Twitter/X

Rachel Entrekin ran 253 miles across Arizona in 56

2026-05-09 · 13:20 UTC ·@dwallacewells ·2 min read

Brief

Rachel Entrekin ran the Cocodona across Arizona (253 miles) in 56:09:48 using five-minute dirt naps, a new world best that shaved 2 hours 37 minutes off Dan Green’s previous mark. She improved from 73:31:25 (2024) to 56:09:48 (2026), outpacing rival Kilian Korth and enduring the 24–90 hour sleep-deprivation window that typically produces hallucinations and psychosis.

Why it matters

Rachel Entrekin ran 253 miles across Arizona in 56:09:48 (five-minute naps only), setting a new all-time best and beating Dan Green’s previous overall record of 58:47:18 by 2 hours 37 minutes on the Cocodona course (38,791 ft ascent, ~34,000 ft descent; daytime highs in the 80s, sub-freezing nights; 125-hour cutoff).

Key details

  • Entrekin cut 17 hours off her own Cocodona time over three attempts: 73:31:25 (2024), 63:50:55 (2025), 56:09:48 (2026). Her closest rival, Kilian Korth (winner of the three biggest 200-mile races in 2025), tried the same five-minute strategy, slept for an hour, and finished 78 minutes behind her.
  • Researchers show extreme sleep deprivation is common and dangerous in ultras: 74% of 100-mile racers reported no sleep; past 200 miles most sleep for hours. A 2023 review found ~1/3 of runners in a 152-mile race who slept under 30 minutes experienced visual hallucinations; hallucinations typically begin 24–48 hours awake and acute psychosis 48–90 hours—Entrekin ran through that window without stopping.
Cleaned source text

Women have been closing the performance gap in ultramarathons for a while. And Rachel Entrekin just delivered a new world’s best performance.

Anish Moonka (@anishmoonka)

Rachel Entrekin just ran across Arizona on five-minute naps. She covered 253 miles, nearly 10 marathons back to back, in 56 hours and 9 minutes. Faster than any human has ever done it.

The race starts in the cactus desert near Phoenix and ends in Flagstaff. Runners climb 38,791 feet over the course (taller than Mount Everest). They descend almost 34,000 feet. Daytime in the desert hits the 80s, while overnight on Mount Elden it drops below freezing. The cutoff is 125 hours, and most finishers need every minute of it.

The course runs across trail, rocky dirt roads, and pavement. She held a 13-minute-mile pace, the speed of a steady jog, for two and a half straight days.

Going that long without sleep is medically dangerous. A 2023 review of ultramarathon research found that in one 152-mile mountain race, about a third of runners who slept under 30 minutes had visual hallucinations. Seeing things that aren't there usually starts after about 24 to 48 hours awake. Severe loss of touch with reality, often called acute psychosis, sets in between 48 and 90 hours. Entrekin ran straight through that entire window without stopping.

Her three Cocodona times: 73:31:25 in 2024, 63:50:55 in 2025, 56:09:48 this year. She has cut 17 hours off her own time in three attempts. The previous overall record, set by Dan Green, was 58:47:18, and Entrekin beat it by 2 hours and 37 minutes. At the finish, she said: "I feel fine, that was insane."

— https://nitter.net/anishmoonka/status/2053007059554054428#m