FTP testing is the colonoscopy of cycling. You know you should do it regularly. You keep putting it off because it’s unpleasant. When you finally do it, you wonder why you waited so long.

Functional Threshold Power—roughly the power you can sustain for an hour—is the reference point for training zones. Get it wrong and your training zones are wrong. Sweet spot becomes threshold. Recovery becomes tempo. Everything shifts.

But the test itself? Twenty minutes of maximal effort. No drafting, no coasting, just sustained suffering until you see spots.

There are ways to make it better. Not enjoyable—I won’t lie to you—but better.

Quick Answer

The standard 20-minute test works, but pacing is everything. Start at 95% of your target and build. Test in similar conditions each time so results compare. Alternative protocols like the ramp test are easier to execute but may not suit all riders.

Why Your FTP Probably Isn’t What You Think

Most cyclists either overestimate or underestimate their FTP.

Overestimation: That 300-watt FTP from last year’s peak form? If you haven’t tested since, it’s likely lower. FTP decays faster than we admit.

Underestimation: You tested when tired, or paced badly, or the trainer wasn’t calibrated. Your zones are set too low, and hard workouts feel too easy.

Either way, your training suffers. Accurate testing matters.

The 20-Minute Protocol

The classic test: ride as hard as you can sustain for 20 minutes. Take 95% of the average power. That’s your estimated FTP.

Why 95%? Because most people can hold slightly higher power for 20 minutes than they can for 60 minutes. The 5% adjustment approximates the difference.

Warmup (20 minutes)

Don’t skip this. A proper warmup means you can access full power when the test starts.

• 10 minutes easy spinning (50-60% FTP)
• 3 x 1-minute builds to threshold, 1-minute easy between
• 5 minutes easy
• Start the test

The Test (20 minutes)

First 5 minutes: Start conservative. About 95% of your target average. The mistake is going out too hard and blowing up at minute 12.

Minutes 5-15: Settle into a rhythm. Check power every few minutes but don’t obsess. This should feel like “hard but sustainable.”

Final 5 minutes: Empty the tank. If you have anything left at minute 18, you went too easy.

Cooldown (10 minutes)

Easy spinning. Your legs will hate you. This helps them hate you slightly less tomorrow.

Pacing: The Part Everyone Gets Wrong

The first two minutes feel easy. You’re fresh, motivated, ready to prove something. So you push too hard.

Minute 15 arrives, power drops, and you spend the final five minutes watching your average fall. Classic blowup.

Better approach: Start under what you think you can hold. If you’re targeting a 260 average, start at 250. You can always add power late. You can’t recover from starting too hard.

Negative splits—riding the second half faster than the first—produce better results than positive splits for most people.

The Ramp Test Alternative

Don’t want to suffer for 20 straight minutes? The ramp test offers an alternative.

Protocol: Start at low power, increase every minute by a fixed amount (usually 20 watts), ride until you can’t maintain the target. The test ends when you fail.

Calculation: Take your best 1-minute power from the test, multiply by 0.75. That’s your estimated FTP.

Pros:

• Shorter overall suffering (usually 10-15 minutes of real effort)
• Easier to execute—no pacing decisions
• Less psychological barrier

Cons:

• Rewards anaerobic power more than the 20-minute test
• May overestimate FTP for diesel-type riders
• May underestimate FTP for sprinters

I’ve used both. The ramp test consistently puts my FTP about 5 watts higher than the 20-minute test. Which is “right” depends on what I’m training for.

The 8-Minute Test

Two 8-minute efforts with 10 minutes rest between. Average the two, take 90%.

Good for: Riders who fall apart mentally in longer tests. Breaking it into chunks makes the suffering more manageable.

Drawback: Two hard efforts means pacing both well. If you blow the first one, the second is compromised.

Testing Conditions Matter

FTP isn’t a fixed number. It varies with conditions.

Indoor vs. outdoor: Most people test lower indoors. Heat, boredom, position differences all contribute. I test about 5-7% lower on the trainer.

Fresh vs. fatigued: Test at the end of a recovery week, not mid-training block.

Fed vs. fasted: Eat normally. Don’t try to test on empty.

Time of day: Your power varies throughout the day. Test at the same time each time.

Calibration: Make sure your power meter is calibrated before testing. Zero offset before every test.

Consistency: Test in similar conditions each time. If you always test indoors, keep testing indoors. Comparing indoor and outdoor tests is comparing apples to slightly different apples.

How Often to Test

Every 4-8 weeks during focused training. More often is unnecessary—FTP doesn’t change that fast. Less often and your zones drift from reality.

Some coaches suggest testing at the start and end of training blocks. Others prefer mid-block checks. I test at the end of recovery weeks, when I’m fresh and the result reflects actual fitness rather than accumulated fatigue.

What the Number Tells You

FTP is one number. It’s useful, but limited.

What it captures: Your threshold power—the intensity where lactate production and clearance balance.

What it misses: Endurance, repeatability, sprint power, power at altitude, ability to surge. All things that matter for racing.

FTP is a training tool, not a fitness score. A 300 FTP doesn’t mean you’ll beat a rider with 280 FTP. Context matters.

When the Test Goes Wrong

Bad tests happen. Recognizing them saves you from training with wrong zones.

Signs of a bad test:

• Power dropped more than 10% from start to finish (blowup)
• You stopped early because of non-physical reasons (boredom, interruption)
• Equipment issues (power spikes, dropouts)
• You were sick or unusually fatigued

If the test went wrong, don’t use the number. Rest a few days and retest.

Making It Suck Less

Some things that help:

Music: Create a 20-minute playlist that builds to your hardest songs at minute 15.

Visual focus: Stare at one number (time remaining, not power). Watching power fluctuate drives you crazy.

Distraction: Some people do better with a podcast or show. Others need silence. Know yourself.

Course selection: If outdoors, pick a long gradual climb or flat road without stops. Indoor trainer removes variables but adds heat and monotony.

Company: Testing with someone else helps. Suffering together is slightly easier.

What to Do With the Results

Once you have your FTP, set your training zones. Common models:

Zone	Name	% of FTP
1	Active Recovery	<55%
2	Endurance	56-75%
3	Tempo	76-90%
4	Threshold	91-105%
5	VO2max	106-120%
6	Anaerobic	>121%

Your training platform probably calculates these automatically once you enter FTP. Just make sure the number is right.

The Mental Game

FTP tests measure physical capacity, but mental state affects the result by 5-10%.

Positive mindset: “I’m going to hold this power” vs. “I don’t think I can do this”—the self-talk matters.

Familiarity: The first few times you test, you’re learning the protocol. Results improve as execution improves.

Fear: Some riders test below true FTP because they’re afraid of the suffering. The test requires going deep. If you always save something for the end, you’ll never know your real limit.

The Bottom Line

FTP testing is unpleasant. Do it anyway. The 20 minutes of suffering gives you accurate training zones for months.

Start conservative, build through the effort, and compare tests done in similar conditions. The number won’t define you as a cyclist—but it will help you train smarter.

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Personal testing protocol refined over 4 years. Find what works for you and stick with it.