Variables in FTP

[geoffois]

I have been doing a fair bit on the IDT, and as such did an FTP test with trainer road about a week ago, very humbling experience, managed to get an FTP of 176W (86kg).

During this period, I have been having a bit of pain in the front of my right knee and have also found I keep on creeping forward on the saddle (rather uncomfortable).

So to try remedy this, I raised the saddle by 8mm and moved the saddle forward 4mm. The ride initially felt a little weird, but I settled in nicely. Big difference in comfort! Surprisingly, my FTP has shot up to 234W. I can understand that comfort plays a role in how much power you can put down, but the jump still seems surprising. I also assume muscle recruitment will be slightly altered, and this may also play a role in force through the pedals as well as perhaps power delivery through the pedal arc.

Has anyone else noticed this jump from subtle saddle adjustments? Quite interesting how the bike fit affects the physiology of cycling.

 

 

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[ichnusa]

Very interesting

Look forward to following this thread...

[bikebloke]

I have been doing a fair bit on the IDT, and as such did an FTP test with trainer road about a week ago, very humbling experience, managed to get an FTP of 176W (86kg).

During this period, I have been having a bit of pain in the front of my right knee and have also found I keep on creeping forward on the saddle (rather uncomfortable).

So to try remedy this, I raised the saddle by 8mm and moved the saddle forward 4mm. The ride initially felt a little weird, but I settled in nicely. Big difference in comfort! Surprisingly, my FTP has shot up to 234W. I can understand that comfort  BIKE FIT plays a role in how much power you can put down, but the jump still seems surprising. I also assume muscle recruitment will be slightly altered, and this may also play a role in force through the pedals as well as perhaps power delivery through the pedal arc.

Has anyone else noticed this jump from subtle saddle adjustments? BIKE FIT  Quite interesting how A BIKE FIT affects the physiology of cycling.

 

 

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there I fixed it for you ............

[geoffois]

I had a bike fit, this was my fiddling post bike fit [emoji12]

 

 

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[gtr1]

Proper,bike fit can make a big difference. Also, you "learn" to ride FTP tests the more you do. It's about pacing yourself and the more you did it the more you understand what works for you. So the combo of the 2 could make a big difference.

['Dale]

For beginners, it often takes 3-4 FTP tests to get a reliable value

[geoffois]

Proper,bike fit can make a big difference. Also, you "learn" to ride FTP tests the more you do. It's about pacing yourself and the more you did it the more you understand what works for you. So the combo of the 2 could make a big difference.

Maybe that's the issue.

 

 

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[rudi-h]

Yes, I can imagine that 8mm can make a meaningful difference, a saddle that is 8mm too low is A LOT!

 

I also only managed to get my "optimal saddle height" once I started using my kickr.  I do mini adjustments of about 1 or 2mm at a time and compare my effort and comfort to what it was before at consistent wattage.  Sometimes I wish i could get my MTB on the kickr so that I can repeat the same exercise, but the through axle and two sets of pedals (flats & clips) doesn't help...

 

edit:  Also don't throw away how you feel on the day.  Sometimes even within one week I have a day where I can sit at 300W for 20 minutes, and the next time I feel uncomfortable holding 260.  Sleep, eating pattern, stress all that stuff plays a larger role than we like to think.

[NotSoBigBen]

Yes, I can imagine that 8mm can make a meaningful difference, a saddle that is 8mm too low is A LOT!

 

I also only managed to get my "optimal saddle height" once I started using my kickr.  I do mini adjustments of about 1 or 2mm at a time and compare my effort and comfort to what it was before at consistent wattage.  Sometimes I wish i could get my MTB on the kickr so that I can repeat the same exercise, but the through axle and two sets of pedals (flats & clips) doesn't help...

 

edit:  Also don't throw away how you feel on the day.  Sometimes even within one week I have a day where I can sit at 300W for 20 minutes, and the next time I feel uncomfortable holding 260.  Sleep, eating pattern, stress all that stuff plays a larger role than we like to think.

 

Does it not make sense to copy your road setup (seat height and fore/aft position) on your MTB?

[J Wakefield]

Can I ask what Powermeter you are using please?

[geoffois]

I'm just using the wahoo kickr snap. Warm up plus spindown before every session.

 

I find the whole physiology and the variables at play fascinating. I can't think of a more interesting sport to study, power is measurable, contact points are essentially static, thus all variables are outside the rider/bike interface(unless altered, but then variances as a result are measurable). Certainly has tempted me to go back to varsity and do an Msc in the sports physiology of cycling.

 

 

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[Furbz]

i have trouble putting the same power out on a indoor trainer as i do on the road.

just putting it out there...

[Barend de Arend]

I'm just using the wahoo kickr snap. Warm up plus spindown before every session.

 

I find the whole physiology and the variables at play fascinating. I can't think of a more interesting sport to study, power is measurable, contact points are essentially static, thus all variables are outside the rider/bike interface(unless altered, but then variances as a result are measurable). Certainly has tempted me to go back to varsity and do an Msc in the sports physiology of cycling.

 

 

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Any reasonable research in power studies should calibrate the power meter.  I mean actual calibration, not Garmin "calibration" (which is zero-offset only, and doesn't include the slope.)

 

You should also understand the power measurement method used to predict the impact of temperature or humidity changes.

 

Since this trainer rubs against your tire, you should confirm tyre pressure and tension.  This will make a huge difference.

 

You should also move your saddle back to confirm the massive change.

 

And you should check the data gathered for any gaps and accidental zeroes due to data dropouts.

 

 

edit: my bet is on tyre tension.

 

 

 

Physiologically it's unlikely to see such a large change in FTP in a short timeframe, unless there's something seriously wrong like a blood flow constriction.

[geoffois]

i have trouble putting the same power out on a indoor trainer as i do on the road.

just putting it out there...

I would assume the incentive to push harder is different between the two as well as the ability to "rest" during freewheeling on the road will affect peak power during the ride. I find I push myself harder on the IDT as I suspect mentally I know if I burn out, I'm still in the safety of my home. Again, this is perceived effort as I don't have a power meter on the bike when road riding.

 

 

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[Furbz]

I would assume the incentive to push harder is different between the two as well as the ability to "rest" during freewheeling on the road will affect peak power during the ride. I find I push myself harder on the IDT as I suspect mentally I know if I burn out, I'm still in the safety of my home. Again, this is perceived effort as I don't have a power meter on the bike when road riding.

 

 

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resting a little yes.

but a FTP test involves a hard constant test regardless of where it is done.

for some reason i cannot even get close to my Road recorded FTP when on my trainer.

 

nb i am using pedal based recording

[Patchelicious]

Lots and lots of variable can influence a power test.

 

For you are serious about it, I would suggest you go see somebody who can help get you an accurate number to work with.

 

Doing "Z5" intervals on a FT setting of 170W, when your real number is 270W will just be a waste of your time