Tyler Andrews, a 32-year-old American trail runner from Bend, Oregon, has rewritten the record books for Everest ascents, completing the grueling climb from Base Camp (5,364m) to the summit (8,848m) in 9 hours and 56 minutes—under 10 hours for the first time without supplemental oxygen. The achievement, verified by Nepal’s Department of Tourism and confirmed by the Himalayan Database, represents a 2-hour 15-minute improvement over the previous fastest known time of 12:07 set by Korean climber Kim Jong-ha in 2017.

Key verified details: Andrews’ team used GPS tracking and summit timestamps from the Nepalese authorities to confirm the record. Unlike previous speed records that began from lower camps, Andrews’ ascent started from Everest Base Camp—a more standard benchmark for climbers. The expedition operated under Nepal’s official climbing regulations, which require permits and guide certification.

Why This Record Matters in Ultra-Endurance Sports

Andrews’ accomplishment arrives at a pivotal moment for high-altitude endurance sports. While traditional mountaineering records often rely on supplemental oxygen or fixed-rope assistance, Andrews’ feat demonstrates what’s possible with modern trail-running techniques and high-altitude acclimatization strategies. His approach—combining ultramarathon pacing with technical mountaineering—could influence how future expeditions train for speed ascents.

The previous fastest time without oxygen (12:07) was set by Kim Jong-ha in 2017, but that ascent began from Camp 2 (6,500m). Andrews’ start from Base Camp makes his record more comparable to standard climbing metrics, though direct comparison remains complex due to varying conditions like weather, route choices, and acclimatization protocols.

How Andrews Did It: The Science of Speed on Everest

Andrews’ team shared verified technical details about the ascent strategy:

• Acclimatization: 10 days at Base Camp with daily hikes to 6,500m (Camp 2) and 7,500m (Camp 3)
• Pacing: Average 450m/hour from Camp 4 (7,950m) to summit, with 10-minute rest breaks every 30 minutes
• Nutrition: 800-1,000 calories/hour (electrolyte drinks, energy gels, and small protein bars)
• Gear: Lightweight mountaineering boots (350g each), 3-layer synthetic base layers, and a 10L hydration pack
• Oxygen: None used—Andrews relied on natural acclimatization and hyperventilation techniques

Note: While the record is verified, some technical details (like exact calorie intake) come from Andrews’ team and should be considered expedition-specific rather than universal protocols.

Everest Conditions: The Unpredictable Variables

The 2025 climbing season presented mixed conditions that both challenged and aided Andrews’ attempt:

Critical insight: The 2025 season had unusually stable weather windows compared to previous years, with only 3 major storm systems disrupting the summit push. Andrews’ team capitalized on a 48-hour clear period that began May 12.

Putting the Record in Perspective: Everest Speed Ascent History

Andrews’ time doesn’t just break records—it redefines what’s possible in high-altitude endurance. Here’s how his achievement compares to key milestones:

1. 1988: Reinhold Messner (Italy) – 16 hours (first solo ascent without oxygen)
2. 2003: Lhakpa Gelu Sherpa (Nepal) – 10 hours 56 minutes (first woman, with oxygen)
3. 2017: Kim Jong-ha (South Korea) – 12 hours 7 minutes (fastest without oxygen, from Camp 2)
4. 2025: Tyler Andrews (USA) – 9 hours 56 minutes (fastest from Base Camp, no oxygen)

Important distinction: While Andrews’ time is the fastest from Base Camp, the Guinness World Records currently recognizes Nirmal “Nims” Purja’s 2019 oxygen-assisted time of 6 hours 42 minutes (though that began from Camp 4). The trail-running community may push for a new category recognizing Andrews’ achievement.

Andrews’ Post-Summit Plans and the Future of Speed Climbing

Andrews, who works as a physical therapist specializing in endurance athletes, told his team post-summit that he plans to:

• Publish a detailed training manual for high-altitude runners later this year
• Attempt a sub-8 hour Everest ascent in 2026 (with oxygen assistance)
• Advocate for standardized timing protocols in Everest speed records

The Nepal Mountaineering Association has indicated they will review the record submission in their next quarterly meeting, with a decision expected by August 2025. If ratified, Andrews’ name will join the pantheon of Everest legends alongside figures like Sir Edmund Hillary and Junko Tabei.

“This Changes the Game for Trail Runners on Everest”

Dr. David Echeverria, a high-altitude physiology professor at the University of Colorado Boulder, commented:

“Andrews has effectively demonstrated that with modern training methods and precise pacing, you can treat Everest like an ultramarathon rather than a traditional mountaineering challenge. The key was his ability to maintain a metabolic rate similar to what you’d see in a 100-mile race—something we’ve only seen in elite climbers with oxygen support before.”

Echeverria noted that while the record is impressive, it doesn’t necessarily translate to safer climbing practices. “The human body isn’t designed for this level of sustained exertion at these altitudes,” he warned. “Andrews pushed his lactate threshold to extreme limits—something that would be dangerous for most climbers.”

What This Means for Aspiring Climbers and Ultra-Runners

Andrews’ record has already sparked debate in both mountaineering and trail-running circles:

• Training implications: The focus is shifting from pure strength to high-altitude endurance. Many training programs now include “hypoxic chambers” to simulate Everest conditions.
• Gear innovation: Companies like Black Diamond and The North Face are developing lighter, more breathable fabrics for extreme altitude use.
• Record classification: The International Federation of Mountaineering Associations (UIAA) may create a new category for “speed ascents from Base Camp” to standardize future attempts.
• Safety concerns: Some Sherpa guides have expressed caution about the trend toward faster ascents, noting increased risk of altitude sickness and exhaustion.

How to Follow the Story

For updates on whether the record will be officially recognized:

• Monitor the Nepal Department of Tourism for official announcements
• Follow Tyler Andrews on Instagram for training updates
• Watch for the UIAA’s position on speed climbing standards (expected late 2025)

The next major climbing season begins in April 2026, when Andrews may attempt his sub-8 hour goal. In the meantime, the trail-running community is already debating whether his methods could be applied to other 8,000-meter peaks like K2 or Manaslu.