Intensity factor

A light bike doesn't replace good fitness.

Moderator: Moderator Team

TobinHatesYou
Posts: 6627
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

TheRich wrote:
Sun Aug 16, 2020 10:49 pm

Uh no. FTP typically has little to do with your hour power...which would be determined by your average, not normalized, power. The vast majority of people lack the endurance to do an hour of FTP, and if they used their hour of power number, it would be too easy for almost all FTP-based workouts. I'd make a WAG that if you can do an hour at FTP, either your FTP is too low or you've gone overboard and become too much of a diesel.

FTP and NP are just numbers, don't try to find the deeper truth because there isn't one.

Disagree. 60min efforts aren't endurance efforts by any means and you won't run into problems such as glycogen depletion in that time. Coggan's power charts are largely accurate for the general population. Most people who don't come close to their 0.95*20min power or 0.75*(ramp) numbers are failing mentally rather than physically.

by Weenie


TheRich
Posts: 762
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

TobinHatesYou wrote:
Mon Aug 17, 2020 2:38 am
TheRich wrote:
Sun Aug 16, 2020 10:49 pm

Uh no. FTP typically has little to do with your hour power...which would be determined by your average, not normalized, power. The vast majority of people lack the endurance to do an hour of FTP, and if they used their hour of power number, it would be too easy for almost all FTP-based workouts. I'd make a WAG that if you can do an hour at FTP, either your FTP is too low or you've gone overboard and become too much of a diesel.

FTP and NP are just numbers, don't try to find the deeper truth because there isn't one.

Disagree. 60min efforts aren't endurance efforts by any means and you won't run into problems such as glycogen depletion in that time. Coggan's power charts are largely accurate for the general population. Most people who don't come close to their 0.95*20min power or 0.75*(ramp) numbers are failing mentally rather than physically.
Easy for you to say...but either way, most people can't do it.

Cycomanic
Posts: 215
Joined: Tue Feb 04, 2020 11:10 pm

by Cycomanic

TheRich wrote:
Sun Aug 16, 2020 10:49 pm
Cycomanic wrote:
Sun Aug 16, 2020 2:54 pm
I think there's a couple of things to remember:
1. FTP is a convenient measure but it's unclear what (if) it corresponds to anything physiological. Moreover, how did you actually measure FTP hardly anyone ever does 60min TT efforts and everything else is just a way to estimate it.
2. Also if you actually do 60min TT efforts, unless you're very experienced pacing will have a big impact on your numbers.
3. There are efforts that allow you to exceed 1.0 IF in 60min, the so-called NP busters
4. Considering the mentioned uncertainties in FTP measurements maybe your NP value is for thos 60min efforts is actually a better estimate of your FTP.

Coming back to the OP, NP busters are hard you really need to make an focused effort. So if your 0.97 IF 90min ride was "quite hard" it's much more likely that your FTP is too low, than you being a strong physiological outlier.
Uh no. FTP typically has little to do with your hour power...which would be determined by your average, not normalized, power. The vast majority of people lack the endurance to do an hour of FTP, and if they used their hour of power number, it would be too easy for almost all FTP-based workouts. I'd make a WAG that if you can do an hour at FTP, either your FTP is too low or you've gone overboard and become too much of a diesel.

FTP and NP are just numbers, don't try to find the deeper truth because there isn't one.
FTP pretty much by definition is the the power you can sustain for one hour. To quote from the 2nd edition of TRWPM (co-authored by A. Coggan who coined FTP):
"FTP is the highest power that a rider can maintain in a quasi-steady state for approximately one hour without fatiguing". So saying FTP has nothing to do with hour power is weird.
Regarding relationship between FTP and NP the book gives 5 methods how to determine FTP.
  • 1. From power frequency distribution charts
    2. Routine steady state power (such as the often advocated 20min test, although you should actually do the appropriate warm up protocol)
    3. NP: "Perhaps an even more precise way of determining your threshold power, yet one that still does not require formal testing, is to use power-meter software to examine your NP during hard mass-start races of approximately one hour"
    4. One-hour time-trail
    5. Critical Power
Regarding FTP and NP being "just numbers", as I said before it's very unclear if FTP corresponds to something physiological. However, they (similar to CP) are very convenient for determining your training ranges and getting an accurate estimate is important for determining the intensity you want to train in. Otherwise, you might as well not ride with a power meter at all.

TheRich
Posts: 762
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

Cycomanic wrote:
Mon Aug 17, 2020 8:34 pm
TheRich wrote:
Sun Aug 16, 2020 10:49 pm
Cycomanic wrote:
Sun Aug 16, 2020 2:54 pm
I think there's a couple of things to remember:
1. FTP is a convenient measure but it's unclear what (if) it corresponds to anything physiological. Moreover, how did you actually measure FTP hardly anyone ever does 60min TT efforts and everything else is just a way to estimate it.
2. Also if you actually do 60min TT efforts, unless you're very experienced pacing will have a big impact on your numbers.
3. There are efforts that allow you to exceed 1.0 IF in 60min, the so-called NP busters
4. Considering the mentioned uncertainties in FTP measurements maybe your NP value is for thos 60min efforts is actually a better estimate of your FTP.

Coming back to the OP, NP busters are hard you really need to make an focused effort. So if your 0.97 IF 90min ride was "quite hard" it's much more likely that your FTP is too low, than you being a strong physiological outlier.
Uh no. FTP typically has little to do with your hour power...which would be determined by your average, not normalized, power. The vast majority of people lack the endurance to do an hour of FTP, and if they used their hour of power number, it would be too easy for almost all FTP-based workouts. I'd make a WAG that if you can do an hour at FTP, either your FTP is too low or you've gone overboard and become too much of a diesel.

FTP and NP are just numbers, don't try to find the deeper truth because there isn't one.
FTP pretty much by definition is the the power you can sustain for one hour. To quote from the 2nd edition of TRWPM (co-authored by A. Coggan who coined FTP):
"FTP is the highest power that a rider can maintain in a quasi-steady state for approximately one hour without fatiguing". So saying FTP has nothing to do with hour power is weird.
Regarding relationship between FTP and NP the book gives 5 methods how to determine FTP.
  • 1. From power frequency distribution charts
    2. Routine steady state power (such as the often advocated 20min test, although you should actually do the appropriate warm up protocol)
    3. NP: "Perhaps an even more precise way of determining your threshold power, yet one that still does not require formal testing, is to use power-meter software to examine your NP during hard mass-start races of approximately one hour"
    4. One-hour time-trail
    5. Critical Power
Regarding FTP and NP being "just numbers", as I said before it's very unclear if FTP corresponds to something physiological. However, they (similar to CP) are very convenient for determining your training ranges and getting an accurate estimate is important for determining the intensity you want to train in. Otherwise, you might as well not ride with a power meter at all.
The reality is that FTP, as currently used, is determined from much shorter durations and that number determines the power targets for workouts. Period, that's it. Just because Coggen came up with the term doesn't mean he has absolute authority over it's use. You'd have to get into the fine deails of what he prescribes for workouts to really see how his approach compares to the general consensus, so just picking and choosing data is misleading at best.

I have no idea what my one hour power could be, but I would expect to come up short of 95% my 20-minute test, yet estimates work well for interval work for many people. Hard workouts are very hard, and if I used a slightly lower 1-hour number, they wouldn't be as hard, or as effective. If a workout is supposed to take everything you have (like Seiler's 4x8s), and your everything hits the targets, the underlying number is correct. Once you're out riding, not doing a workout, everything goes out the window anyway...that's why I said "they're just numbers" with "no underlying truth."

Cycomanic
Posts: 215
Joined: Tue Feb 04, 2020 11:10 pm

by Cycomanic

TheRich wrote:
Mon Aug 17, 2020 9:47 pm
Cycomanic wrote:
Mon Aug 17, 2020 8:34 pm
TheRich wrote:
Sun Aug 16, 2020 10:49 pm
Cycomanic wrote:
Sun Aug 16, 2020 2:54 pm
I think there's a couple of things to remember:
1. FTP is a convenient measure but it's unclear what (if) it corresponds to anything physiological. Moreover, how did you actually measure FTP hardly anyone ever does 60min TT efforts and everything else is just a way to estimate it.
2. Also if you actually do 60min TT efforts, unless you're very experienced pacing will have a big impact on your numbers.
3. There are efforts that allow you to exceed 1.0 IF in 60min, the so-called NP busters
4. Considering the mentioned uncertainties in FTP measurements maybe your NP value is for thos 60min efforts is actually a better estimate of your FTP.

Coming back to the OP, NP busters are hard you really need to make an focused effort. So if your 0.97 IF 90min ride was "quite hard" it's much more likely that your FTP is too low, than you being a strong physiological outlier.
Uh no. FTP typically has little to do with your hour power...which would be determined by your average, not normalized, power. The vast majority of people lack the endurance to do an hour of FTP, and if they used their hour of power number, it would be too easy for almost all FTP-based workouts. I'd make a WAG that if you can do an hour at FTP, either your FTP is too low or you've gone overboard and become too much of a diesel.

FTP and NP are just numbers, don't try to find the deeper truth because there isn't one.
FTP pretty much by definition is the the power you can sustain for one hour. To quote from the 2nd edition of TRWPM (co-authored by A. Coggan who coined FTP):
"FTP is the highest power that a rider can maintain in a quasi-steady state for approximately one hour without fatiguing". So saying FTP has nothing to do with hour power is weird.
Regarding relationship between FTP and NP the book gives 5 methods how to determine FTP.
  • 1. From power frequency distribution charts
    2. Routine steady state power (such as the often advocated 20min test, although you should actually do the appropriate warm up protocol)
    3. NP: "Perhaps an even more precise way of determining your threshold power, yet one that still does not require formal testing, is to use power-meter software to examine your NP during hard mass-start races of approximately one hour"
    4. One-hour time-trail
    5. Critical Power
Regarding FTP and NP being "just numbers", as I said before it's very unclear if FTP corresponds to something physiological. However, they (similar to CP) are very convenient for determining your training ranges and getting an accurate estimate is important for determining the intensity you want to train in. Otherwise, you might as well not ride with a power meter at all.
The reality is that FTP, as currently used, is determined from much shorter durations and that number determines the power targets for workouts. Period, that's it. Just because Coggen came up with the term doesn't mean he has absolute authority over it's use. You'd have to get into the fine deails of what he prescribes for workouts to really see how his approach compares to the general consensus, so just picking and choosing data is misleading at best.

I have no idea what my one hour power could be, but I would expect to come up short of 95% my 20-minute test, yet estimates work well for interval work for many people. Hard workouts are very hard, and if I used a slightly lower 1-hour number, they wouldn't be as hard, or as effective. If a workout is supposed to take everything you have (like Seiler's 4x8s), and your everything hits the targets, the underlying number is correct. Once you're out riding, not doing a workout, everything goes out the window anyway...that's why I said "they're just numbers" with "no underlying truth."
I think we largely agree (just the typical internet thing argueing over the details :) ). I find Golden Cheetah's CP estimates from riding/racing as well as Xert (which does an amazing job of estimating from limited data) much more useful than doing tests (who has the mental energy to regularly do 1h TT tests?!).

That said, I would say that doing single 20min tests (like I used to do) without the 5 min (IIRC) all-out effort before, typically gives you an overestimate of your FTP.

TheRich
Posts: 762
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

People definitely do cheat by not doing the 5 minutes full gas. That's my favorite part of the testing protocal.

Everything is individual, so different estimates work for some people and not for others. The ratio between my "VO2max"/5-minute power and FTP is a little off, so pretty much every software estimate is more theoretical than practical. Strava, GC, Xert...looks nice, very flattering, but it's not happening in the real world. I'm sure some people have the opposite problem.

They're all just numbers, be aware of them if you want, but don't let them dictate your cycling life. The phrase "not all TSS is created equal" applies to most power metrics.

RyanH
Moderator
Posts: 2834
Joined: Tue Jan 17, 2012 4:01 pm
Location: Los Angeles, CA
Contact:

by RyanH

It's helpful to understand the role of anaerobic working capacity (AWC) and how it affects estimates of FTP. People with high anaerobic working capacity, a 20 min effort will over estimate their ftp while diesel engine types (triathletes in particular) it may actually underestimate their ftp.

Anaerobic working capacity is like KERS in formula one in a sense. It allows you to work above ftp for a period of time and the 95% rule is basically saying that 5% of your power (watt/seconds) during the 20 minute effort was from anaerobic.

@TobinHatesYou from my experience in zwift races, my normalized and avg power are relatively close. If you're seeing IF above 1.0 in zwift races then more than likely your ftp is set too low. Once I begin seeing I'm consistently hitting over 0.95 IF for zwift races, I know I need to retest my FTP and sure enough, it needs to be increased.
Strava
Not for the sensitive types. My Instagram reviews
The Ex's: I've lost track...

TheRich
Posts: 762
Joined: Tue Jan 01, 2019 1:36 am

by TheRich

What determines the accuracy of your FTP?

RyanH
Moderator
Posts: 2834
Joined: Tue Jan 17, 2012 4:01 pm
Location: Los Angeles, CA
Contact:

by RyanH

Whether or not you're able to train off of it.
Strava
Not for the sensitive types. My Instagram reviews
The Ex's: I've lost track...

TobinHatesYou
Posts: 6627
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

RyanH wrote:
Tue Aug 18, 2020 10:06 pm

@TobinHatesYou from my experience in zwift races, my normalized and avg power are relatively close. If you're seeing IF above 1.0 in zwift races then more than likely your ftp is set too low. Once I begin seeing I'm consistently hitting over 0.95 IF for zwift races, I know I need to retest my FTP and sure enough, it needs to be increased.

Only on courses like Innsbruckring do I blast past 1.00 for a full 60min On the courses we’ve raced together, they’ve been close to 1.00, but significantly shorter than 60min.

User avatar
DOUG
Posts: 340
Joined: Thu Mar 31, 2016 9:54 pm

by DOUG

RyanH wrote:
Wed Aug 19, 2020 12:57 am
Whether or not you're able to train off of it.
This. Ive been working with a coach the past couple of seasons and we dont do any testing anymore. Zones are set based on whether or not Im actually able to train effectively in those zones for any given workout. Tracking HR zones and making sure your physiological response is consitent with the prescribed power ranges is important as well.

Once you have enough experience training with power, HR and perceived exertion, every workout and even every interval becomes somewhat of an internalised feedback loop. You will know if you're digging too deep to complete the workout and on the flip side its obvious if its too easy. Once I feel like its becoming too easy to complete each session then we discuss bumping my FTP and seeing how that plays out. If Ive been sick or have had a week off the bike or something then we consider dropping back down if i can't complete my workouts, it doesnt normally take long to come back up to my previous level though. I find SST work gives the best indicator for this because its suppsoed to be feel pretty hard but not so hard you're left wondering if you can do the next interval.

Post Reply