DNF (Did Not Finish)

Starting a race but not completing it. No shame — every runner has a DNF story.

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Understanding DNF (Did Not Finish)

DNF — Did Not Finish — means you started a race but didn't cross the finish line. It appears in your race results instead of a time. Every experienced runner has a DNF story, and while it stings, it's often the right decision when injury, illness, or dangerous conditions make finishing unwise.

Knowing when to DNF is a skill. Legitimate reasons: acute injury (sharp pain that worsens with each step), signs of heat illness (confusion, chills, nausea), medical emergency, or conditions so dangerous that continuing puts you at real risk. Bad reasons for a DNF: "I'm not going to PR" or "this is harder than I expected."

The running community has largely moved past the stigma of DNFs. Elite ultra runners have DNF rates of 30–50% at major races. The conversation has shifted from "never quit" to "know when to quit smart." A DNF that prevents a stress fracture or heat stroke is a victory, not a failure.

Key Facts: DNF (Did Not Finish)

Key facts and insights about dnf (did not finish) that every endurance athlete should know.

DNF = Did Not Finish; DNS = Did Not Star

DNF = Did Not Finish; DNS = Did Not Start

Ultra marathon DNF rates range from 20–5

Ultra marathon DNF rates range from 20–50% depending on the race

Major marathon DNF rates are typically 1

Major marathon DNF rates are typically 1–5%

A DNF does NOT count against future race

A DNF does NOT count against future race entries or qualifications

Pro Tips: DNF (Did Not Finish)

Have pre-set "quit criteria" before the race: what specific conditions would warrant stopping?

DNF if you have acute, sharp pain that's getting worse — finishing injured can mean months of lost training

Don't DNF just because you're having a bad race — sometimes the best growth comes from hard days

If you DNF, walk to the nearest aid station or medical tent rather than trying to find your own way back

Frequently Asked Questions About DNF (Did Not Finish)

No. A DNF means you were brave enough to start, honest enough to recognize a problem, and smart enough to protect your body for future racing. Every professional runner has DNFs. Process the disappointment, learn from it (Was it a training issue? Pacing? Nutrition? Bad luck?), and move forward.

Usually yes — your entry and participation are recorded even without a finish time. For qualifying races (like Boston qualifying attempts), a DNF does not count as a qualification, but your entry is consumed. Check specific race policies for details.