Run Long After 60

A free framework for runners

DNF: Data,
Not Failure

For anyone who has ever not crossed a finish line.

"Did Not Finish" is a race-system label. It is binary, externally imposed, and indifferent to your intent.

It does not tell you why. It does not tell you whether you failed. It does not tell you whether you belong in this sport.

What you do with the data determines what comes next.

Open the After Action Review → What is this?

The framework

Five lenses. One clear constraint.

Most runners either explain a DNF away or internalize it as a personal verdict. Neither response is useful. This framework replaces both reactions with honest analysis — usable after a DNF, a cutoff pull, a medical stop, or a finish that felt wrong.

LENS 1
System constraints
Cutoffs · permits · course design
LENS 2
Physical capacity
Strength · speed · durability
LENS 3
Execution
Pacing · fuel · hydration · gear
LENS 4
Decision points
Voluntary · cutoff · medical
LENS 5
Outcome + constraint
One sentence. One adjustment.

DNFs should never be used to exile someone from running. Getting a DNF — or two, or three, or many — does not mean you shouldn't be here.

— Mark Vega, DNF: Data, Not Failure
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Post-Race After Action Review

Complete within 48 hours while the data is fresh. Works after a finish, a DNF, or a DNS — at any distance, any age.

Start
Done

Start here

Race information

No stories until constraints are named. Complete this first.

Rule 1: No stories until constraints are named. If you cannot clearly state what limited you, you are not ready to interpret the race.
Rule 2: Fewer conclusions beat better excuses. One accurate constraint is more valuable than five emotional explanations.

Lens 1 of 5

System constraints

The race you entered. This is where analysis must begin. Always. Cutoffs are not moral — they are operational.

Common mistake: Treating cutoffs as personal judgments rather than operational math.

Lens 2 of 5

Physical capacity

Not "how fit did you feel?" — but "what could your body deliver, repeatedly, under load, on that terrain, that day?"

Common mistake: Confusing endurance fitness with speed capacity. They are not the same thing. A runner can be fit and still be too slow for the course.

Lens 3 of 5

Execution

Where responsibility lives — and where learning is most actionable. Isolate variables: what was within your control?

Common mistake: Treating any problem that occurred during the race as the cause of the DNF. Correlation is not causation.

Lens 4 of 5

Decision points

Where the race changed. Separating forced outcomes from chosen outcomes — without moral judgment.

Common mistake: Treating voluntary DNFs as weakness, or forced DNFs as injustice. Both are data.

Lens 5 of 5

Outcome and constraint

Now — and only now — do you earn the right to summarize the race. Use mechanical language, not emotional language.

Primary constraint

State it in one sentence. If you can't, the analysis is incomplete. Replace judgment with mechanics: not "I failed" but "my movement rate was incompatible with the cutoffs on that course that day."

Post-race after action review

DNF: Data, Not Failure

Created by Mark Vega · Run Long After 60 · datanotfailure.org

After action review

Race summary

Outcome

Conditions

Cutoff interaction

Lens 1 — System constraints

Lens 2 — Physical capacity

Lens 3 — Execution

Lens 4 — Decision points

Primary constraint

Secondary contributor

One forward adjustment

What to keep

If the same constraint appears across multiple races, it is no longer incidental. It is structural.

DNF: DATA, NOT FAILURE · CREATED BY MARK VEGA · RUN LONG AFTER 60 · DATANOTFAILURE.ORG · FINISH IS OPTIONAL. LEARNING IS NOT.

About this framework

DNF: Data, Not Failure was created by Mark Vega — practicing lawyer, stroke survivor, and endurance runner. It exists because DNFs are poorly understood, inconsistently reported, and wrapped in shame that prevents honest analysis.

A DNF can happen to anyone at any distance, at any age, at any point in their running life. A 15-year-old trying a 10K for the first time and a 65-year-old attempting a 100-miler both deserve the same thing after not finishing: not shame, but a framework for understanding what actually happened.

The full guide — including Cutoffs 101, the Age and Strength section, and the complete framework — is available at runlongafter60.com.

© 2026 MARK VEGA RUN LONG AFTER 60 FINISH IS OPTIONAL. LEARNING IS NOT.