You have an FTP, you have a heart-rate trace, and you have a power meter throwing numbers at you on every pedal stroke. But if every ride ends up being "hard enough", those numbers aren't working for you. Power zones exist to fix exactly that: to turn raw data into an actual training decision.

Why train by zones instead of by feel

Feel lies. On a fresh day a climb seems easy; on a tired day the same effort feels brutal. Power, on the other hand, is objective: the watts you produce are the watts you produce, here and now, regardless of how your legs feel. Cycling power zones take that number and split it into bands, each of which stresses a different physiological system.

The goal isn't to have seven numbers on your head unit. The goal is that each band has a job: one builds your aerobic base, another raises your threshold, another develops your VO2max. Training by zones means deciding what you want to improve and then hitting the right band for it — instead of forever riding in the no-man's-land between easy and hard.

Where the zones come from: your FTP

Almost every power model is anchored to a single reference number: your FTP (Functional Threshold Power), the power you can hold for roughly an hour. Every zone is then calculated as a percentage of that figure. This is exactly why your FTP needs to be measured properly and updated as your fitness shifts: if the anchor is wrong, every zone built on top of it is wrong too. If you're not yet sure how to establish yours, start with our guide on how to calculate your FTP and then come back here.

The most widely used framework is the six (or seven) zone model proposed by Andrew Coggan. It became the standard because it's straightforward to apply and it covers the entire spectrum of effort, from easy recovery spinning all the way to a flat-out sprint.

The six (or seven) Coggan zones, one by one

Here are the bands, expressed as a percentage of your FTP, and — more importantly — what each one actually trains:

  • Zone 1 — Active recovery (< 55% FTP). Very light spinning. It doesn't build fitness; its job is to loosen the legs, speed up recovery after a hard session, and keep you moving on easy days.
  • Zone 2 — Aerobic endurance (56–75% FTP). Conversational pace, where you can still talk in full sentences. This is the heart of your base: it develops your aerobic engine, fat-burning efficiency, and capillary density. Most of your volume should live here.
  • Zone 3 — Tempo (76–90% FTP). Demanding but sustainable, the classic "race pace" of long climbs. Useful, but also the zone amateurs hide in far too often: comfortable to do, yet not very productive if it becomes your only intensity.
  • Zone 4 — Threshold (91–105% FTP). Right around your FTP. This is where you raise the power you can hold for a long time, which directly moves your gran fondo "cruising speed". Hard but controlled.
  • Zone 5 — VO2max (106–120% FTP). Short, intense efforts that push your ability to consume oxygen to its limit. These are the intervals that make your legs burn; they raise the ceiling on your potential.
  • Zone 6 — Anaerobic capacity (121–150% FTP). Very short, very hard efforts, from around 30 seconds to a couple of minutes. They train lactate tolerance and punch: short walls, sharp accelerations, the decisive surges.
  • Zone 7 — Neuromuscular power (> 150% FTP). The pure sprint, a few seconds flat out. Muscle recruitment and explosive force. Here duration matters more than the exact percentage of FTP.

One honest caveat: the boundaries between zones aren't walls. They're guideline bands, and your body doesn't abruptly switch gears at exactly 76%. Treat them as a compass, not a cage.

How to actually use zones to build sessions

Knowing the zones isn't enough on its own; the value comes from combining them into sessions with a purpose. A few concrete examples:

  • Aerobic long ride: two to three hours almost entirely in Zone 2, resisting the temptation to drift into Zone 3 on every climb. This builds the base.
  • Threshold work: three or four blocks of 8–12 minutes in Zone 4, with easy Zone 1 recoveries between them. This raises your FTP over time.
  • VO2max intervals: repeats of 3–5 minutes in Zone 5, with recovery roughly equal to the length of the effort. This pushes your aerobic ceiling.
  • Anaerobic / sprint work: short bursts in Zone 6, well spaced out and with plenty of recovery, to prepare you for surges and short walls.

The key principle is that most of your time should sit low (Zones 1–2) and a clear minority should sit high (Zone 4 and up). Zone 3, on its own and repeated endlessly, is the most common trap: it feels like serious training, but it's precisely that "grey zone" that's too hard to recover from and too easy to drive real adaptation.

Common mistakes with zones

Zones only work if you genuinely respect them. The most frequent stumbling blocks:

  • A wrong FTP. An inflated FTP makes every zone too high: your threshold work turns into disguised VO2max efforts, and you end up cooked all the time.
  • Constantly overshooting. Pushing "just a bit harder" in your threshold reps doesn't make them better; it changes the stimulus entirely. If the plan says Zone 4, stay in Zone 4.
  • Living in Zone 3. The middle ground is comfortable but unproductive when it becomes your only intensity.
  • Ignoring duration. The very top zones (6–7) are defined more by time than by percentage: what matters there is how many seconds you can hold, not the exact watt figure.

Where Per Pro fits in

Knowing what each zone trains is only half the job. The other half is deciding which zones to touch this week, in what order, and for how long — based on your goal and the time you actually have. That's exactly what Per Pro does: it takes the methodology of real World Tour coaches — the way they structure zone-based sessions to bring professionals to the start line — and rewrites it around your real life, so your rides always have a clear job instead of just being "hard enough". You can see how it works at per-pro.com.

Key takeaways

  • Power zones turn raw watts into training decisions: each band stresses a different physiological system.
  • They're calculated as a percentage of your FTP, so an accurate, up-to-date FTP is the foundation of everything.
  • Coggan's 6–7 zone model runs from recovery (Z1) to the sprint (Z7), passing through endurance, tempo, threshold, VO2max and anaerobic work.
  • Spend most of your time in Zones 1–2 and a clear minority from threshold up; Zone 3 is the trap.
  • Respect the zones: no inflated FTP, no overshooting, and for the top zones remember that duration is what counts.