Cycling power zones explained
Power zones turn one number, your FTP, into clear targets for every kind of session. Here is what each zone means and how to use them without overthinking it.
What power zones are
Power zones are bands of effort, each defined as a percentage of your FTP. Because they're relative, two riders with very different fitness can follow the same workout: "Zone 2" means the right intensity for each of them.
| Zone | Name | % of FTP | At FTP 250 W | How it feels |
|---|---|---|---|---|
| Z1 | Recovery | ≤ 55% | ≤ 138 W | Very easy, chatting |
| Z2 | Endurance | 56–75% | 140–188 W | All day, steady |
| Z3 | Tempo | 76–90% | 190–225 W | Moderately hard, focused |
| Z4 | Threshold | 91–105% | 228–263 W | Hard, ~1 hour max |
| Z5 | VO2max | 106–120% | 265–300 W | Very hard, 3–8 min |
| Z6 | Anaerobic | > 120% | ≥ 303 W | All-out, under 2 min |
The watt ranges above are for an FTP of 250 W. Yours move with your FTP, which is why an accurate test matters.
What each zone trains
- Z1 Recovery: spinning the legs after hard days. Barely a training stimulus, and that's the point.
- Z2 Endurance: the base of almost every training plan. Builds aerobic fitness and fat burning, and you can ride here for hours.
- Z3 Tempo: comfortably hard. Useful in moderation, but easy to overdo (see below).
- Z4 Threshold: right around FTP. Intervals here raise the power you can sustain.
- Z5 VO2max: 3 to 8 minute efforts that push your maximum aerobic capacity.
- Z6 Anaerobic: short, all-out efforts for sprints, attacks and steep ramps.
How to balance your training
Many endurance coaches follow a polarized approach: roughly 80% of your training time easy (Z1 to Z2) and 20% hard (Z4 and above), with only limited time in Z3. Zone 3 feels productive, but it's hard enough to tire you and not hard enough to drive the biggest high-intensity gains, so a week that's mostly tempo often leaves you tired without getting much faster.
Between Z3 and Z4 sits sweet spot, around 88 to 94% of FTP: a time-efficient way to build threshold power when you only have a few hours a week.
Power or heart rate?
Power responds instantly, so it's the better target for intervals. Heart rate lags behind by up to a minute, and it drifts upward with heat, fatigue and dehydration. Use power for the targets and heart rate as a check on how your body is coping.
Ride it, don't just read it.
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