Running 200 Miles Without Sleep: Courtney Dauwalter

What Dauwalter did at Moab 240

The Moab 240 is one of the longest single stage ultra races in North America. The course covers 238 miles of single track and dirt road through Utah desert with multiple climbs and descents. The race attracts elite ultra runners and typically takes the leading finishers 60 to 80 hours to complete.

The athlete

Courtney Dauwalter is an American ultra runner born in 1985 in Minnesota. She transitioned to ultra running from teaching in her late twenties and rapidly became one of the leading ultra athletes in the world across both 100 mile and longer distances. She has won the UTMB, Western States 100, Hardrock 100 and multiple 200 plus mile events.

The 2017 Moab 240

The 2017 Moab 240 was won by Dauwalter in 2 days 9 hours 59 minutes, approximately 58 hours total. She finished over 10 hours ahead of the second place finisher who was male. The race route covered 238 miles through Utah desert with significant elevation. The course is considered one of the most demanding 200 plus mile races in North America.

The sleep total

Across the approximately 58 hour race Dauwalter reportedly slept for approximately 21 minutes in total. This is exceptionally low even for elite ultra runners at this distance. Most competitors at 200 plus mile races take multiple sleep breaks totaling several hours. The minimal sleep approach is one of the distinctive features of her racing style.

Subsequent results

Dauwalter has continued to win major ultra events. She won the Western States 100, Hardrock 100 and UTMB in 2023, becoming the first runner to win all three in the same year. She has set course records at multiple events. Her career has continued to extend the possible upper limits of female ultra endurance performance.

What 240 miles of running demands

Ultra distance running at the 200 plus mile range requires sustained submaximal output across multiple days. The combination of distance, elevation, sleep deprivation and environmental exposure creates a physiological challenge that no other discipline matches.

Energy systems

Ultra distance running occurs primarily through aerobic energy systems. Elite ultra runners have moderate VO2 max values (60 to 70 ml/kg/min for women) but exceptional running economy and fat oxidation capacity. The body shifts toward higher fat oxidation across long events, sparing limited glycogen reserves for harder efforts. Metabolic efficiency matters as much as raw aerobic capacity at this distance.

Caloric demand

A 200 plus mile race expends approximately 25000 to 35000 kcal total depending on body size and conditions. Elite runners consume 200 to 300 kcal per hour during the race. Total intake reaches 10000 to 15000 kcal across 60 plus hours but still falls short of total demand. Significant weight loss across the race is normal.

Muscle damage and recovery

Sustained running for over 50 hours produces extensive muscle damage. Markers including creatine kinase rise dramatically. The legs accumulate damage that takes weeks to fully resolve. Top ultra runners manage the damage through pacing strategy and through training that builds tendon and muscle resistance to repeated impact.

Sleep deprivation tolerance

Most ultra runners at 200 plus mile races take multiple sleep breaks of 1 to 4 hours each. Dauwalter takes minimal sleep and continues to move forward consistently. This requires specific tolerance for sleep deprivation that appears to be partly trainable and partly individual. The cognitive cost of sleep deprivation accumulates and affects pacing decisions. Dauwalter maintains decision quality longer than most competitors.

Why women do well at ultra distances

Female ultra runners increasingly compete with and beat male runners at the longer ultra distances. The pattern has multiple suggested physiological and behavioural explanations. Dauwalter has become the most prominent example of female elite performance at 200 plus mile distances.

Fat oxidation capacity

Women tend to have higher fat oxidation capacity at submaximal exercise intensities than men. This metabolic difference matters more as race duration extends. Glycogen stores deplete and the ability to use fat as fuel becomes the practical limiter. The female metabolic profile may be specifically advantaged at the longest distances.

Pacing patterns

Female elite runners typically pace ultra events more evenly than male runners. This reflects partly physiology and partly different psychological approaches to the events. Even pacing tends to produce better outcomes at very long distances. The advantage compounds as distance increases. Some of the female advantage at 200 plus mile races reflects pacing skill rather than physiology.

Heat and dehydration

Smaller body size relative to typical male runners means lower absolute heat production and better thermoregulation in hot conditions. The Moab desert environment can produce extreme heat. Female runners may have specific advantages in these conditions that contribute to relative competitive performance.

Recovery and persistence

Female ultra runners report different recovery patterns and emotional responses to long efforts. Whether these reflect physiology, training pattern or psychological factors is unclear. The empirical observation is that women often perform relatively better as ultra distances extend. The Dauwalter results are consistent with this broader pattern.

Lessons from Dauwalter

The Dauwalter career illustrates that ultra distance performance limits sit further out than commonly assumed and that elite female athletes can compete with or beat male athletes at the longest distances. The lessons inform thinking about ultra training and gender in endurance.

Sleep deprivation has individual limits

Dauwalter tolerates sleep deprivation during ultra running at levels most competitors cannot match. The tolerance is partly trainable but appears to have a significant individual component. Most ordinary ultra runners benefit from short scheduled sleep breaks. Imitating the Dauwalter approach without similar individual tolerance produces decision failures and DNFs.

Even pacing wins ultras

Dauwalters racing approach involves consistent moderate effort across the entire race. Many competitors start fast and slow significantly in the second half. Even pacing wins more ultras than aggressive starts. The principle is well supported in endurance research. For amateur ultra runners the lesson is to start conservatively and maintain.

Female ultra performance is genuine

The pattern of female ultra runners closing the gap with or beating male competitors at long distances is real and growing. It reflects multiple physiological and behavioural factors. For sports policy and for individual female athletes the implication is that ultra distance is a domain where female performance can match or exceed male performance under appropriate conditions.

The ceiling is not where we thought

A decade ago the 240 mile distance was considered approachable only by a small number of elite male ultra runners. The Dauwalter performance and subsequent results have shifted expectations significantly. Performance ceilings in endurance sport move as more athletes attempt and complete these events. The current best times will likely be exceeded over the next decade.

More from the limits library

For another ultra running story, our 50 Marathons in 50 Days guide covers Dean Karnazes. Mental Override in Ultra Endurance covers the psychological side. And Living Without Sleep for Days covers Randy Gardner and pure sleep deprivation.