Polarised or Pyramidal: What 2026 Science Says on Zones
The question comes back every time the season changes: how to split time across training zones to get the most out of 10 hours a week. The polarised model has the appeal of simplicity, easy or very hard, nothing in between. The pyramidal model sounds more reasonable, more at the bottom, less in the middle, a sharp peak at the top. In 2026, a fresh research summary from Arturo Casado, PhD, puts the matter to rest: neither model wins everywhere. That is the most important conclusion of the season.
What actually separates the polarised model from the pyramidal one
Both models describe what percentage of training time is spent in three intensity zones:
- Zone 1 (Z1): below the first lactate threshold (VT1/LT1). Conversational pace, easy effort.
- Zone 2 (Z2): between the first and second thresholds (LT1 and LT2). A pace that cannot be held for long, but is not all-out either.
- Zone 3 (Z3): above the second threshold. Lactate tolerance work, VO2max repeats.
Polarised (POL): lots of Z1, almost nothing in Z2, a decent amount of Z3. Pyramidal (PYR): lots of Z1, moderate Z2, little Z3.
Why these are not the “zones” shown on a Garmin, an important note
Anyone training with a Garmin, Wahoo or TrainingPeaks likely sees five zones based on the model developed by Dr Andrew Coggan, the researcher behind the FTP concept and co-author of Training and Racing with a Power Meter from the early 2000s. That model splits intensity by percentages of FTP and maximum heart rate, treating Zone 4 as the lactate threshold.
The three-zone model used in scientific research (Seiler, Casado, Filipas) is built on two physiological ventilatory thresholds, VT1 and VT2. It is a different cut of the same physiology:
| Five-zone model (Coggan / Garmin) | Three-zone model (research) |
|---|---|
| Z1 Recovery | Z1 (easy, below VT1) |
| Z2 Aerobic base | |
| Z3 Tempo | Z2 (grey zone, between VT1 and VT2) |
| Z4 Lactate threshold (FTP) | |
| Z5 VO2max and above | Z3 (above VT2) |
When research says to avoid Z2 in the polarised model, it means zones 3 and 4 on a watch: half-marathon pace, threshold intervals, “sweet spot” work. It does not mean avoiding easy aerobic base, which sits inside Z1 of the research model and is exactly what belongs there. Seiler himself uses the three-zone model in research for simplicity, but works with athletes using five zones, because they give more precision when planning sessions.
Figures from a study by Sellés-Pérez et al. (Journal of Sports Science and Medicine, 2019) on age-group athletes racing the half-iron distance, IRONMAN 70.3 (1.9 km swim, 90 km bike, 21.1 km run), commonly called a “half”, make this concrete:
| Group | Z1 | Z2 | Z3 |
|---|---|---|---|
| POL | 84.5% | 4.2% | 11.3% |
| PYR | 77.9% | 18.8% | 3.3% |
The Z2 gap is stark: nearly a fifth of training time in the pyramidal group, barely a mention in the polarised one.
What the research shows at the middle distance
The same study found an interesting relationship: time spent in Zone 2 correlated with a better race result among age-groupers at the half-iron distance. In other words, in the 70.3 group, the pyramidal distribution beat the polarised one on race outcome.
That is counterintuitive for anyone who listens to podcasts about the “Norwegian model” and the Iden and Blummenfelt brothers. But the logic is simple: a 70.3 puts an athlete at near-threshold intensity (Z2) for four to five hours. Training that includes plenty of Z2 prepares an athlete better for exactly that.
Casado, on episode 695 of the That Triathlon Show podcast, discusses a study by Filipas et al. (Scandinavian Journal of Medicine & Science in Sports, 2022), in which a 16-week periodised plan, the first 8 weeks pyramidal and the next 8 weeks polarised, produced better running results than either model held for the full cycle. The improvement was mainly in 5k time and speed at lactate threshold; VO2max changes did not differ significantly between groups.
What this means in practice, periodisation instead of doctrine
The research synthesis available through 2026 points to a phased approach:
General phase (base period, November to January). Pyramidal distribution. Plenty of Z1 (around 75 to 80%), a meaningful chunk of Z2 (15 to 20%), little Z3 (3 to 5%). This builds aerobic capacity, movement economy and threshold.
Specific phase (February to April). Shift toward polarised. Keep Z1, reduce Z2 to roughly 5 to 8%, add deliberate Z3 blocks, Norwegian threshold sessions, VO2max repeats. This is when 30/30 intervals start to make sense.
Race phase (May to September, depending on the calendar). Mixed, maintaining all systems while the specific demands of the race take over. For a half, return to more Z2 in the week before the start. For a full-distance event, hold polarisation with long Z1 sessions and short Z3 sparks.
Recovery phase / off-season. Everything in Z1 with one sharp stimulus a week. Not the time for a plan.
What about the 80/20 model
The popular 80/20 model (80% easy, 20% hard) comes from Stephen Seiler’s research into intensity distribution among elites, and is a simplified version of the polarised model. It works well for runners training at very high volume, 15-plus hours a week. For an age-group athlete training 8 to 10 hours a week, the problem is different: the 80% “easy” training often is not easy at all. It ends up in a grey zone, too hard for recovery, too weak for progress.
For an age-grouper, what matters more than choosing between the polarised and pyramidal model is this:
- Keeping Z1 genuinely in Z1. The test: it should be possible to hold a conversation in full sentences.
- Controlling Z3. A real VO2max repeat is one you would cut off your own arm to end.
- Not dragging every session up to a perceived effort of 7 out of 10. That is the road to overtraining without progress.
What to use when building toward a 70.3
A concrete outline to work from:
- November to January: pyramidal. Plenty of long Z1 (bike 2 to 3 hours, run 60 to 90 minutes), one Z2 session a week (for example 4×8′ at threshold), one short Z3 session (for example 6×3′ VO2max).
- February to April: shift toward polarised. Two Z3 sessions a week (Norwegian double threshold, classic 4×4′ VO2max), Z2 limited to brick sessions and specific tests. Everything else in Z1.
- May to September: race specificity. Two weeks before a 70.3, bring back Z2 (race-pace repeats: on the bike 2×30′ at 85% FTP, on the run 3×3 km at half-marathon pace).
- October to November: everything in Z1 plus one sharp stimulus a week.
There is no sacred percentage. There is a phase, a race, and an athlete’s own recovery. The 2026 scientific consensus: be periodised, not dogmatic.
Verdict
Polarised versus pyramidal is a false argument if the choice has to be made once and for all. The best adaptations come from a plan that shifts the intensity distribution across the season: pyramidal in the base period, polarised in the specific period, mixed at the race. Casado and the 2026 research say the same thing good coaches have said for years, just with numbers behind it now.