Functional Threshold Power (FTP)
FTP (Functional Threshold Power) is a practical estimate of the highest cycling power you can hold for a long time, fairly steadily, around your threshold. It is the anchor for your power zones and for the load calculation of your rides.
What is FTP?
FTP is often described as "the power you can hold for an hour", but that is a rule of thumb, not a definition: how long someone can really ride at threshold varies from person to person and from day to day. Think of FTP mainly as the anchor point against which your zones, interval targets and load scores are calibrated.
Above FTP you draw on a finite reserve that empties fast — your anaerobic (oxygen-free) reserve — and fatigue climbs hard; below FTP the effort is far easier to sustain. That is why a small error in your FTP setting is felt in every session that leans on it.
How do you find your FTP?
The best-known field test is the 20-minute test: after a thorough warm-up you ride 20 minutes all-out but evenly, and a common convention estimates FTP at about 95% of your average power. Ramp tests (steadily harder until you can’t continue) are popular too, though they lean more heavily on assumptions about your anaerobic capacity.
FTP can also be estimated without a dedicated test, from your power-duration curve: your best power over a range of durations (from minutes to an hour) from ordinary training and races. That approach does require you to go genuinely deep now and then, otherwise the curve underestimates your level.
Retest or recalibrate after a focused block of training, after a long break, or when sessions at your current zones consistently feel too easy or too hard.
How Trimetra personalises this
Trimetra derives FTP suggestions from your power-duration curve based on existing training and races, so a separate test isn’t required. Every adjustment is put to you as a suggestion and only applied once you agree; the suggestions activate only when there is enough recent, reliable power data.
Frequently asked questions
Can you determine your FTP without a test?
Yes. Your FTP can be estimated from your power-duration curve: your best power outputs over different durations from normal training and races. The one condition is that you occasionally go really deep, otherwise the curve underestimates your level.
What is a good FTP?
A bare wattage says little: 250 watts means something completely different at 60 kg than at 90 kg. Look at power per kilogram (W/kg) instead, and above all at your own development over months. For orientation, recreational cyclists often sit between 2 and 3 W/kg around threshold.
How often does your FTP change?
After a focused training block your FTP can rise noticeably, and after a long interruption it drops. So re-test or recalibrate periodically — especially when sessions in your current zones consistently feel too easy or too hard.
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