Authority · the models explained
Training Philosophies & Zone Models
The people behind the models: Coggan, Friel, Seiler, Maffetone, Daniels and Lydiard. How their zone systems differ and when to use each.
Most training-zone systems trace back to a handful of coaches and scientists. They disagree on the details, number of zones, what anchors them, how hard to go, but agree on the fundamentals: build a large aerobic base, anchor intensity to a measurable threshold, and keep easy days easy. Here is who built each model on this site, and where to use it.
Andrew Coggan, Power zones & FTP
Exercise physiologist; co-author of Training and Racing with a Power Meter.
Anchor cycling training to Functional Threshold Power (FTP) and a seven-zone model expressed as percentages of it.
Coggan's framework made power-based training mainstream. FTP, roughly the power you can hold for an hour, anchors zones from active recovery (≤55% FTP) to neuromuscular power (>150%), with Sweet Spot (88–94%) as a high-efficiency training band. It also introduced metrics like Normalized Power, Intensity Factor and Training Stress Score.
Joe Friel, LTHR zones
Endurance coach; author of the Training Bible series.
Set heart-rate zones from lactate-threshold heart rate (LTHR) measured by a 30-minute time-trial field test.
Friel popularised threshold-anchored heart-rate zones for amateurs, with a simple, repeatable field test: the average heart rate of the final 20 minutes of a hard 30-minute solo effort. His sport-specific zone tables for cycling and running remain a default for coaches worldwide.
Stephen Seiler, Polarized / 80/20
Sports scientist who quantified how elite endurance athletes train.
A three-zone intensity-distribution model: about 80% easy, 20% hard, with little time in the middle.
Seiler's research found that across rowing, running, cycling and skiing, elite athletes converge on a polarized distribution split at the two lactate turnpoints. The insight is less about exact zone borders than about how much time is spent low versus high intensity.
Philip Maffetone, MAF / aerobic base
Endurance coach and clinician; creator of the 180 Formula.
Build a deep aerobic base by training almost entirely at or below a heart-rate ceiling of 180 minus your age (adjusted).
Maffetone's MAF method is deliberately conservative, prioritising fat metabolism, health and injury prevention over short-term speed. Progress is tracked with the MAF Test: pace at a fixed aerobic heart rate should improve over weeks. It is influential in ultra-endurance and triathlon.
Jack Daniels, VDOT & pace zones
Legendary running coach and exercise physiologist; author of Daniels' Running Formula.
Derive every training pace from a single fitness number (VDOT) calculated from a recent race result.
Daniels combined VO₂max and running economy into VDOT, then defined five training paces, Easy, Marathon, Threshold, Interval and Repetition, as fractions of it. One race result yields a complete, individualised pace plan. His Daniels–Gilbert equations underpin most modern running-pace calculators.
Arthur Lydiard, Aerobic base & periodisation
New Zealand running coach whose methods reshaped distance running.
Build a huge aerobic base first, then layer hill strength and speed in distinct training phases.
Lydiard's periodised approach, months of high-volume aerobic running before sharpening, produced Olympic champions and influenced generations of coaches. His emphasis on aerobic development at controlled effort is a direct ancestor of today's Zone 2 and polarized thinking.