Start with a race you can describe honestly
Use a recent result and enter the distance and time accurately. Add context before treating the output as a training target: was the course measured, was the effort representative, and did conditions or terrain materially change the result? A precise score cannot repair an uncertain input.
Read the equivalent times as a model
A 20:00 5K produces a CORE Fitness Score of about 49.8 in this implementation, with model equivalents near 41:28 for 10K and 3:11:17 for a marathon. The marathon number assumes more than speed over 5K. Your endurance preparation, fueling and the course decide whether it is a sensible race goal.
Worked example: a 20-minute 5K
Enter 5K and 20:00 in the calculator. The table below is computed from our implementation, rounded to the nearest second. It is an example of reading the result, not a workout prescription or an exact reproduction of the official VDOT pace tables.
| Range | Minutes per km | Minutes per mile | Decision to make |
|---|---|---|---|
| Easy | 4:54–5:53 | 7:54–9:28 | Conversation should stay comfortable; adjust to the day. |
| Marathon | 4:29–4:35 | 7:13–7:22 | A modeled reference; check long-run preparation before using it. |
| Threshold | 4:16–4:21 | 6:52–7:00 | Controlled sustained work; duration and recovery still matter. |
| Interval | 3:51–3:57 | 6:11–6:21 | Hard aerobic work; the table does not prescribe repetitions. |
| Repetition | 3:34–3:42 | 5:44–5:57 | Short speed with relaxed form and sufficient recovery. |
Which pace should you use tomorrow?
Choose the session first, then read the relevant pace range. Easy running, sustained work and short repetitions serve different purposes. A score does not tell you how many hard sessions belong in your week or how much recovery you need. That is the plan-design decision around the numbers.
Update when the evidence changes
Save the source result and its date with the pace chart. Use a newer representative performance when you have one, rather than adjusting the score upward after every good training day. CORE Fitness Score credits the Daniels–Gilbert equations; it is not a measured laboratory VO2max or an affiliation with V.O2.
When two races give you different scores
Imagine a recent 5K gives a higher score than your recent half marathon. Keep both results and investigate the mismatch: were the courses comparable, did you pace both well, and were conditions similar? If the longer race was representative, its slower equivalent is useful evidence when choosing a marathon goal. Selecting only the highest score hides the very limitation the comparison can reveal.
Three ways to misuse an accurate calculation
- Entering a goal time as though you already raced it: you get the training references for that hypothetical performance, not evidence of your present ability.
- Running the fastest end of Easy every day: the range is a reference, while the purpose is comfortable running. If heat, hills or fatigue change the effort, a pace target needs context.
- Adding workouts because the table lists five categories: the output describes intensities, not five sessions to fit into every week.
A useful note to keep with your chart
Record the race date, measured distance, finish time, course and conditions. Add the purpose of your next session and the pace range you intend to use. Afterward, write what you actually did and how it felt. This turns a one-time score into a record you can discuss, rather than a number that silently changes the whole plan.
Bring the result and the context
Enter a recent race, then save the distance, time, conditions and date with your pace chart. Select the range for the session you are actually doing. If the result came from an unusually hot race or a difficult course, discuss that context before substituting a faster hypothetical result.
Common questions
Which race should I use?
Choose a recent representative result and the actual measured distance. A downhill, hot or interrupted race needs context rather than a hidden correction.
How do the training bands differ?
The tool shows Easy, Marathon, Threshold, Interval and Repetition ranges. They organize intensity; the repetition duration and recovery still determine the workout.
Why is the marathon equivalent not my race plan?
Equivalent aerobic performance does not establish marathon durability or fueling tolerance. Check preparation before adopting the modeled time.
What does a score change mean?
Compare dated races, including distance and conditions. A trend made from very different events is evidence to review, not automatic proof of a precise fitness change.
Should I train at my goal VDOT or my current race score?
Use a recent representative race to describe current ability. Entering a goal time is a hypothetical comparison; it does not show that you can sustain those training intensities today.
PUT IT INTO PRACTICE
Take the next step.
Sources & author
References and further reading. Research findings, practical examples and coaching interpretation are different kinds of evidence.
