First, that's just a number I'm tossing out, there's no "We" involved. And I'm being generous. Dunno why. You certainly haven't earned it.

The CP model is a guess based on your inputs. Given the paucity of your inputs, it's worthless. If you go out and do a ride that kicks your AWC up to 20 kJ from the 13 it's currently at, your CP will probably drop to the 230W range.

I went back and looked at the best efforts power curve for the entire year. There was very little difference in power at the durations I used to calculate critical power.

And what are those durations?

Note also that's number 6 on the Coggan link you're so fond of, way down the scale towards least accurate. And by number 4 the result is already inaccurate enough to be almost useless.

Again, no matter how hard you try to avoid it, it's simple. What's the best average power you've been able to hold recently for 60 minutes? That's your FTP. Everything else is a guess, some better than others, but a guess nonetheless.

Has anyone else actually played with the CP FTP calculator mentioned?

You put in 3min and 12min power.

Critical Power Calculator | Two Wheel Blogs

Based on power curve of some recent segments, I get 306 watts FTP estimate.

Doing the same with two of the points from the curve that Dunbar provided gives 279. So maybe the calculator is in question.

Some of you with established FTP should give it a try and let us know if it's reasonably close.

OP. You are correct in all the links you site. But your application of the information provided in those sites is inaccurate.

If you are having trouble talking while riding, even at a low effort, that means you have low fitness, i.e. a low base, and are working harder than you seem to think you are working. That's just human physiology.

It doesn't seem to make a difference. I tried the Monod protocol 3/12, 1/10, 5/10 and they all arrive the same number +/- 5w or so. And I wouldn't call NP from a 1h race useless for most people. Race efforts are arguably one of the most accurate ways to determine FTP since it's hard to push yourself that hard in training.

Critical Power Calculator | Two Wheel Blogs

http://www.cyclingpowerlab.com/MonodCriticalPower.aspx

Those are all short intervals, where it's easy for your anaerobic capacity to skew the results upward.

And using NP for an hour race to estimate FTP really is worthless. It doesn't need to be all that inaccurate to be so, either. For a 300W FTP, z3-z5 are what? About 30-35W each? If your FTP estimate is 10% off, you're going to be completely in the wrong zone when training. If the FTP is set anything over 10% too low, z5 VO2max workouts become z3/4 sweet spot workouts. And you'll only do 5-8 minute intervals - at a power level you should be able to hold for over an hour without too much difficulty. If your FTP is set just 10% too high, you won't be able to complete any real z4 or z5 workouts at the prescribed power levels.

The fact that you're only doing 2 ten-minute intervals is informative. You can't do four or six of them at those power levels because your anaerobic capacity gets depleted and your aerobic capacity (FTP) isn't high enough to sustain you for that many intervals.

I live in West Los Angeles which means 20 minute uninterrupted stretches of road are extremely hard to find. I did get a suggestion for a 20 minute climb that I'm going to start using even though I don't enjoy climbing.

You shouldn't be looking down at your power numbers in a 1 hour crit or road race. The whole point is to evaluate the power numbers after the race to see what you can do in a highly motivated race situation. FTP is also self-correcting like you alluded to. If they feel too easy, you raise the target power. If you blow up before the end of the interval you drop target power.

Don't start making excuses. Stick with the script.

Really? because... ya didn't.

I get it, it's probably hard for somebody from Oklahoma to understand.

I was referring to psimet's FTP estimates based on the info posted. I've consistently said I don't think my FTP is being grossly overestimated...

how about you post actual raw data instead of snippets and formulations. like your last 50mi ride.

It is tough for us folks to understand your city ways. We're just simple people who do things like listen to good advice when its given.

You should buy a trainer and ride that to determine your FTP.

I've thought about it but good fluid trainers that mimic road feel are ~$300. Hard to justify spending that much just to test FTP.

So buy an inexpensive magnetic. :rolleyes:

CycleOps Fluid Trainer

Buy that.

"You should buy a car so you don't have to walk"
"I would but Bentley's are just so expensive"

Cheap mag trainers have very little inertia which means they don't simulate riding conditions on the road. Translation - unless you spend a lot of time riding them they suck for testing FTP.

Make sure you have the gearing to do that climb at your normal cadence. If you normally pedal in the 90 rpm range, for example, and you have to do that climb at 65 rpm your results will not reflect your FTP.

Power numbers are a training tool used to improve race results. I'd say the only point power numbers in a race have is to provide another perspective that can be used to set power levels for training, not to find out what you can do in a race. Because in a highly motivated race situation, you do what you can do, power numbers be damned. (Not totally true - I do look at my numbers during races, but not to figure out if I can go harder. I look at 'em to prevent me from blowing up and getting myself dropped before the final sprint.)

How much money have you spent on all other things that your using to train with power?... And now how much are those things worth if you have a bad estimation of your FTP?...

It's not really "just to test FTP" either. It is an excellent training tool especially if you live in an area where you can't find 20 minutes of uninterrupted road.

It's not just to test FTP.

Trainer time is great for LONG uninterrupted stretches of z2 or z3 riding that can really help boost FTP. It's insipidly boring, but it works better than outside riding, for me at least. It's hard to develop true endurance when you stop for something every few minutes.

Trainers are also great for hitting very specific power levels in z5 or z6 workouts. It's just about impossible to hold, say 400 +/- 20W for two minutes with absolutely no stops in pedaling outside. It's possible to do that on a trainer. That enables very specific training to be done that can't be easily replicated outside, if it's even possible to do outside.

And if you already have a power meter, it really doesn't matter what kind of trainer you have as long as it isn't subject to having variable resistance. As long as it's steady it'll work.

Even the best fluid trainers do a completely crappy job of simulating riding conditions on the road.

Yeah, they have a better power vs. "speed" curve. For a device that, when working properly, doesn't move at all. How "fast" you go on a trainer is like wondering what color your dog's bark is. It's kinda orthogonal to reality.