[Closed] One for the roadies...what is my FTP?

Based on what you’ve written I would guess at 200-220w

It's quite common for turbo ftp to vary quite a bit from outside - usually it's lower. So you did 220 solid for 20 mins indoors, that might be 250 emptying the tank, which in turn might be 275 outside with a number on your jersey, and could be even higher on a mountain time trial. FTP is then 95% of these numbers IIRC - Sounds like you're around the 225 mark, give or take?

So it can vary quite a bit, if you mix training inside and out you might need two values.

I don't know about crank PMs but I have a bepro pedal PM which although it's well-rated as a reliable device, does seem to be a bit flattering on the climbs - dishing out bestial Watts. FTP efforts on slight inclines to work against are good, but I don't think a steep pitch will give very accurate number.

The thing about FTP is that it's a threshold. Under it, as long as you keep fuel going in you can keep going ''indefinitely" .  Above it and it becomes hard quite quickly. So trying to estimate based on a road ride can be hazardous, estimating high and being slightly the wrong side of threshold and as you say, you wouldn't be able to hold it for longer periods.

I'd say 200-220 as well.

If you head over to somewhere like Timetrialling forum, there is plenty of discussion on how FTP is NOT 95% of 20minute power.  It could be, but it's just as likely not to be.  Why not just ride for 1 hour at a hard pace, that will give you a nearer idea rather than guessing you went fairly hard for 20mins and then carried on riding and then ....

"Normalised power is roughly FTP plus 5%"

If that is correct then FTP is lower than normalised power. 220 minus 5% is 209.

Im not sure sure your ftp is 220 as you say youve never emptied the tank.  You need to do that.  You need a steady paced 20mins with nothing left after.

It’s also worth mentioning that if you decide to do a 20 minutes FTP make sure you do the prescribed 5 minute all-out pre-fatiguing (followed by 5 minutes recovery) effort first.  This reduces the anaerobic contribution to the 20 minute effort and will give you a truer estimate of your sustainable power.  I think a lot of people skip the pre-fatiguing effort to get better numbers...

Based on what you’ve written I would guess at 200-220w

Crikey thats lower than expected. FTP is meant to be lower than normalised power according to training peaks no? And if I can hold 220 for 2 and a half hours on the road normalised surely for an hour that equates to more than 220 ftp!!? Surely!!! 🙁

FYI I have regularly achieved an average of 220 actual watts during a 20 min section of a ride but that includes  downhills, and flat where I am free wheeling, on rides well over 90 min. In fact I did that today. Surely taking that as a base I must be well in excess of 200 no?

Perhaps I'm just much slower than I thought.....

I can send you a free month pass to trainer road if you want, you can do a proper ftp test then. Only way you’ll really know for sure

Rough guess I’d say 230 ish everyone’s different...the more you test the more you’ll get familiar with the process and results, the more you’ll be able to estimate your FTP with greater accuracy.

Think just do a test to be sure, this time of year I’d be testing on the turbo as most of my intervals will be indoors.

I definitely get a lower value from the turbo so will typically re-test outdoors around March when the majority of training turns to outdoors.

Don’t forget FTP is just a reference point to work off in training or racing.  If you are not using it in a planned way it’s pretty irrelevant

I can send you a free month pass to trainer road if you want, you can do a proper ftp test then. Only way you’ll really know for sure

Cheers fella thats a really kind offer, however as I know for a fact that im quite a bit lower indoors (as many are) its probably not going to give me a realistic number for outside, which is what I'm curious about. Useful for training inside as others have pointed out however as I'm not planning to do any structured training this side of chrimbo it would be wasted on me!

The question was really asked more out of interest than anything else. Will probably resubscribe to trainer road in the new year, I found that using it with sufferfest vids really added speed previously - interestingly i use to use it with a elite wheel on trainer, and my FTP was set at 300!!! Then I raced and realised it was nothing of the sort, and when I started using a stages it dropped to around 220! This was years ago however.

is a free add-on to Strava and will tell you your estimated FTP based on your best 20min effort in the last six weeks, along with some other power stats.

cricklesorg.wordpress.com is another freebie that will estimate your power, along with other useful stats like your heart rate zones and lthr.

This year, I've found the 95% 20min power ftp does not match my best power riding for a full hour over undulating terrain, ~271W vs ~255W respectively. But then the hills in Hampshire aren't that long, the longest being Bell Hill near Petersfield, riding at high power on flat and especially downhill isn't easy or even possible with 50/11 on steep descents.

Normalised power becomes more different from average power the hillier the ride, it’s taking into account that an hour of hilly riding with its associated hard efforts will have more impact on the body than an hour at steady state.

If you want a good approximation of your ftp then put aside 45mins and do a proper test on the turbo. 10 mins warm up followed by 30mins all out effort (recording the last 20mins average power). Pace it sensibly, can I recommend starting at 200w then building to 220w after ten mins. After that listen to your body for clues. Your breathing should be tipping into panting but not getting ragged. The last ten mins should be eyes shut, sweat dripping onto the floor, total focus to the task. Stop looking at the numbers and wring the very last drop out of your body.

Go on, do it! We’ve all had to at some point or other. Let us know the result. I’m going to predict 250w.

P.s. turbo might feel harder than outside but it’s safer and easier to maintain the effort. The results won’t be wildly different from outside anyway.

Isn't it the difference between the two numbers that is the most significant and worth paying attention to:

Ftp at beginning of winter training.

Ftp at end of winter training.

At least if its out by 10w it will be consistently out by 10w?

is this a game of pin the tail on the donkey ?

an awful lot of spurious numbers being thrown about.

I don't get the thing of, "my ftp is different outside to inside" sounds like bs to me, unless anyone can tell me a genuine reason why it would be different.

You have a turbo and a power meter, take a test. Its the most accurate way to get a number.

And the answer is ........ Power Meter cc. Link it to your Strava and it will estimate your FTP, 3 minute power etc from the recent rides you’ve uploaded.

Turbo power tests are great for setting figures to train with on the turbo but your looking for real world outside power.

I don’t get the thing of, “my ftp is different outside to inside” sounds like bs to me, unless anyone can tell me a genuine reason why it would be different.

Real world vs artificial 'pressure' to perform I guess. Like the difference between how long someone could hold on hanging off a pole in a lab test vs how long they could hold on over a thousand foot drop. It is very hard for most people to be able give it everything on a turbo, even if they think they are. Does not mean your FTP is different indoors, just your ability to demonstrate it is diminished.

That and maybe overcooking with heat indoors with a fan in comparison to the larger cooling effect of the airstream over your body. Less convinced about this one as you could be climbing a steep hill at slow speed in the alps in summer and be just as hot if not hotter.

FTP is meant to be lower than normalised power according to training peaks no

Not correct. Average power, not ftp, will be lower than normalised power for a ride, with the difference getting larger if the route is hilly and you smash it up the hills. It deliberately overemphasises the power output you put in over your current FTP as the 'damage' you are doing becomes exponentially more significant. Ten reps of 10 seconds sprints at 600W with freewheeling in between over ten minutes will have a far greater destructive influence than the ten minutes of riding at 100W your average would indicate you are generating.

In 'theory' in a one hour all out effort your ftp measured on a turbo or flat road will be the same as your normalised power over the same hour with a more fluctuating power output.

Real world vs artificial ‘pressure’ to perform I guess. Like the difference between how long someone could hold on hanging off a pole in a lab test vs how long they could hold on over a thousand foot drop.
That and maybe overcooking with heat indoors with a fan in comparison to the larger cooling effect of the airstream over your body. Less convinced about this one as you could be climbing a steep hill at slow speed in the alps in summer and be just as hot if not hotter.

I have just done some googling and read a few articles, as this is something I had not heard of before. It seems there are people who claim a difference in favour of outside ftp, but also quite a few that claim the reverse.

Personally I would trust my indoor ftp much more as its a more consistent controlled environment. There are just too many variables outside.

Also OP, it would be better to judge your outdoor ftp on a flat consistent stretch of road, rather than up a hill.

I thought turbo trainers generally flattered with higher numbers as

A) You could go flat out for 20min, even in the fens no road is straight enough or flat enough to let you do that consistent an effort.

B) You can actually ride on the threshold of pukeing. On the road you would fall off and get run over by a car, on the turbo you just keep turning the pedals through that last 5 minutes.

C) You're not wasting energy in your upper body, so it's all going through the power meter.

If you've just got the power meter then you need more data than just one ride. I got mine from 220 to about 280 just by realising that actually I could pedal that hard for 20min (im a fat bastard, 280 would only begin to look impressive if i lost 4 stone).

I thought turbo trainers generally flattered with higher numbers as

A) You could go flat out for 20min, even in the fens no road is straight enough or flat enough to let you do that consistent an effort.

B) You can actually ride on the threshold of pukeing. On the road you would fall off and get run over by a car, on the turbo you just keep turning the pedals through that last 5 minutes.

C) You’re not wasting energy in your upper body, so it’s all going through the power meter.

If you’ve just got the power meter then you need more data than just one ride. I got mine from 220 to about 280 just by realising that actually I could pedal that hard for 20min (im a fat bastard, 280 would only begin to look impressive if i lost 4 stone).

But....enter a 25 mile TT on a relatively flat course and get your pacing right. You have a minute man behind you you are desperate never to see, a minute man ahead of you and another ahead of that you really want to catch and your results will be published on a great big board for everyone to laugh at. The only time I have ever worked harder was in a road race trying to chase down a breakaway or in a breakaway trying to stay away on the last lap. I have passed out at the end of TTs, thrown up, had a nose bleed and even on one occasion bled out of my ears. You are right the 'lab' environment theoretically gives you the best chance to perform but the 'human' factor will always surpass that in my opinion. Your idiotic competitive juices might not flow so freely however...

I have passed out at the end of TTs, thrown up, had a nose bleed and even on one occasion bled out of my ears

Competitive !

If you want a number grab the TR free month and do the ramp test. Idiot proof as you basically ride until you can't turn the pedals anymore. Set your FTP to 220 and start pedaling. It'll only take 20 to 30 minutes depending if you far exceed the 220 watts.

It'll be close enough for outdoor use generally but if your not using it to do structured interval work it's just a number as has been said above. Mine's been static since April but I've enjoyed my rides. Back to the hard work now until next April trying to bump it up before Spring events.

Strava seems to spit out a pretty good number on the power curve if you're a premium member.

I've left my Zwfit FTP to bump itself up as and when it sees fit normally when racing.

My indoor and outdoor ftp varies. The outdoor one is normally done as part of a local 10 mile time trial where nothing is left on the table. It’s still not 100% accurate as I drop a few watts at road junctions. Indoor is lower but more consistent. I don’t think it’s really worth trying to take an estimate from power achieved on normal rides. An ftp is an evil undertaking if done properly. It’s more about your mind than your body. I don’t consider that I have given it 100% unless I’m sick at the end. I keep a bucket by me know when I’m testing.

I have just done some googling and read a few articles, as this is something I had not heard of before. It seems there are people who claim a difference in favour of outside ftp, but also quite a few that claim the reverse.

Personally I would trust my indoor ftp much more as its a more consistent controlled environment. There are just too many variables outside.

Also the physical biomechanics of pedalling the turbo are just different, there's something about how you're always intrinsically balancing the bike outside that makes a difference to your output, and how this effects its consistency. I cannot hold position on the TT bike indoors at all - find it intolerable after a couple of minutes. But I can do a 25 (ie about an hour) outside no problem - it's not what you'd call comfortable but there's no question of coming out of position.

 It’s still not 100% accurate as I drop a few watts at road junctions.

But, those few seconds of recovery are no doubt repaid with extra effort accelerating back away. If you cross the line in a condition where you would be unable to ride at the same pace any further I suspect you've got very close to your max.

Ten reps of 10 seconds sprints at 600W

600w over 10s?  Is that all?

The main reason for turbo numbers being lower is all to do with mechanics and efficiency which I don't understand completely but for example, you'll be overheating massively on a turbo, and there is a wasted economy somewhere in loss of momentum etc....  on both those counts you are working harder for less.

But, those few seconds of recovery are no doubt repaid with extra effort accelerating back away.

Conjecture. which is why a controlled FTP test indoors is always the best option if you want accuracy and repeatability.

The main reason for turbo numbers being lower is all to do with mechanics and efficiency which I don’t understand completely but for example, you’ll be overheating massively on a turbo, and there is a wasted economy somewhere in loss of momentum etc…. on both those counts you are working harder for less.

But surely indoors is more accurate. No head wind, tail wind or side wind. No coasting, no junctions, no potholes, no uphills, no downhills. No rain, no sun, no effort to keep the bike upright.

I get the overheating bit, but loss of economy I don't get. The aim in an FTP test is to keep as consistent an effort as possible is it not? I don't get how you can do that outdoors, you will put in less effort downhill (even slight gradients), more effort uphill, and are guaranteed during a twenty minute effort to stop pedalling at some point unless you are extremely lucky.

but loss of economy I don’t get

My understanding is that you are working harder through the pedal stroke(s), using more energy, glycogen and producing more heat/lactic acid this reducing the overall economy over the given period vs road e.g working harder.   Thats not to say it isn't accurate or better than the road which it is, but something changes which makes turbo'ing harder.

FWIW I can 750w average over 30s on the road, but indoors so far I can only manage 628, I've often wondered why , there are so many factors.

This is akin to "marginal gains" IMO, its small but it impacts your ability to work as hard toward the end of the effort.  There are many variations that could do the same indoors & outdoors, this is just one small set amongst many.

My understanding is that you are working harder through the pedal stroke(s), using more energy, glycogen and producing more heat/lactic acid this reducing the overall economy over the given period vs road e.g working harder. Thats not to say it isn’t accurate or better than the road which it is, but something changes which makes turbo’ing harder.

Im still unsure. If its about power output then you only work as hard as you need to to generate the watts. Resistance, drag, and any other factor will only effect how far you travel for the given power output (which is irrelevant in a test).

Its beyond my level of knowledge / will to live to discuss further, sorry Trailwagger.   I do what I'm told.

Its beyond my level of knowledge / will to live to discuss further, sorry Trailwagger. I do what I’m told.

You OK hun?

Strangely enough my turbo FTP was always much higher than my road FTP. Could never get the same watts out on a time trial probably due to micro breaks corners, gradients etc or possibly not putting enough effort in to make my ears bleed.

I always understood it that you fatigue sooner since you're working throughout the pedal stroke, so you're fresher toward the end of an outdoor test.

You OK hun?

Yep.  Sorry that may have come across incorrectly - as much as I love a discussion its entered in the realms of what I don't know, so I can't really contribute any further, sorry.

I am reading with interest though...

Yep. Sorry that may have come across incorrectly – as much as I love a discussion its entered in the realms of what I don’t know, so I can’t really contribute any further, sorry.
I am reading with interest though…

Didn't come across badly, just poking fun at the internet.

<span style="display: inline !important; float: none; background-color: transparent; color: #222222; font-family: 'Open Sans'; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; line-height: 22.4px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">I always understood it that you fatigue sooner since you’re working throughout the pedal stroke, so you’re fresher toward the end of an outdoor test.</span>

I believe this is why its bad to do an outdoor test on a hill.

Still cant manage a double quote, sigh

Slight incline probably best, helps you keep the power on.

I think which type of test you'd do best on depends on what you're used to, and your natural physiology.

Take four different tests with two different protocols:
- An indoor ramp test to establish Maximal Aerobic Power
- An indoor 20 minute test
- An outdoor 20 minute test on a flat road
- An outdoor 20 minute test on a long hill

I've done quite a few of the first three, and keep meaning to try a proper test on a hill when I'm somewhere mountainous. My experience is of getting a result about 15w higher from an outdoor 20min test or MAP derived FTP estimation (70-85% of MAP) than an indoor 20 minute test.
Interestingly this gap has dropped over the past couple of years, as I've gotten older and started focusing more on endurance racing rather than short XCO.

The outdoor test has a lot more potential for variability. Whether this is a good thing depends on your physiology. I always found I'd perform better if I could alternate between seated and standing, so my 'ideal' testing road would be a hill that goes up in gentle ramps. I also respond well to 'micro rests', like corners.
I also know people who perform better on fast flat roads; or people who can put out much more power while standing, so would perform best on a long steep hill.

However, the end goal isn't really to find the highest power you can do for 20 minutes, it's to estimate your functional threshold. So by taking micro rests or changing position a lot you're not really following a test protocol that will find an aerobic threshold. For instance, I could probably get pretty close to my max steady 20 minute power by doing 30 second efforts with short recoveries for 20 minutes. But the physiological pathways used to do this are so totally different from steady aerobic work.

Physiologically speaking the best thing to do is an hour maximal effort on a turbo or velodrome, but this would be so horrible that there'd be a significant loss of power due to lack of motivation. Plus a regular hour effort is annoying to work into a busy training plan as it causes quite a lot of stress without massive adaptation.

And if you want to win at comparing your power data with people on the internet you're best off buying a Stages.

What's interesting is that I get the impression that most posters are claiming their outdoor ftp test to be better, just because it gives them a bigger number. While bigger is better for bragging rights, for training to threshold the more accurate number will give you the greater benefits. It may well be that the smaller number is the more accurate one.

I’d say the better one was the one which closely matched your training environment.

Through winter I work off my indoor result since most of my intervals are done on the turbo and long rides with the club at weekends are social opportunities for getting the miles in.

When it’s time to come out of hibernation I’ll do an outdoor test and work off that.

I’d say the better one was the one which closely matched your training environment

Good point.. bang on the money.

I agree with @Haze as well - you should test where you'll train. The whole point of estimating your FTP is so you can structure intervals around it.

Seeing as we're on the subject though, I do find it weird how much people talk about their FTP. It's an estimate of a physiological approximation not some kind of inherent physical attribute like penis size or IQ.

Everything I have read indicates 2 key differences - one overheating, and 2, as kryton has already called out, there is a difference in pedalling mechanics due to not having a 'dead spot' when on the turbo. I've also read that the more time spent on the turbo the quicker the discrepancy drops as your muscles adapt to the slightly different pedalling action. I spend as little time on the turbo as humanly possible.

As for people saying there is no difference, perhaps for them but I can assure you for me there is and its substantial. There is a 1.6 mile hill with about a 6 % gradient at the end of my usual ride. My stages tells me i consistently put out around 250 watts for the 8 - 9 minutes it takes me to get up there - I'm puffing a bit but not exactly bleeding out my eyeballs by the end, as I've still got 8 miles to get home.

On my tacx flux I can hold 250 watts for around 5 min when fresh and I'm totally broken at the end. So basically trying much harder, when fresher, with no external distractions...and I can't get close to the same power output.

I agree that if training indoors its the indoor ftp that counts, however given I'm cycling for fun and only asking out of interest as i seem to be getting faster, doing a 20 min test indoors holds absolutely no appeal whatsoever!

Out of interest. If you’ve never done an ftp test properly indoors or out, why did you buy a power meter?

On my tacx flux I can hold 250 watts

Using the Flux’s power meter or yours?  The two will differ.

I found the most useful way of FTP testing was during a 10 TT. Granted going to be difficult to find an event this time of year but you can still ride a course and see. Ride to the course, do the 10 and then ride back, ca.30 miles all in. For me that gave a number that was relevant to where I was testing, and for training against, especially sweet spot. Only mattered in a race to be mindful of not popping. I use a crank pm and have never paid any heed to strava numbers.

I’d say the better one was the one which closely matched your training environment

I'd say the issue there is actually an issue with your training environment if it is not you race environment. Turbo training is brilliant but not a complete replacement for training where you are racing.

A bit like these esports simulation drivers having a got at really Motorsport it could be fascinating in a year or two to have some bit hitter zwift racers who have never raced for real race some elite roadies on actual tarmac and see what happens. Similarly put the roadies on zwift and see what happens to them.

I’d say the issue there is actually an issue with your training environment if it is not you race environment. Turbo training is brilliant but not a complete replacement for training where you are racing

Point was only to address the difference between outdoor and indoor training levels that I've consistently seen since riding with power, not the smaller differences I might expect to see between varying outdoor routes.

I don't TT and rarely ride to power when racing, may have a glance now and then if I'm putting in a sustained effort but mostly the race dynamics dictate how I'm riding. Data is useful for reviewing afterwards.

I've always found my FTP outside is higher than inside. Doing it in inside is like rubbing sandpaper up & down you legs till they are raw then rubbing vinegar & salt in......at least outside you're riding your bike & zooming along to take your mind off the pain! Inside there's no distractions - it's probably harder inside but pffffttt it's hard enough as it is if you do it properly!

I always found my 20 minute power was something i concentrated more on than FTP. I found its very hard to test FTP a lot of the time and could knock out a 20min effort on a trainer or wattbike week in week out. I also found FTP often doesn't translate to cycling performance in races (apart from TT's) .

Worth a read

http://biketechreview.com/index.php/performance/supply/47-base-a-new-definition

I found the most useful way of FTP testing was during a 10 TT

But there's a difference between being fast and doing a high average power, the size of which depending on the course. I.e. in an FTP test you won't be tucked right up in an aero position, you won't freewheel and tuck on descents.

I've done a lot more 20 minute tests than TTs, so I always have to remind myself (try) to be fast, not powerful. I actually wrote this on a little note stuck on the garmin last time, otherwise the instinct to pedal through corners and stand on shallow climbs kicks in.

Using the Flux’s power meter or yours? The two will differ

I use the power from the stages on the turbo so same device to measure power

Out of interest. If you’ve never done an ftp test properly indoors or out, why did you buy a power meter

Fair question. .I bought it for a number of reasons .

1-I bought it a few years ago when I was planning to do some racing, had been using trainer road alot and seen some real improvements. Then I lost motivation, my turbo was too noisy for the downstairs neighbours, and I basically became really unfit and fat

2 - I thought it would be a useful tool for pacing myself on climbs, and to be fair it is even with doing a test. I use to start off far to quickly and was dying by the end.. Im finding I'm much fresher now for similar time up hill, despite being less fit than I was 4 years ago

3 - I was interested in seeing how I improved over time

4 - and if I'm honest the main reason, I'm a tart and had a fair bit of spare cash sitting around with nothing better to spend it on. ... Do I need it, of course not, just like I don't need a 7kg race bike with carbon aero wheels given I'm never going to ever enter a road race in my life!

As I mentioned I plan to sign up to trainer road after Christmas so will do a test on trainer then as I plan to do some structured training in 2019. Found that the sufferfest and angels is the way to go as it brought on my training massively when I used it before.

Can you not just do two tests? Put them a week apart...then you will know both values.

My power meter stays on my turbo bike just for training. So I'm only intrested in the indoor turbo values

As others have said, you have to pick the power that is most relevant for what your are doing. For me, I was testing indoors at 40W less than I could hold for an hours climbing at the start of a 100 mile road race. Training rides climbing at tempo were simply too easy, trying to ride indoors  at outdoor climbing ftp was impossible. Outdoor flat ftp was between the two. Regardless of what causes it, be flexible which numbers you apply.

For suffer fest I'll be using the lower indoor numbers regardless of how low they are.

Got a few big climbs coming up in gran canaria next week but not planning to buckle myself testing my ftp on the climbs. Would be useful to know a good pace to set however as only time I ever tackled anything similar was a few alps when the stages was broken, and I set off far far to quickly and was buckled after about 2km!

I think 230 Watts will be a good tempo to climb at when out there.

Whatever your avg power is over your sensibly paced 8 minute climb knock 10% off.

I've just made that up off the top of my head but seems reasonable.

Ok, I’m gonna say it.

MTFU and do an ftp test.

Ok, I’m gonna say it.

<span style="font-size: 0.8rem;">MTFU and do an ftp test</span>

I will when I plan to start using the trainer. But at the moment I genuinely don't see the point of doing it indoors when I'm only interested in outdoor pacing. Interested to see why you think differently though.

There isn't a 20 min hill round me to do an outdoor test but apparently I can 2x8 min to get a good idea which I may do.

https://support.trainerroad.com/hc/en-us/articles/115003401846--FTP-How-it-s-Calculate

So basically I can ride up the hill, roll down, then back up again.. And x by 90%. Which will probably give me around 230 Watts if previous Exp tells me anything. I'll let you know how I get on!

I appreciate 230 watt ftp is pretty shit..but I've always wanted to reach a goal of 250, which would give me 3.5 w/kg, which I think would be respectable and pretty achievable given I've only started cycling again in April. Why do I want this figure you ask.. No reason other than personal sense of achievement.

I just genuinely think that there are too many variables in an outdoor test to make it accurate. Using a hill for testing isn’t recommended by TrainerRoad, again due to variables and the way it forces you to recruit muscle groups throughout the pedal stroke. They recommend a 20min or 2x8 min on a flat stretch of road where you can ride constantly at maximum effort.

If you keep yourself cool and avoid thermoregulation issues then indoors is going to be more accurate, however there is also the issue that you get better at doing an FTP test through experience because pacing properly for it is hard to learn initially, that’s one of the reasons why TR brought in their ramp FTP test, it takes even less time than an 8 minute test and you just warm up then follow a rising curve of power until you hit a number you can’t physically sustain, at point the test ends and you get your FTP.

https://blog.trainerroad.com/new-ramp-test-makes-ftp-testing-more-efficient-and-less-stressful/

It's worth doing a MAP (maximal Aerobic Power) test to work out your zones. This is what many professional outfits used to gauge fitness (including British cycling)

I found it was fairly accurate at measuring my 20MP and FTP.

https://cyclingtips.com/2010/01/how-to-do-a-map-ramp-test/

from MAP you can then work out zones

[img] [/img]

It’s worth doing a MAP (maximal Aerobic Power) test to work out your zones. This is what many professional outfits used to gauge fitness (including British cycling)

interesting, it looks like the MAP test is basically the same as the ramp test, that's possibly where trainer road got it. I do know that they did a lot of work to assess the accuracy vs 20 min tests and hence FTP calculation from it

I used to geek out on this stuff way too much. I was big into time trialling. Got fitter and fitter, ftp was better than most I raced against. But in a TT race,FTP is just part of the puzzle - FTP/CDa. Then got sick of it all and jack it in. Too focussed.

Don’t go on the timetrialling forum, they’re all mental and will argue for decades about the concept of FTP 😀

TrainerRoad ramp test is definitely the best approach for inexperienced testers, I would thoroughly recommend this to the OP. You can’t pace it wrong, and it only gets painful for the final 3 mins, keep turning the pedals until you really truthfully cannot do anymore.

A 10 mile TT is a good approximation, but I used to hold 105% of my FTP, so for inexperienced you’ll likely get the wrong FTP estimate. Having said that, a 10m TT is far more fun than an indoor 20 min FTP test. 20 min test is just plain horrible. Nobody wants to do that. The ramp is actually quite fun.

Another option is Xert. I had a lot of fun with this platform. You do not need to test.

Well I did a cycle today for 90 min, with the first 25 min pretty much up hill, albeit not consistently uphill. 250 watts average for 20 min of that, 270 normalised for same period. So I'm thinking 240 watts ftp doesn't sound massively off based on those numbers. Especially given I still had an hrs riding to do after.

I'd suggest your FTP was higher than 250 unless you were laid out on the side of the road at the top of the climb barely able to continue? Probably more like 95% of your normalised if not more. What does Strava suggest if you have access to the power curve? That plus a bit if mine is anything to go by.

Said it before but my ftp is set in a one hour race or 25 mile TT. That said my FTP is not overly helpful for my favourite races as I need to maintain 67% of FTP. For 12 hours.

Anyway based on that climb, you are higher than 250 I climb at my FTP and few climbs are longer than about 30 minutes. Most a lot less.