About Endurometry

Who

Endurometry is maintained by a runner who also writes software; their current marathon personal best is 3:43:53. We are not a sports-science laboratory, a coaching business, or a medical practice. Nobody here is presented as a doctor, licensed coach, or published scientist.

Why

The site exists so you can get a pace, a split table, or a published-model estimate without hunting through a wall of ads. Calculators stay free in the browser. Optional Pro only unlocks extras such as plan history and print/export.

How we ship a method

For each calculator we pick a documented method (a definition, a published model, or an Endurometry approximation we label as such), implement it, check the output against reference examples, test empty / negative / extreme inputs, then publish. When a method changes, the calculator, the methodology page and the in-page notes are updated together.

Evidence chain: calculator → methodology → sources. Legal limits: disclaimer.

Models used

• Riegel power law (1981): T₂ = T₁ × (D₂/D₁)^1.06
• Daniels–Gilbert: VO₂ = -4.6 + 0.182258v + 0.000104v², with the sustainable-%VO₂max curve
• ACSM running equation: VO₂ = 0.2v + 0.9v·grade + 3.5
• Karvonen heart-rate reserve: HR = (HRmax − HRrest) × intensity + HRrest

Data notes

Age factors use an Endurometry approximation, not official WMA tables. Average finish times in the in-browser tool are a seed model, not official statistics.

How these numbers are produced

Each figure blends a published baseline model with real anonymous submissions using a shrinkage estimator: with few samples the value stays close to the baseline, and as submissions accumulate the real data takes over. Groups with fewer than 8 submissions show the baseline only.

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