FTP and power on the bike: what they are and how to use them (beginner's guide)

A power meter is the most precise tool for training on the bike: it tells you how much force you are really producing, regardless of wind, climbs or fatigue. FTP is the number almost everything starts from.

What is FTP

FTP stands for Functional Threshold Power: the highest power, in watts, you can sustain continuously for about an hour. It is a reference for building training zones and tracking progress over time.

How to estimate it

The most common method is a 20-minute test at steady maximum effort after a good warm-up: FTP is estimated as 95% of the average power over those 20 minutes. Do the test rested, at an even pace, and don't start too hard. Ramp tests on a trainer or training platforms also exist.

Power zones

Once you have an FTP you can calculate zones as percentages: active recovery under 55%, endurance 56-75%, tempo 76-90%, threshold 91-105%, VO2max 106-120%. The figures are indicative and vary between methods. The endurance zone is the one that builds your base: read the guide to zone 2.

How much do you really need it?

For an amateur it isn't essential, but it helps you avoid going too hard on easy days and too easy on hard days. For long rides and gran fondos, power lets you pace your effort on climbs. To make the most of it pair it with a good bike computer.

A numerical example

If your average power over the 20-minute test is 200 watts, your estimated FTP is 190 (95%). From there the endurance zone, between 56 and 75%, runs from about 106 to 142 watts. These are example figures: your own value depends on you and on how you did the test.

Mistakes to avoid

The most common is testing while tired, or starting too hard and fading. Another is comparing your watts with other people: what matters is your own trend over time. Repeat the test about every 6 to 8 weeks, in similar conditions. If you have health problems or have not trained for a while, avoid maximal tests without medical advice.

How to start

A pedal power meter or a bike computer compatible with power meters are the first useful purchases.

Don't start with too many numbers: pick a goal and use power to keep it in check.