Trainer FTP and real life FTP

kawaspresso
kawaspresso Posts: 106
edited January 2019 in Indoor training and turbo forum
Hello,
I have a different FTP on Zwift than on outdoor rides. My real life FTP for 20min is 270w, but on Zwift I'm not able to push more than 230w for 20min.
Am I alone or is it like that for everyone ?
Thanks

Comments

  • AK_jnr
    AK_jnr Posts: 717
    Mine is around 20 watts lower inside. Thats with the same PM.
  • MiddleRinger
    MiddleRinger Posts: 678
    My FTP is slightly higher on the trainer as I can hammer harder without worrying about traffic or crashing. Also do a lot of time on the turbo so have kind of adapted. My shorter term power (1 min and shorter sprints) is higher outdoors.

    And your FTP is not 20 min power, rather that minus 5 percent.
    ~ ~ How fast is fast enough? ~ ~ ~ ~ Tempo Cyclist - Tasmania ~ ~
  • Alex99
    Alex99 Posts: 1,407
    kawaspresso wrote:
    Hello,
    I have a different FTP on Zwift than on outdoor rides. My real life FTP for 20min is 270w, but on Zwift I'm not able to push more than 230w for 20min.
    Am I alone or is it like that for everyone ?
    Thanks

    Are you using the same power measurement hardware?

    There are some real reasons why your indoor power may differ e.g. cooling, changed pedal stroke, motivation
  • kawaspresso
    kawaspresso Posts: 106
    Alex99 wrote:
    kawaspresso wrote:
    Hello,
    I have a different FTP on Zwift than on outdoor rides. My real life FTP for 20min is 270w, but on Zwift I'm not able to push more than 230w for 20min.
    Am I alone or is it like that for everyone ?
    Thanks

    Are you using the same power measurement hardware?

    There are some real reasons why your indoor power may differ e.g. cooling, changed pedal stroke, motivation

    Motivation is not a problem when racing on Zwift, but it's annoying to not be able to do my intervals trainings at the same intensity than outdoor.
    I use a 4iiii powermeter with a Garmin edge 810, always using the same shoes and pedals. Maybe I should buy a fan, but as it's not summer, there are no store selling them...
  • jgsi
    jgsi Posts: 5,062
    It is always harder going outdoors for me.. wattage is usually down from a Zwift race session where you dont have any drag/adverse road conditions/block winds to contend with.
    Only the very short intervals of 2/5 seconds get higher on the road.
    I really dont see where it becomes a hindrance.
    Different disciplines.
  • charlie_potatoes
    charlie_potatoes Posts: 1,921
    kawaspresso wrote:
    Maybe I should buy a fan, but as it's not summer, there are no store selling them...

    Good selection available at screwfix
    "You really think you can burn off sugar with exercise?" downhill paul
  • jmm434
    jmm434 Posts: 18
    I find that my FTP is also much higher on the road. Maybe being able to really rock the bike around and get after it allows for higher FTPs. My sprint power is also higher on the road. Or it totally could be mental...when you're moving you just want to keep going faster! On the trainer it is just a number, not speed. Not as fun!
  • lazy_pete
    lazy_pete Posts: 1
    Hi, I'm consistently 9% worse indoors
  • SJH76
    SJH76 Posts: 191
    jmm434 wrote:
    I find that my FTP is also much higher on the road. Maybe being able to really rock the bike around and get after it allows for higher FTPs. My sprint power is also higher on the road. Or it totally could be mental...when you're moving you just want to keep going faster! On the trainer it is just a number, not speed. Not as fun!

    I agree with this especially. If I'm sprinting out on the road, I have a fixed point of focus i.e the finish line and that's all I'm thinking of. On a trainer I just seem to count the seconds until it's over and they can feel like a lifetime if im really pushing hard. Cos of that, I do tend to drop my intensity sooner than out on the road.
  • N0bodyOfTheGoat
    N0bodyOfTheGoat Posts: 6,057
    My best 20min power effort this year was less than 5W lower indoors, albeit measured by Direto indoors and 4iiii outdoors, ~292 vs 295 iirc.

    Maybe the fact I rarely use a fan for turbo sessions in the kitchen is a factor, after a while my body adapted to riding relatively hard in the heat.

    But having started using the turbo again recently, it was a shock riding without a fan in temps up to ~25C, including a 20min effort of 291W.
    ================
    2020 Voodoo Marasa
    2017 Cube Attain GTC Pro Disc 2016
    2016 Voodoo Wazoo
  • diplodicus
    diplodicus Posts: 722
    I too have a lower indoor figure.

    I use 3 different figures. Outside (tt) highest. Indoor normal position lower. Indoor in tt position lowest.

    I'm not posting the figures as they seem so much lower than everybody else :oops: :lol:

    Edit, all measured with the same hub based power meter
  • Typical Analytical
    Typical Analytical Posts: 165
    Indoor != Outdoor
  • pamplemoose
    pamplemoose Posts: 85
    Glad it's not just me! My indoor ftp is about 10% lower than it is outdoors (using the same powermeter pedals). I guess it's mostly down to the fact that outside I'm generally not overheating as much.
  • diplodicus
    diplodicus Posts: 722
    This might explain some of the differences

    https://www.trainingpeaks.com/blog/adju ... or-riding/
  • kingstongraham
    kingstongraham Posts: 28,154
    diplodicus wrote:
    This might explain some of the differences

    https://www.trainingpeaks.com/blog/adju ... or-riding/

    The fixed position makes some sense.

    On the rear wheel resistance, would riding uphill not essentially be the same as rear wheel resistance? If you stop pedaling, you stop moving and there is resistance around the pedal stroke.
  • diplodicus
    diplodicus Posts: 722
    Possibly

    I think my differences are probably the temperature effects.
    I am not sure all the article affects everyone, food for thought though?
  • pamplemoose
    pamplemoose Posts: 85
    diplodicus wrote:
    Possibly

    I think my differences are probably the temperature effects.
    I am not sure all the article affects everyone, food for thought though?

    Same here. I live in a tiny terrace house so have to do my training in the living room. My wife would complain if I turned the heating off for the duration of my training and I've yet to buy a fan to keep me cool. I could certainly observe the 'cardiovascular drift' mentioned in the article. By the midway point of my session my HR was 20 BPM higher when putting
    out the same watts as earlier in the session and sweat was cascading off me. This was with all the windows open! :shock:
  • dannbodge
    dannbodge Posts: 1,152
    pamplemoose wrote:
    diplodicus wrote:
    Possibly

    I think my differences are probably the temperature effects.
    I am not sure all the article affects everyone, food for thought though?

    Same here. I live in a tiny terrace house so have to do my training in the living room. My wife would complain if I turned the heating off for the duration of my training and I've yet to buy a fan to keep me cool. I could certainly observe the 'cardiovascular drift' mentioned in the article. By the midway point of my session my HR was 20 BPM higher when putting
    out the same watts as earlier in the session and sweat was cascading off me. This was with all the windows open! :shock:

    Jesus. I'd die without a fan/cold room.
    My "Shed" where I turbo train is outside with no heating and generally around 10-15degC at the moment. No doubt it will drop to single digits when the cold weather comes.
    I can last about 10 mins warm-up before I have to turn my 18" fan on and even then I still sweat buckets (I've got a thermometer in there and by the end of my sessions I raise the temp by a good 5-10'C) and that's just wearing normal padded shorts and a base layer.....
  • kingstongraham
    kingstongraham Posts: 28,154
    pamplemoose wrote:
    diplodicus wrote:
    Possibly

    I think my differences are probably the temperature effects.
    I am not sure all the article affects everyone, food for thought though?

    Same here. I live in a tiny terrace house so have to do my training in the living room. My wife would complain if I turned the heating off for the duration of my training and I've yet to buy a fan to keep me cool. I could certainly observe the 'cardiovascular drift' mentioned in the article. By the midway point of my session my HR was 20 BPM higher when putting
    out the same watts as earlier in the session and sweat was cascading off me. This was with all the windows open! :shock:

    Buy a fan.

    You'll notice the difference from even a desk one pointed in the right direction. Being in cool air isn't the same as air flow.
  • N0bodyOfTheGoat
    N0bodyOfTheGoat Posts: 6,057
    edited December 2018
    NitrousOxide wrote:
    My best 20min power effort this year was less than 5W lower indoors, albeit measured by Direto indoors and 4iiii outdoors, ~292 vs 295 iirc.

    Maybe the fact I rarely use a fan for turbo sessions in the kitchen is a factor, after a while my body adapted to riding relatively hard in the heat.

    But having started using the turbo again recently, it was a shock riding with out a fan in temps up to ~25C, including a 20min effort of 291W.

    Having averaged 305W over ~19min45secs (the complete Col de Soller in Vitugo) a few weeks ago on the turbo, an impromptu effort after tweaking my saddle position resulted in new PB of 306W over 20mins just before dinner this evening on RoadGrandTours' Stelvio Pass.
    https://www.strava.com/activities/2040614454

    Not a bad way to be ending the year, having just turned 45, especially after my sorry hangover state two days ago. :)

    Using a newly purchased Honeywell fan for the last month, typically doing power zone 4-6 intervals every other day in that warm kitchen.

    Edit: Managed a further improvement on Zwift earlier, despite those dips on the "Mountain 8" course where I dared not use a bigger gear than 34/16, managing 308W average for my best 20mins. For some reason, Zwift decided to tell me my estimated FTP was now 294W, which is more than 95%.
    ================
    2020 Voodoo Marasa
    2017 Cube Attain GTC Pro Disc 2016
    2016 Voodoo Wazoo
  • jgsi
    jgsi Posts: 5,062
    I'm 64, and if I put my mind to it, can output just under 300watts for 20 minutes... that being a 'test' in September.
    I'm not fussed by the numbers as such apart from dropping to a race weight of 76kg for 2019 season. racing at 84kg is seriously no fun.
    I mean if Cippo can juice up and register a Wiki weight of 75kg, I'll have some of that.
  • EBEB
    EBEB Posts: 98
    I think it depends on duration. For a full hour I think I would get pretty similar numbers. Sprints & short intervals are higher outdoors, particularly those less than a few minutes. Over a 20 minute period I suspect I could get slightly higher outdoors, but most places I can think of don’t have 20 minutes continuous riding so I’ve never tested. The formula for ‘normalised power’ is obvious nonsense.
  • Typical Analytical
    Typical Analytical Posts: 165
    Not what you're looking for, but FTP doesn't matter. Just train at the maximum power that you can sustain across all intervals. For sub-threshold work, use cardiac drift or a percentage of the power you are routinely able to produce over long intervals. Indoors vs outdoors doesn't matter. Do what you need to do indoors and do what you need to do outdoors.

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