FTP cycling: what it is and how to measure it without fooling yourself

A power meter gives you watts, session after session. To do something with them, you need a starting point: your FTP. It is what sets your training zones and lets you track your progress from one season to the next.

The problem is that FTP is often presented as a simple truth: "95% of your best 20 minutes." It is a tracking marker, not an exact measurement. Here is how to get it, what the studies say about its limits, and how to use it.

FTP, in one definition

The concept comes from Allen and Coggan, authors of Training and Racing with a Power Meter. Holding a maximal effort for an hour is exhausting and hard to repeat. That is why a shorter version exists: in theory, FTP60 is estimated as 95% of the average power from a 20-minute time trial, called FTP20 (Borszcz et al., 2018).

FTP gives you a reference for your zones. Riding at 60% of your FTP is not the same workout as riding at 100%. Without a reference, you don't know whether your "easy" effort is really easy.

The 20-minute test, step by step

This is a field method, not a lab measurement. The steps below come from coaching practice. What the studies say about it comes in the next section.

1. Choose your setup: an indoor trainer or a flat road where you can ride without stopping, with the same power meter you always use.
2. Warm up gradually, then start the effort fresh. Coaches advise against testing when you are tired from a heavy week.
3. Start at a steady pace for 20 minutes. Starting too hard usually means slowing down later on.
4. Note your average power for the 20 minutes.
5. Multiply by 0.95.

Example: you hold 240 W on average for 20 minutes. Your estimated FTP is 240 × 0.95 = 228 W.

You can run the calculation and get your zones directly here:

Other protocols exist, such as the ramp test, where power goes up in steps until exhaustion. Each one gives its own value: an FTP from one protocol cannot be compared directly with an FTP from another.

What the studies say

The test is repeatable. Gough et al. (2025) followed 22 trained cyclists, all men, with a familiarization session. Average power from the 20-minute test was very consistent from one attempt to the next (r = 0.94).

But it does not predict one hour. In the same study, the time held at 95% of FTP20 (a power just below your estimated FTP) averaged 42 min, with a 17-min gap between cyclists. Only 6 of the 22 participants got within 10 min of the full hour.

Sitko et al. (2022) reached the same conclusion: the time held at the FTP estimated with the Allen and Coggan method stays under one hour, and it is longer for higher-level cyclists. So don't use this FTP as an equivalent of your maximal power for 60 minutes.

The 0.95 factor is not universal. Sitko et al. (2023), with 120 cyclists at four performance levels, show that the coefficient depends on level: 0.96 for professionals, instead of a single 0.95.

What about the lactate threshold? This is the highest power at which blood lactate stays stable (the MLSS). In 2018, Borszcz et al. found that, for the same cyclist, FTP20, FTP60, and another threshold method could differ by up to 60 W. In 2019, the same team concluded that trained cyclists can use FTP as a practical alternative for estimating MLSS. So use your FTP to set zones and track your fitness, not as an exact physiological threshold.

It has practical value. In 11 moderately trained male cyclists, FTP20 relative to body weight was linked to time in a 47 km (29 mi) marathon mountain bike race, while VO2max was not (Sørensen et al., 2019). The sample is small and all male, so these results are not proven for women, beginners, or older cyclists.

Mistakes that skew your FTP

Most errors come from the protocol, not from your fitness level.

• Starting too fast: you may fall apart in the second half and underestimate your FTP.
• Testing tired: avoid a hard session the day before.
• Changing gear: a different power meter, pedals, or trainer means your watts are no longer comparable.
• Mixing methods: comparing today's ramp test with a 20-minute test from three months ago makes no sense.
• Asking it to say more than it does: an FTP of 228 W does not mean you can hold 228 W for an hour.

Keep the same method and the same power meter every time. What matters is comparing your own tests. KILYO reads the sessions from your watch and tracks volume, consistency, and heart rate, to help you see whether you arrived fresh for your test.

W/kg benchmarks

To compare two cyclists, divide FTP by body weight. This gives relative FTP in W/kg. Allen and Coggan provide these benchmarks, as cited by Sørensen et al. (2019):

These are rough guides, not official standards. No federation or scientific society defines FTP. They help you place yourself, not judge yourself.

What you can do at your next session

1. Pick your protocol: the 20-minute test or another one, but the same each time.
2. Note your conditions: indoor trainer or road, power meter used, how fresh you felt.
3. Test fresh, after an easy day.
4. Calculate your FTP (× 0.95) and also keep the raw 20-minute average power.
5. Set your zones based on this value. If your efforts "at threshold" start to feel easier, it is reasonable to retest.

• ✓Same power meter and protocol as your last test
• ✓An easy day the day before
• ✓A steady effort from start to finish, no fast start

Written with the help of AI.