Question 1

What is FTP?

Accepted Answer

FTP (Functional Threshold Power) is the highest average power in watts you can sustain for roughly an hour on the bike. It's the single most important number in cycling — most training programs, power zones, and race pacing decisions are built around it.

Question 2

How is FTP estimated from a 20-minute test?

Accepted Answer

The standard protocol: warm up, then ride all-out for 20 minutes. Your FTP is approximately 95% of your 20-minute average power. The 5% discount accounts for the fact that you can push harder for 20 minutes than you could for a full hour.

Question 3

What is watts per kilogram (W/kg)?

Accepted Answer

W/kg is your FTP divided by your bodyweight in kilograms. It's the key metric for climbing and relative performance. A 70 kg rider with 280W FTP has the same W/kg as a 90 kg rider with 360W — they'll climb at similar speeds despite very different power numbers.

Question 4

What W/kg is considered good?

Accepted Answer

For men: 2.0-3.0 is a recreational rider, 3.0-4.0 is a solid amateur, 4.0-4.5 is cat 3/4 racer territory, 4.5-5.5 is cat 1/2, and 5.5+ approaches pro. For women subtract roughly 0.5 W/kg at each tier. These are FTP-based; sprint and 5-min W/kg show different distributions.

Question 5

How often should I retest FTP?

Accepted Answer

Every 4-8 weeks if you're training consistently. More often during fast adaptation phases (new to training, returning from layoff), less often when plateaued. Many riders also use a ramp test or 8-minute test, which correlate well with the 20-minute method.

Question 6

Does FTP change with bodyweight?

Accepted Answer

Your absolute FTP (watts) mostly reflects training state. Your W/kg also responds to bodyweight changes — losing fat raises W/kg without requiring more fitness. For climbers, W/kg improvements often come faster from losing 2-3 kg of body fat than from adding 20 watts of power.

FTP / Watts per Kg
Cycling Power Zones

FTP & Watts per Kilogram Calculator

FTP and Watts per Kilogram Explained

Why W/kg Matters

Running a 20-Minute Test

Formula

W/kg Classification (Male)

Frequently Asked Questions