Author Topic: FTP  (Read 3478 times)

FTP
« on: April 24, 2020, 07:03:04 am »
Not just file transfer protocol it seems but also:

Quote
FTP stands for Functional Threshold Power, which is commonly defined as the highest average power you can sustain for an hour, measured in watts.

I never thought about it until lockdown made me buy a turbo trainer.

I discovered it when Zwift told me mine had been raised, not sure what to as they didn't say. I guess about 230watts. My neighbour says that sounds too high as his is 180 Watts.

Do you know your FTP?
Sic transit and all that..

Re: FTP
« Reply #1 on: April 24, 2020, 07:11:21 am »
Mine varies with fitness. Currently 200 (or, maybe less :( ), at my most fit (over recent years since I've been able to measure) 290 ish

Re: FTP
« Reply #2 on: April 24, 2020, 07:55:28 am »
I (could, before lockdown) sustain a bit over 140W with my arms. This is using a hand crank trainer in the work gym.

Should be much higher using legs on a bike. Over 200W sounds about right for a fit cyclist who is actively training.

Academic testing suggests that arm power is about 2/3 leg. So the estimate from my 140W for arms would be 210W for legs.
<i>Marmite slave</i>

Re: FTP
« Reply #3 on: April 24, 2020, 08:13:13 am »
Me: 192W
Fboab: Much more than me.

LMT

Re: FTP
« Reply #4 on: April 24, 2020, 08:13:59 am »
I do

Re: FTP
« Reply #5 on: April 24, 2020, 08:25:35 am »
If you want to know it, measure it. There are a few different tests, I assume Zwift has at least the 20 minute one? If not, you basically pick a pace that you can sustain for 20 minutes, and then multiply the average power for that duration by 0.95. There are various refinements to do with depleting your anaerobic abilities first, but TBH, if you haven't done those sorts of tests before then pacing is likely to be your biggest problem. Also, some turbos are better than others a measuring power.

How reasonable 230W is depends on many things. If you weigh 50kg and are female, 230W would be enough to be a seriously competitive cyclist. If you are a 100kg man, not so much. Position will also have an effect - most people make less power in the TT position for example.

My lowest test was 171 when I started Trainer Road. My highest was 262, just before I damaged my foot in 2018. I've floated around 240 ish ever since, though I suspect I'm closer to 220 at the moment.

fboab

  • It's a fecking serious business, riding a bike
Re: FTP
« Reply #6 on: April 24, 2020, 08:38:14 am »
Zwift has 3 options
  • Traditional 20 minute test
  • Ramp test
  • auto demonstrate.

If Zwift is telling you yours has increased, that means you just did a 20 minute effort at a wattage 95% of which was more than what you currently have your ftp set at. it usually shows the increase though - 175 to 210, for example. It won't automagically update what you set it to, though, you have to do that yourself.

Obviously watts is only half the story. Your neighbours 180 watts might be 3W/kg if he's 60kg. If you are 75kg, your 3W/kg is 225W

Mine's 231, which if I was 55kg would be f'ing awesome. Unfortunately, I'm not.
TSS is not Total Sex Score, Chris!

Re: FTP
« Reply #7 on: April 24, 2020, 08:40:17 am »
About 250W based on the speed I can hold for a "10".  Not good enough for racing but good enough not to get overtaken much on the road.  It's never changed much over the years.  Strava, whose power figures are plucked out of the air, suggests I only use about 160W on a long flat stretch where I usually hold 22mph.  It has no idea about my position on the bike, though.
And Darkness and Decay and the Coronavirus held illimitable dominion over all.

Pedal Castro

  • so talented I can run with scissors - ouch!
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Re: FTP
« Reply #8 on: April 24, 2020, 08:56:31 am »
Most apps will estimate it from a shorter duration than 1h, e. g. 95% of your best 20' power is common. It does depend on the equipment used though so your FTP as calculated on a turbo might not be the same as your FTP as measured with a power meter on the road, or even different power meters on the same road bike could give different values particularly if comparing hub and pedal PMs.

The best use of this number is that it allows you to plan your training sessions more precisely and measure your progress. Using it to compare with other people will give you a ball park comparison but there could be a +/-50W error due to different set ups and/or calculation used. (NB +/-50 might be a little on the high side but you get the idea)

PS my FTP is 218 on my turbo set up, 227 on the road (95% of 239W for20') but my best ever 60' effort (on the road) is only 216W (all data from 2018 season, current numbers are similar)

zigzag

  • unfuckwithable
Re: FTP
« Reply #9 on: April 24, 2020, 09:11:59 am »
ftp number on its own doesn't tell the whole story, better metric for cyclists is w/kg or w/cda for flat roads.

it's good for setting your training zones and monitoring the pace.

Re: FTP
« Reply #10 on: April 24, 2020, 09:24:08 am »
Thanks for the replies.  I doubt if my smart turbo is a very reliable guide to the actual figure - it's a Turbo Muin B+, so not quite as smart as my neighbour's Wahoo Kickr - his machine's reading is maybe more accurate as we are similar in build and cycling ability.  Even so, if I can improve that will tell me something and it's a good device in other respects, think I was lucky to get it.
Sic transit and all that..

fboab

  • It's a fecking serious business, riding a bike
Re: FTP
« Reply #11 on: April 24, 2020, 09:29:02 am »
Apparently the muin are particularly bad at over reading. (sorry)
TSS is not Total Sex Score, Chris!

Re: FTP
« Reply #12 on: April 24, 2020, 09:50:29 am »
For a turbo accuracy is less important than consistency. Who cares if the number reads 5% less or 10% more than if it does this consistently on every ride. The problem comes when it reads 5% over some of the time, then 10% under, etc. Any attempt at working out your trend over time is going to be lost in the noise.

I have power meters on two bikes but don't bother with a turbo (mostly because I live in a 1st floor flat). If I want a guess at my FTP then I can use a Wattbike at the local gym. And I find a ramp test much easier than a 20 minute test. Ramp tests may not be as accurate as a 20 minute test but they're a lot easier to do physically and mentally. There's no pacing involved (you don't have to guess at what power you can maintain for 20 minutes and then attempt to do that, you simply follow the protocol until you can't go on any more). It's also shorter in time. I can warm up, do the test, cool down and be done in under 20 minutes.

This lockdown is going to be an interesting experiment as I'm off the bike completely (last ride was March 13th) although I am doing lots of running and core/leg workouts so all is not lost. I'll do a ramp test as soon as the local gym opens again and then start cycling and weekly spin classes to see how the FTP progresses.

Goals for the next few years involve rides around 100 miles (the Prudential 100 to finish off my London Classics medal, and half and possibly full Ironman which I've been talking about for years). Those distances (and longer) haven't been a problem in the past but doing them fast rather than at Audax pace will be the challenge. I'll use 200km Audaxes as training for them and try to ride them faster and with minimal stopping.

Knowing my FTP doesn't have any practical use for me really as I don't use it for any type of structured training. For my local spinning classes it's useful to know what I can hold for various durations (30s, 1m, 5m) which is all related to FTP but those can be often found with trial and error, as can intervals at the gym as I just set myself a target for, say, 3x8 intervals at 280W and then record them on the Garmin and analyse them after the fact to see if I'm improving and need to raise the target for next time (because they felt easy or HRmax is dropping and there's spare capacity).

I may just save up for a Wattbike (I'd rather have a whole exercise bike rather than a turbo, more compact and less faff, and my wife and daughter can use it). I guess there are going to be a load second hand coming on to the market once lockdown ends. If I had that I'd then be able to do some proper structured training on Zwift/TrainerRoad/BigRing/etc and do it from home (and when on boring conference calls at work) which would probably get me strong/faster a lot quicker than my own ad hoc approach.
"Yes please" said Squirrel "biscuits are our favourite things."

simonp

  • Omnomnomnipotent.
Re: FTP
« Reply #13 on: April 24, 2020, 11:34:50 am »
I tested at 219W three weeks ago, on the TR ramp test. Within 2 weeks workouts were all too easy, so I manually upped it to 229W. I haven't failed a workout yet at this setting, though they are tough.

pdm

  • Sheffield hills? Nah... Just potholes.
Re: FTP
« Reply #14 on: April 24, 2020, 11:42:25 am »
Ah, the obsessions of the lockdown! I look forward to long rides outside once the crisis passed (If we survive!)

Looking at stuff on the interweb about the Muin B+, the consensus is that its power readings are consistent but not accurate; usually over-estimating the power - worsening as it increases.
Three options, as I see it: 1. live with it and just use it as a fitness tool giving you a representative number to work with, 2. borrow a crank power meter and calibrate it for your power range or 3. if you need "accuracy" AND smart control, sell it and put the money towards a "better" unit.

2p worth:
While FTP is just a useful measure to gauge an individual's changing fitness, as a number for allow comparison between punters, I think using W/kg is more useful than straight Watts.
My FTP is usually measures around 280W which sounds a lot but that only equates to 2.9W/kg.
On my current trainer, a Kickr Core (allegedly accurate to 2%), the results are the same as on a Wattbike I previously used in the gym.
I tend to use the 20 minute test though I have noticed that some clever online systems like Zwift and BigRingVR do an FTP calculation for you based on your power curves on longer rides. I don't push as hard on these rides as in a bespoke test so my results are lower, around 240-260W. (2.5-2.7 W/kg)
IMHO, for the average fittish non-competitive cyclist, anything between 2 and 3 W/kg is quite acceptable!

Re: FTP
« Reply #15 on: April 24, 2020, 12:13:48 pm »
Apparently the muin are particularly bad at over reading. (sorry)

No worries, as long as I can keep leaving Usanians trailing, I don't mind.  (I masquerade as a Canadian, I don't think they like me.)
Sic transit and all that..

Re: FTP
« Reply #16 on: April 24, 2020, 12:28:49 pm »
I tested at 219W three weeks ago, on the TR ramp test. Within 2 weeks workouts were all too easy, so I manually upped it to 229W. I haven't failed a workout yet at this setting, though they are tough.
Which plan are you on? I think the first build plan is basically supposed to feel easy.

I've not been doing a plan for a while as I've had a variety of niggling injuries, I've jus left my FTP at 236 where it was when I last tested and ridden ad-hoc 30-45 minutes stuff with low IF. I'm in for a shock when I Ramp test next (will have to wait until my WFH desk doesn't screw up my back)...

simonp

  • Omnomnomnipotent.
Re: FTP
« Reply #17 on: April 24, 2020, 12:44:42 pm »
I tested at 219W three weeks ago, on the TR ramp test. Within 2 weeks workouts were all too easy, so I manually upped it to 229W. I haven't failed a workout yet at this setting, though they are tough.
Which plan are you on? I think the first build plan is basically supposed to feel easy.

I've not been doing a plan for a while as I've had a variety of niggling injuries, I've jus left my FTP at 236 where it was when I last tested and ridden ad-hoc 30-45 minutes stuff with low IF. I'm in for a shock when I Ramp test next (will have to wait until my WFH desk doesn't screw up my back)...

Sweet spot base mid volume, with some modifications. I'm doing the Tuesday VO2max workouts from Sweet Spot Base II instead of whatever sweet-spot workout.

My ramp-test score of 219W was slightly higher than I expected, I'd manually set 215W. I had a fairly long break in training before the ramp-test, and I would expect some early gains as there are generally long-term changes to muscles as a result of training, it's not like starting from the beginning.

Rides I've found particularly hard since the FTP bump are a 90-minute over-under workout (McAdie) and Mills (2m VO2max repeats). Yet to fail anything, but I would not be surprised to test below 229W. 7 more workouts to recovery week...

S2L

Re: FTP
« Reply #18 on: April 24, 2020, 01:31:16 pm »
Haven't bothered with a 20 minute test in years... just don't like indoor setups and it's very difficult to replicate outdoors, if you don't live in the Alps.

However, Garmin Connect extracts some numbers for me and apparently on occasions I have done 20 minutes at 230 W... but that is by no means my absolute best (road junctions, maybe a slight descent etc...)

My best guess is that I am somewhere around 240-250 Watt (3.5-3.6 W/kg).

I have done 4:30 minutes at 330 Watt  (4.8 W/kg), which for me is a more interesting number, as I don't really have the opportunity to go full on for 60 minutes, so FTP is of no real use as an indicator.

If I try, I can generally get in top 1% on any Strava segment, unless it's pan flat and requires peloton riding, or it's regularly visited by the Tour of Britain

Re: FTP
« Reply #19 on: April 24, 2020, 01:51:35 pm »
I have done 4:30 minutes at 330 Watt  (4.8 W/kg), which for me is a more interesting number, as I don't really have the opportunity to go full on for 60 minutes, so FTP is of no real use as an indicator.
That's a strangely specific time. Did you run out of hill or something? ;)
If you want to go beyond FTP, the most common I've seen are 5 second, 1 minute and 5 minute power (as well as FTP). That's the 4dp Sufferfest setup, but you can work it out from any power/duration tool.

S2L

Re: FTP
« Reply #20 on: April 24, 2020, 02:01:37 pm »

That's a strangely specific time. Did you run out of hill or something? ;)


Yes, up Edge hill in Warwickshire
Hills are the only place where I get it all out... I don't seem to be able to churn out > 300 Watt on the flat for more than a few seconds, so as tests they are pretty pointless... also the road gradient keeps changing, so it's difficult to focus and top up the power when needed.

I've also done 550 Watt (8 w/kg) for 20 seconds on a short steep climb, which might or might not say anything meaningful.

You give me a 10% climb and I can really get some good numbers out

fboab

  • It's a fecking serious business, riding a bike
Re: FTP
« Reply #21 on: April 24, 2020, 02:02:40 pm »
I just typed all my power curve figures and then realised the numbers are only of any interest to me and my Race Director1.

#wankystats

1: I do actually have one. She sends me messages while I'm racing, all pro-like.  ;D
TSS is not Total Sex Score, Chris!

Re: FTP
« Reply #22 on: April 24, 2020, 02:19:23 pm »
I just typed all my power curve figures and then realised the numbers are only of any interest to me and my Race Director1.

#wankystats

1: I do actually have one. She sends me messages while I'm racing, all pro-like.  ;D

Do you get a virtual team car with a megaphone ?

fboab

  • It's a fecking serious business, riding a bike
Re: FTP
« Reply #23 on: April 24, 2020, 02:25:36 pm »
In my head I do.

What I mostly get is "YOU GOT THIS" "GO GO GO" "AWESOME POWER GIRL" "SPRINT NOW IT'S ALL YOURS"

It's all in CAPS LOCK so I reckon, yes, megaphone all the way.
TSS is not Total Sex Score, Chris!

Re: FTP
« Reply #24 on: April 24, 2020, 03:46:17 pm »
My view, like some others is that it doesn’t matter a big lot as long as you consistently use the same setup, so that you can see variations.
To measure it accurately you need a calibrated power metre ( Wattbike or similar) and ideally ride for an hour! That’s what it says on the tin - power you can hold for 1 hour.
In Wattbike classes we found that some people got hung up on getting the biggest figure they could; using a ramp test or a 3 minute test. Particularly on the ramp test they would go beyond the indicated stopping point. This led to them being unable to effectively perform power- based training.
Ultimately FTP is a guide, not an achievement.