Training-Intensity Distribution (Polarized / Threshold / Pyramidal)
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How a week's training time is split across easy, moderate, and hard zones — the main models being polarized (mostly easy + some very hard), threshold (lots of moderate), and pyramidal (a tapering pyramid from easy to hard).
Detail
Training-intensity distribution (TID) describes how total training volume is allocated across intensity zones (using a simplified 3-zone scheme: Zone 1 = below LT1/VT1 [easy], Zone 2 = between the thresholds [moderate], Zone 3 = above LT2/VT2 [hard]; see Lactate Threshold (LT1 and LT2) and Heart-Rate Zones (5-Zone Model)). Three common models:
- Polarized: a large majority of volume easy (Zone 1, ~75–80%), a small amount very hard (Zone 3, ~15–20%), and minimal time in the moderate middle (Zone 2, <~10%). Often summarized as "80/20" (≈80% easy, ≈20% hard). Meta-analyses report polarized training produces greater improvements in VO2max, peak power, and time to exhaustion than threshold-dominated approaches in many trained athletes.
- Threshold: emphasizes the moderate zone, with substantial volume (>~35%) at/near threshold (Zone 2) and the rest split between easy and hard.
- Pyramidal: volume tapers like a pyramid — most easy (Zone 1), less moderate (Zone 2), least hard (Zone 3) — so it includes meaningful threshold work but still skews easy.
The recurring theme across endurance research is that most volume should be easy, with a deliberately limited dose of high-intensity work — the opposite of the "moderate all the time" pattern many recreational exercisers fall into ("the moderate-intensity trap"). The best model depends on athlete level, sport, and training phase, and programs often shift between models across a periodized season (see Periodization Overview). The easy bulk is built from zone-2/LSD work (Zone 2 Training, Long Slow Distance (LSD)); the hard minority from VO2max intervals (VO2max Intervals); threshold/pyramidal models add tempo work (Tempo / Threshold Training).
Key facts
- 3-zone scheme: Z1 below LT1, Z2 between thresholds, Z3 above LT2.
- Polarized ≈ 80% easy / ~minimal moderate / ~20% hard ("80/20").
- Threshold: emphasizes Z2 (>~35% near threshold).
- Pyramidal: tapering — most easy, less moderate, least hard.
- Consensus: keep most volume easy; limit high-intensity dose; avoid the "moderate trap."
Connections
- Zone 2 Training / Long Slow Distance (LSD) — the easy majority.
- VO2max Intervals — the hard minority.
- Tempo / Threshold Training — the moderate/threshold component.
- Lactate Threshold (LT1 and LT2) — the thresholds defining the three zones.
- Periodization Overview — shifting distribution across a season.
Sources
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Educational content only — not medical advice. Always consult a qualified professional for individualized guidance, especially around injury, pregnancy, or medical conditions.