Endurometry
Derive easy, marathon, threshold and interval paces from a recent race, not a plan you copied. About 80% of volume should stay genuinely easy. If you cannot talk, it is not an easy run.
Last updated October 5, 2026
Training paces are a way of making sure each session does the job you intended. Run your easy days too fast and you cannot run your hard days hard enough — that is the whole failure mode, and it is extremely common.
Get your paces from a race, not from a plan you found online
Paces are personal. Enter a recent race result into the training pace calculator and it derives your easy, marathon, threshold and interval ranges from that performance. Twenty seconds per kilometre matters here: a pace that is genuinely easy for one runner is a threshold session for another.
What each pace is for
| Pace | Roughly | Purpose |
|---|---|---|
| Easy / recovery | 60–75% of your race pace effort | Volume. Builds the aerobic base that everything else sits on. |
| Marathon pace | The pace you could race 42.195 km at | Specific endurance plus fuelling and kit rehearsal. |
| Threshold | Pace you could hold for about an hour | Raises the ceiling you can sustain before lactate accumulates. |
| Interval (VO2max) | 3K–5K pace | Short repeats, 2–5 min, with full recovery. |
| Repetition | Mile to 3K pace | Speed, economy and running form. |
The 80/20 rule, in practice
Around 80% of your weekly volume should be genuinely easy and about 20% should be hard enough to matter. When runners say they train 80/20 and see no progress, the usual cause is that their "easy" is really a moderate effort — so the hard sessions lose their edge and the week becomes uniformly tiring. If you can measure it, keep easy runs clearly below the point where breathing needs to be managed by the heart rate zones; if you would rather not, use the talk test.
Check the arithmetic before you trust the plan
Convert your paces between min/km, min/mile and km/h with the pace converter so the plan you are following (often written in whichever unit you do not use) actually means what you think. And sanity-check target times with the race time predictor before a training block gets built on an unrealistic number.
Related Tools
Training Pace Calculator (VDOT Zones)
Get your VDOT from a recent race and see easy, marathon, threshold, interval and repetition pace zones plus heart-rate zones.
Running Pace Calculator
Enter distance and finish time to get your pace per km and mile, average speed and per-kilometre splits.
Running Pace Converter
Convert between min/km, min/mi, km/h and mph, and see the implied finish time for 5K, 10K, half marathon and marathon.
Related guides
VDOT explained
VDOT is Daniels’ endurance index from a race, not a lab VO2max. How Endurometry gets 41.5 from a 10K in 48:30 and turns it into Easy, Threshold and Interval paces.
Easy, Tempo and Long Run Paces
One comparison table for the three intensities every plan is built from: easy, tempo and the long run — with heart-rate %, VDOT % and the pace range that goes with each.
General Physical Preparation for Runners (GPP)
What general physical preparation (GPP, or PPG in French) is, why runners need it, 10 key exercises, a 30-minute session and an 8-week plan that fits around your running.
How the numbers are calculated
Frequently Asked Questions
How do I know my easy pace is easy enough?
You should be able to hold a full conversation. If you cannot, it is not an easy run regardless of what the watch says.
How often should I run threshold?
Once a week for most runners, occasionally twice. Threshold sessions take more out of you than they feel like they do.
Should I train by pace or by heart rate?
Pace for structured sessions on flat ground, heart rate for hot days, hills and recovery runs. The two disagree exactly when conditions change.
Want a new tool or fix?
Tell us which calculator, pace chart or fix would help — we build what runners ask for. Replies usually come back in 1–2 days.