Endurometry
These are the sources Endurometry calculators actually rely on. Each entry says what we use it for and which calculators depend on it. We only list sources that are used in a calculation or in the methodology — not general reading.
Unit conversion and race distances
Guide for the Use of the International System of Units (SI) — NIST Special Publication 811
A. Thompson, B. N. Taylor · National Institute of Standards and Technology (NIST) · 2008
How Endurometry uses it: Exact definition of the international mile (1 mile = 1,609.344 m), used for every kilometre ↔ mile conversion of distance, pace and speed.
Book of Rules — Competition and Technical Rules (road races)
World Athletics · current edition
How Endurometry uses it: Standard road-race distances — marathon 42.195 km, half marathon 21.0975 km — used as distance presets, worked examples and the cutoff calculator’s course length.
Race prediction
Athletic Records and Human Endurance
Peter S. Riegel · American Scientist · 1981
How Endurometry uses it: Power-law race scaling T2 = T1 × (D2/D1)^k, with k = 1.06 (standard) and k = 1.10 (conservative for longer targets).
Oxygen Power: Performance Tables for Distance Runners
Jack Daniels, Jimmy Gilbert · Oxygen Power · 1979
How Endurometry uses it: Oxygen-cost and %VO2max equations used to compute VDOT from a known race, to predict another distance, and to convert a fraction of VDOT into a training pace.
Training methodology
Daniels’ Running Formula (training intensities / VDOT paces)
Jack Daniels · Human Kinetics · 2021
How Endurometry uses it: Published training-intensity fractions of VDOT (Easy, Marathon, Threshold, Interval, Repetition) used as the zone bounds on the training-pace calculator and the intensity table on the pace-chart generator.
Heart rate
The effects of training on heart rate: a longitudinal study
M. J. Karvonen, E. Kentala, O. Mustala · Annales Medicinae Experimentalis et Biologicae Fenniae · 1957
How Endurometry uses it: Heart-rate reserve method HR = (HRmax − HRrest) × % + HRrest, used for Z1–Z5 on the heart-rate calculator and the optional HR table on the training-pace page.
Age-predicted maximal heart rate revisited
Hirofumi Tanaka, Kevin D. Monahan, Douglas R. Seals · Journal of Applied Physiology · 2001
How Endurometry uses it: Age-predicted max HR ≈ 208 − 0.7 × age. Default estimate on the heart-rate calculator and the only age estimate on the training-pace page, unless a measured max is entered.
Physical activity and the prevention of coronary heart disease
S. M. Fox, J. P. Naughton, W. L. Haskell · Annals of Clinical Research · 1971
How Endurometry uses it: The familiar HRmax ≈ 220 − age rule of thumb, offered on the heart-rate calculator as a comparison to Tanaka and Gellish.
Longitudinal modeling of the relationship between age and maximal heart rate
R. L. Gellish, B. R. Goslin, R. E. Olson, A. McDonald, G. D. Russi, V. K. Moudgil · Medicine & Science in Sports & Exercise · 2007
How Endurometry uses it: Quadratic age estimate HRmax ≈ 191.5 − 0.007 × age², offered as a third option on the heart-rate calculator.
Energy cost
ACSM’s Guidelines for Exercise Testing and Prescription — metabolic equations (running)
American College of Sports Medicine · Wolters Kluwer · current edition
How Endurometry uses it: ACSM running metabolic equation VO₂ = 0.2v + 0.9v×grade + 3.5 and the 5 kcal per litre O₂ conversion, used for gross and net calories and for treadmill ↔ outdoor pace.
A 1% treadmill grade most accurately reflects the energetic cost of outdoor running
A. M. Jones, J. H. Doust · Journal of Sports Sciences · 1996
How Endurometry uses it: Empirical finding that 1% treadmill grade at the same displayed speed best matched still-air outdoor cost. Cited as the common indoor 1% convention; the converter itself equalises ACSM VO₂ and does not keep speed constant.
Age grading
Endurometry approximate open-class road age factors (5-year bins, linear interpolation)
Endurometry · 2026
How Endurometry uses it: Endurometry’s own 5-year age-factor knots (linear interpolation, one table for all distances and both sexes). Not official WMA tables; documented on the methodology page. Also used to stretch average-finish seed times with age.
Body mass and time
Endurometry approximate race-time scaling t ∝ mass^0.67 (allometric rule of thumb)
Endurometry · 2026
How Endurometry uses it: Endurometry’s t ∝ mass^0.67 rescaling. An allometric rule of thumb, not a Daniels table and not ACSM. Documented on the methodology page.
Average finish times
Endurometry recreational seed baselines (age-30) scaled by Endurometry age factors; Top/Bottom 20% are 0.85× / 1.18× sketches
Endurometry · 2026
How Endurometry uses it: Recreational age-30 seed times and 0.85× / 1.18× sketches used by the average-finish calculator and, until live samples dominate, by /average-times/ articles.
Endurometry Calculation Methodology
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