapse
Even experienced climbers can become disoriented or unconscious at extreme altitude.
The challenge becomes even more intense during speed attempts because athletes push their cardiovascular systems continuously for long periods without proper recovery. This is why very few mountaineers attempt Everest speed records without oxygen.
His 2025 Everest Training Was Already Extreme
Before returning to Everest this season, Andrews completed one of the most unusual endurance training efforts ever associated with the mountain.
In December 2025, he reportedly set a world record for the fastest treadmill ascent equivalent of Everest’s total elevation gain. Andrews completed the full 8,848-meter vertical climb simulation in just 8 hours, 17 minutes, and 9 seconds.
Although treadmill climbing and real Himalayan terrain are entirely different challenges, the training effort demonstrated the enormous physical preparation behind this Everest attempt.
The real mountain, however, is unforgiving.
No treadmill can simulate:
- Avalanche risk
- Icefall exposure
- Extreme cold
- Altitude sickness
- Weather shifts
- Mental pressure inside the death zone
Tonight’s climb is the true test.
Everest Speed Climbs and the Debate Around Them
Speed ascents on Everest have become increasingly discussed in the mountaineering world over the past decade.
Some climbers view them as the highest expression of alpine fitness and mountain efficiency. Others argue that Everest is already overcrowded and dangerous, making rapid summit pushes even riskier.
Supporters of fast ascents believe experienced athletes moving quickly can reduce exposure time in dangerous areas like the Khumbu Icefall and death zone.
Critics argue that Everest’s unpredictability means even elite athletes can face sudden weather changes, route congestion, or altitude emergencies beyond their control.
Regardless of opinion, no-oxygen speed ascents remain among the most respected accomplishments in high-altitude mountaineering because they require immense physical conditioning and mental resilience.
Nepal Remains the Center of Global Mountaineering
Every major Everest story ultimately returns attention to Nepal and the Himalayas.
From legendary Sherpa climbers to modern expedition logistics, Nepal remains the heart of the global mountaineering world. Each climbing season attracts athletes, adventurers, filmmakers, scientists, and endurance specialists from across the globe.
The 2026 Everest season has already drawn international attention with:
- High summit numbers
- Multiple climbing records
- Increased speed attempts
- Young climbers reaching the summit
- Renewed discussions around Everest safety
Now Tyler Andrews’ attempt adds another dramatic chapter to this year’s Himalayan climbing season.
Somewhere Above Everest, Tyler Andrews Is Still Climbing
As this story develops, Tyler Andrews continues his push toward the summit of Mount Everest without supplemental oxygen. In freezing darkness high above Nepal’s Khumbu region, every step becomes harder. Every breath becomes thinner.
The record he is chasing has stood untouched for nearly three decades. Whether he succeeds or not, the attempt itself represents one of the boldest endurance challenges on Earth. And somewhere tonight, far above the clouds of the Himalayas, Tyler Andrews is still climbing.
Frequently Asked Questions
Who is Tyler Andrews?
Tyler Andrews is an American ultra-runner and endurance athlete known for high-altitude mountain challenges and extreme endurance projects.
What record is Tyler Andrews trying to break?
He is attempting to break the Mount Everest no-oxygen speed record of 20 hours and 24 minutes set by Kaji Sherpa in 1998.
Is Tyler Andrews using supplemental oxygen?
No. Andrews is attempting the climb without bottled oxygen support.
What is the Everest death zone?
The death zone refers to altitudes above 8,000 meters where oxygen levels become dangerously low for human survival.
Why is climbing Everest without oxygen dangerous?
Without supplemental oxygen, climbers face severe altitude stress, fatigue, impaired thinking, and life-threatening medical risks.
Where is Mount Everest located?
Mount Everest is located in the Himalayas on the border between Nepal and Tibet/China.