What this result means
Training paces here come from Jack Daniels’ VDOT system. A recent race distance and time estimate VDOT, an index of current endurance fitness. That value is converted into recovery, easy, tempo, threshold, and interval paces.
The bands are slower than all-out race pace on purpose. Easy running is meant to be easy. If your last race was a blow-up or a downhill special, VDOT will misread fitness. Pick a representative result.
A 20-minute 5K is roughly VDOT 50. Easy running sits slower than 5K race pace; threshold is faster than easy and slower than interval work. A 40-minute 10K produces a different VDOT and a different set of bands — not a simple “add a few seconds per km.”
These numbers are training estimates, not prescriptions. They do not set weekly mileage, session count, or recovery days.
Calculation method
VDOT is estimated from race distance and time, then converted to velocity at percentages of VO2 for each training zone. Cite: Daniels, J., Daniels’ Running Formula, Human Kinetics.
The implementation is deterministic: the same race always yields the same paces. It is still a model of intensity, not a lab VO2 test.
VDOT does not know injury, heat, or that you only run three days a week. Heart-rate zones are a different language — use the heart-rate calculator if that is how you train. Nothing here is a coaching service.
Frequently asked questions
What is VDOT?
An index of endurance fitness that Jack Daniels estimated from race performance. This calculator uses it to set training paces, not as a medical VO2 max.
What paces come from a 20-minute 5K?
About VDOT 50. Easy running is slower than 4:00/km 5K pace. Open the tool with 5K and 20:00 to see the full bands.
Are these paces a training plan?
No. They are intensity estimates from one race. They do not prescribe how often to run intervals or how long easy runs should be.
Should I use my goal marathon time or a recent 5K?
Use a recent race that represents current fitness. A goal time you have not run will invent a VDOT you do not have yet.