The 20-minute FTP test — Allen & Coggan protocol

What FTP actually means

FTP — Functional Threshold Power — is the average watts you can hold on the bike for one hour, right at the edge of what is sustainable. It is the single most useful number a coach pins on you and a clean way to track form across a season.

Why measure it: training zones are derived from FTP. Without that number, any structured plan is guesswork — one rider's zone 2 is another's zone 4.

The Allen & Coggan 20-min test

The standard reference protocol — straightforward, repeatable, fits in a Tuesday evening.

1. Warm up 15–20 min — easy zone 2 plus three 1-minute openers at zone 5 effort.
2. Easy spin 5 min — let HR drop and the legs come back.
3. Test 20 min — the highest steady-state effort you can hold for the full block. No surges, no fade. Average watts is the only number that matters.
4. Cool down 10 min — easy.

FTP = 20-minute average power × 0.95.

Why 0.95

Twenty minutes is not an hour. Most riders can hold roughly 5% more power for 20 minutes than for 60 because the anaerobic system contributes meaningfully at that duration. Multiplying by 0.95 strips that contribution back out, giving an approximation of the one-hour effort that defines threshold.

The training zones

Once FTP is set, every zone follows. Coggan defined seven, from Z1 (recovery) to Z7 (neuromuscular sprints):

Zone 2 is the base. 70–80% of an advanced amateur's training volume should live here — easy 1.5–3 hour rides, conversational HR, you can speak full sentences. It is boring and exactly why riders who do it get faster six months later.

Zone 4 is threshold work. Classic 3×10 or 2×20 intervals sit here. Per minute of effort, these produce the biggest fitness gain — and accumulate fatigue fastest.

How often to re-test

Every 4–6 weeks during structured training. Every 8 weeks in the off-season. More often and you cannot see the signal through the noise — the body needs time to adapt before another data point is worth taking.

Alternatives to the 20-min test

• Ramp test (TrainerRoad) — 25-minute pyramid, +6% power per minute. Shorter, easier to pace, but underestimates FTP for riders with strong anaerobic capacity.
• Kolie Moore protocol (40–60 minutes by feel) — the most accurate of the three but requires pacing experience. Save it for race prep, not every block.

Never compare FTP figures across protocols — they measure slightly different things. Pick one, stick with it for the season.

What to do next

With FTP known, the next investment is the tool. Direct-drive trainers deliver the cleanest indoor power numbers — see the ThinkRider trainers in our catalog. A crank- or pedal-based power meter is the second step once the trainer pays for itself.

Source: Allen, H. & Coggan, A. (2019). Training and Racing with a Power Meter, 3rd ed. VeloPress. Plus Hunter Allen's Performance Manager Chart work at TrainingPeaks.