7-Zone vs 5-Zone Training: Why FTP-Only Zones Hold You Back
Every power-based training system starts with zones. And almost every one defines them as percentages of FTP.
Zone 2 is 56-75% of FTP. Threshold is 91-105%. VO2max is 106-120%. You’ve seen these numbers a hundred times. They’re in every training book, every app, every coach’s spreadsheet.
The problem? They’re averages. And your body is not average.
How the 5-zone model works
The Coggan model — the most widely used — defines five (sometimes six or seven) zones as fixed percentages of Functional Threshold Power:
| Zone | Name | % FTP |
|---|---|---|
| 1 | Active Recovery | <55% |
| 2 | Endurance | 56-75% |
| 3 | Tempo | 76-90% |
| 4 | Threshold | 91-105% |
| 5 | VO2max | 106-120% |
These percentages come from research on populations of trained cyclists. They work as rough guidelines. For many athletes, they’re “close enough.”
But close enough leaves performance on the table.
The problem with percentages
Two cyclists. Both have an FTP of 280W.
Cyclist A has a high VLaMax (0.55 mmol/L/s). They produce lactate quickly, burn through glycogen fast, and their aerobic threshold is lower relative to FTP. Their real “Zone 2 ceiling” is around 58% of FTP, not 75%.
Cyclist B has a low VLaMax (0.30 mmol/L/s). They’re metabolically efficient, produce lactate slowly, and their aerobic threshold is higher relative to FTP. Their real “Zone 2 ceiling” is around 82% of FTP.
If both follow the standard 75% FTP cutoff for Zone 2:
- Cyclist A is training too hard. Their “easy” rides are actually tempo effort for their metabolism. They’re accumulating glycolytic stress instead of building aerobic base.
- Cyclist B is training too easy. They could push harder and still be aerobic. They’re leaving adaptation on the table.
Same FTP. Same zones. Completely wrong prescription for both.
What a metabolic 7-zone model does differently
Instead of deriving zones from a single number (FTP), a metabolic model uses two inputs:
- VO2max — your aerobic ceiling (how much oxygen you can use)
- VLaMax — your glycolytic rate (how fast you produce lactate)
From these two values, the Mader bioenergetic model calculates actual metabolic transition points:
- Where fat oxidation peaks
- Where aerobic threshold falls (first lactate rise)
- Where anaerobic threshold falls (lactate steady state)
- Where VO2max-limited power begins
These transitions define seven zones based on what your body is actually doing at each intensity:
| Zone | What’s happening | Defined by |
|---|---|---|
| 1 — Recovery | Below fat oxidation peak. Minimal stress. | Below FatMax |
| 2 — Endurance | Peak fat burning. Aerobic development. | FatMax to AeT |
| 3 — Tempo | Above aerobic threshold. Glycolytic contribution rising. | AeT to below AnT |
| 4 — Threshold | Lactate steady state. Maximum sustainable intensity. | Around AnT/MLSS |
| 5 — VO2max | Above threshold. High oxygen demand. | AnT to VO2max power |
| 6 — Anaerobic | Above VO2max. Heavy glycolytic contribution. | Above VO2max power |
| 7 — Neuromuscular | Maximum power. Very short duration. | Max sprint |
The key difference: the boundaries between zones are calculated from your metabolism, not from FTP percentages. Two athletes with the same FTP but different VLaMax values will have completely different zone boundaries.
Why this matters for training
Your Zone 2 might be wrong
This is the biggest practical impact. Zone 2 is where most endurance athletes spend the majority of their training time. If your Zone 2 ceiling is set too high (because FTP-based zones don’t account for your VLaMax), every “easy” ride is actually moderate-intensity. Over months, this leads to:
- Incomplete recovery between hard sessions
- Elevated chronic fatigue
- Impaired aerobic development (too much glycolytic stress)
- The classic “always tired, never improving” plateau
Athletes with high VLaMax are especially vulnerable. Their true easy pace is lower than FTP-based zones suggest.
Your threshold zone is too broad
The 5-zone model puts threshold at 91-105% of FTP — a 14% range. That’s massive. The metabolic model narrows this to the actual range where lactate production and clearance are balanced. For some athletes, this band is only 5-8% wide. Training at the wrong end of “threshold” changes the adaptation you get.
Interval targets are more precise
When your VO2max zone boundary is calculated from actual VO2max (not just “106% of FTP”), your interval targets are more accurate. You’re training the energy system you intend to train, not accidentally doing tempo when you think you’re doing threshold.
How to get metabolic zones without a lab
The gold standard is a laboratory ramp test with blood lactate sampling at each stage. This directly measures your lactate curve and identifies metabolic transitions. It costs $200-400 and gives you a snapshot for that day.
The alternative: model-based estimation from regular training data.
The Mader model can estimate VO2max and VLaMax from the relationship between your power output and heart rate during submaximal rides. It’s not a single test — it accumulates data from every ride, getting more accurate over time.
The accuracy is within ~10% of lab values for VO2max estimation. For zone prescription purposes, that’s enough to produce meaningfully better zones than FTP percentages alone.
The practical advantage: your zones update continuously. A lab test gives you zones for that month. Model-based estimation gives you zones that evolve as your fitness changes.
When 5 zones are fine
Be honest: for some athletes, 5 zones work well enough.
- If you’re new to structured training, any zone model is an improvement over training by feel alone.
- If your VLaMax is near the population average (~0.4 mmol/L/s), FTP-based zones will be reasonably close to your metabolic zones.
- If you’re doing polarized training (lots of easy + some very hard), the exact zone boundaries matter less because you’re spending little time in the middle zones.
The athletes who benefit most from metabolic zones are those who:
- Have been training for 2+ years and are plateauing
- Have an unusually high or low VLaMax
- Spend significant time in Zones 2-3 (endurance-focused training)
- Want to understand why certain intensities feel harder than the numbers suggest
The bottom line
The 5-zone model is a useful starting framework. But it’s a map drawn from population averages, not from your body. A 7-zone metabolic model uses your actual VO2max and VLaMax to calculate where your training zones really fall.
The difference is most impactful at the low end (Zone 2) and the middle (threshold). Getting these right means your easy rides are truly easy, your hard rides target the right energy system, and the hours you invest in training produce the adaptations you’re actually seeking.
Your zones should be as individual as your fingerprint. Percentages of FTP are a guess. Your metabolism is the answer.
Watts calculates your 7-zone model from regular training data using the Mader bioenergetic model. No lab test needed — your zones update with every ride as your fitness evolves.