DNFs: The Ultramarathon Emotional Toll
Ultramarathon runners often face the emotional fallout of a DNF (Did Not Finish), a common outcome with race attrition rates sometimes reaching 40%.
A DNF, or "Did Not Finish," is the acronym no ultrarunner wants beside their race result. For amateur runners, it is loaded with unspoken emotions like failure, disappointment, and shame. DNF rates vary wildly but are extremely common in ultramarathons. Attrition can range from 15% to 40% depending on conditions, as seen in the stats for major events. Specific races illustrate this volatility.
| Race (Year) | DNF Rate |
|---|---|
| Ultra Trail du Mont Blanc (2026) | 30% |
| Ultra Trail du Mont Blanc (2025) | 35.8% |
The 2026 Ultra Trail du Mont Blanc was held from 28-30 August. The higher 2025 rate was attributed to driving rain, strong winds, and biting cold.
The Immense Investment Before the Start
An ultramarathon represents the culmination of months or years of training. Runners often spend 10 to 20 hours a week running, fitting sessions around work and family. This investment of time and money compounds mentally, making a DNF particularly hard to accept.
Robbie Williams, a civil engineer from Melbourne, experienced this after his 2023 DNF at the Tarawera Ultra-Trail Miler, a 160km race in New Zealand. He had trained for hundreds of hours over three years, with the race previously cancelled twice due to Covid-19.
Physical Breakdowns and 'What Ifs'
Physical issues are a primary cause for dropping out. About 18 hours into his 160km race, Williams felt increasingly unwell. Light-headed, nauseous, and beginning to stumble, he reached the 105km checkpoint slightly delirious around midnight.
He realized he had substantially overdosed on salt tablets, leading to extreme dehydration and hypernatraemia. Confused, irritable, and fatigued, he pulled out. He later believed he could have finished if he had rested.
He said he was massively disappointed in himself and full of 'what ifs' for a long time.
The Psychological Weight of a DNF
Emotional factors can be just as decisive as physical ones. The author of the source excerpt describes their own experience at kilometre 62 of a 100k ultramarathon, drenched, freezing, and with a GI catastrophe, deciding to quit after a rational calculation about risk. Sarah Houston, a 42-year-old gym owner and personal trainer, signed up for a 100km ultra during a relationship separation.
As race day neared, her original motivation diminished. She said with so much happening in her life, the original goals had diminished so much she was left wondering why she was doing it. She lacked the emotional bandwidth for the intense training.
She started the race but DNFd at 78km. She explained she just started to think she really didn't want to run any more.
The Elite Perspective on Strategic Withdrawals
Elite athletes also DNF, but it is often viewed as a strategic decision. Damian Hall, a record-breaking ultrarunner, DNFd the 268-mile Spine race in 2022 while leading by roughly four hours. After more than 52 hours, he withdrew around the 180-mile mark due to a sharp groin pain he feared would cause long-term injury.
He admits he was annoyed with himself for a few weeks. He suggests elites may DNF more often because ambitious goals push them closer to their limits. Hall reframes the experience, saying a DNF doesn't mean you've failed, it's just part of the journey.
The source concludes with runners moving forward. The author completed another 100km race. Williams finished Tarawera in 2026. Houston plans another attempt. As the author's coach, Joe, stated: "Athletes lose games, lawyers lose cases, entrepreneurs lose money. Winners lose." For more on race schedules and results, see our fixtures and standings pages.