VDOT is a performance-based aerobic fitness index developed by Jack Daniels. It reflects your effective VO2max from race performance — a higher VDOT means faster potential across all distances.

Which formula is used?

The calculator uses the Daniels & Gilbert (1979) VDOT methodology from 'Daniels' Running Formula'. It derives training paces from the oxygen cost of running at your race velocity.

What training zone should I use for most of my runs?

Zone E (Easy) — typically 60–80% of training volume should be easy pace. Most runners train too fast for their easy days, which limits recovery and aerobic adaptation.

How current does my race time need to be?

Ideally within the last 8–12 weeks and from a well-paced effort. A hard time trial works too. Results from a poorly-paced race or extreme conditions may not reflect your true fitness.

Is this tool free and private to use?

Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.

Do these paces replace a coach's plan?

No. These are evidence-based starting points. A qualified running coach can adjust for your training history, injury risk, and race goals.

Methodology: Run Training Paces Calculator

Scope

Returns Daniels-VDOT training paces (Easy, Marathon, Threshold, Interval, Repetition) from a recent race result.

Formula

VDOT = f(race_distance, race_time). Each pace = pace_factor(VDOT, zone).

Coefficients

Parameter	Value	Note
Easy pace range	`~0.59–0.74 of VDOT`
Marathon pace	`~0.84 of VDOT`
Threshold pace	`~0.88 of VDOT`
Interval pace	`~0.98 of VDOT`
Repetition pace	`~1.05 of VDOT`

Data sources

Daniels J. Daniels' Running Formula. 4th ed. Human Kinetics, 2021. — Publisher page for the current edition; source of the VDOT tables and pace coefficients.
Daniels J, Gilbert J. Oxygen Power: Performance Tables for Distance Runners. Tempe, AZ, 1979. — Original VDOT tables; self-published monograph with no stable online source.
Daniels JT, Yarbrough RA, Foster C. Changes in VO2 max and running performance with training. Eur J Appl Physiol Occup Physiol. 1978;39(4):249-254. — PMID 710390. Underlying physiology that Daniels later compiled into the VDOT framework.

Assumptions

Reference race was all-out and recent (<6 weeks old).

Approximation range

VDOT under-estimates fitness for athletes coming off a training block and over-estimates during heavy load.

Limitations

Daniels' system is calibrated on middle-to-long-distance track and road runners; ultra-endurance athletes should use different pace prescriptions.
Pace is not the same as effort — heat, wind, and terrain override the table.

Reproducibility

5K in 22:00 → VDOT ~45. Easy pace ~5:15–5:40/km. Threshold pace ~4:25/km.

Change log

2026-04-24: methodology page first published.

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Walking Calorie Calculator — Estimate calories burned from walking using speed, duration, body weight, and incline.
Calories Burned Calculator — Estimate exercise calorie burn from body weight, duration, MET intensity, and incline.

Worked example

Computed by the same engine bundle served at /engines/run-training-paces-calculator.js. Re-runnable: the values below are the literal output of compute(engineInput).

Input

tool: run_training_paces_calculator
distance: 5k
race_time_minutes: 25
race_time_seconds: 0

Output

vdot: 38.3
inputRaceDistanceMeters: 5000
inputRaceTimeSeconds: 1500
inputPacePerKmSeconds: 300
zones: [{"zone":"E","label":"Easy / Long Run","description":"Conversational pace for aerobic base and recovery. Use for most training volume.","pacePerKmSeconds":393,"pacePerMileSeconds":632,"effortPercent":67},{"zone":"M","label":"Marathon Pace","description":"Comfortably hard. Race-specific feel for marathon training runs.","pacePerKmSeconds":345,"pacePerMileSeconds":555,"effortPercent":79},{"zone":"T","label":"Threshold / Tempo","description":"Comfortably hard sustained effort. Improves lactate threshold. Max 20 min continuous.","pacePerKmSeconds":322,"pacePerMileSeconds":519,"effortPercent":86},{"zone":"I","label":"Interval / VO₂max","description":"Hard 3–5 min repeats near VO₂max. Builds aerobic power. Typical rep: 800m–1200m.","pacePerKmSeconds":291,"pacePerMileSeconds":469,"effortPercent":98},{"zone":"R","label":"Repetition / Speed","description":"Short fast reps (200m–400m) with full recovery. Develops economy and speed.","pacePerKmSeconds":264,"pacePerMileSeconds":425,"effortPercent":110}]
equivalentRaceTimes: [{"distance":"1,500m","distanceMeters":1500,"predictedSeconds":411},{"distance":"1 Mile","distanceMeters":1609.34,"predictedSeconds":444},{"distance":"5K","distanceMeters":5000,"predictedSeconds":1500},{"distance":"10K","distanceMeters":10000,"predictedSeconds":3113},{"distance":"Half Marathon","distanceMeters":21097.5,"predictedSeconds":6903},{"distance":"Marathon","distanceMeters":42195,"predictedSeconds":14275}]

FAQ

What is VDOT?: VDOT is a performance-based aerobic fitness index developed by Jack Daniels. It reflects your effective VO2max from race performance — a higher VDOT means faster potential across all distances.
Which formula is used?: The calculator uses the Daniels & Gilbert (1979) VDOT methodology from 'Daniels' Running Formula'. It derives training paces from the oxygen cost of running at your race velocity.
What training zone should I use for most of my runs?: Zone E (Easy) — typically 60–80% of training volume should be easy pace. Most runners train too fast for their easy days, which limits recovery and aerobic adaptation.
How current does my race time need to be?: Ideally within the last 8–12 weeks and from a well-paced effort. A hard time trial works too. Results from a poorly-paced race or extreme conditions may not reflect your true fitness.
Is this tool free and private to use?: Yes. AI Fit Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.
Do these paces replace a coach's plan?: No. These are evidence-based starting points. A qualified running coach can adjust for your training history, injury risk, and race goals.