I 100% agree. For me, I think that standardizing a method of testing for this, beyond a simple FTP power test, would allow at least some way for a lot of us to track progress or compare against others, in a similar way we all use your chart to compare peak power numbers. I see less value for pros that already are recovery limited, not time limited, as they are doing all they can to build fatigue resistance as it is.
What really got me thinking about this years ago was a buddy that had similar FTP w/kg, and we were within 15 pounds of each other, same height, etc. His FTP at 5 hours was significantly higher than mine though, and he had a whole box of matches to burn, not just a small match book. I just knew he had more endurance and won more, but there wasnât really any metric at the time to quantify that. The way to train that is doing the longer rides, but if you donât have time for it, will you really change your training? And if you are already doing the long rides, how do you further improve? To your point, Iâm not sure how valuable it will be for both pros or the time crunched athlete.
For me, when speaking of endurance or durability, we are talking about the difference in the power curve from rider to rider on the right side of the graph.
I was just imaging that mitochondria have a duty cycle, and that increasing the count extends that duty cycle by reducing load. Then, I was thinking, maybe very high outputs pressure the mitochondria leading to damage, and that ultimately the ârate limitâ is about preserving mitochondrial function.
Then I did a quick search, AMPK came up, repairing mechanisms, etc. And so the appeared. I canât vanish into it today.
But it did make me think, you know if you have more then the load is lower, so higher ftp = durability. et voila.
edit but now Iâm thinking itâs the fractional percentage of your ftp potential that matters, not your raw ftp. This is maybe where volume matters. Where you are on the diminishing returns arc⌠Maybe thatâs the coffee talking.
(Keep in mind that beyond ~1 h, few of the approximately 200 athletes shown would have gone as hard as they could for the duration. Thus, at least some of the residual variability between individuals is not physiological in nature.)
More specifically, keep in mind that every ~1% difference in power corresponds to a ~10% difference in the duration.
IOW, could he beat up on you and others in longer races simply because his muscular metabolic fitness was greater, but the difference was small enough that it was only really obvious under those circumstances, but not readily detectable in shorter events, even though it was really there?
That actually looks like quite a lot of variation, the choice of axis scales just makes it less obvious out towards 1+ hours.
Like it eyeballs out to 20-50% variation in value power among whatever sample size this was at that time range, which is quite large.
Do you have the standard deviation for that data? Or maybe even r^2 between FTP and various >1 hour power points? Or something that quantifies the spread of the sample values rather than just relying on subjective âeyeballingâ of the data?
I think this all gels together then. That suggests that FTP is the dominant predictor of endurance performance (even for very long events), which I think people agree with. But that it doesnât perfectly predict it, meaning there is room for other independent variables to explain the remaining unexplained variation in performance.
Hereâs the correlation between mFTP and power as a function of duration. The wonkiness at the far right is again due to more and more drop-outs. Out to not quite 6 h, the R is >0.90.
That I donât know, Iâm sure youâre correct. Obviously there was something significantly different about our physiology that was not easily detectable by our fresh power numbers.
Also a sincere thank you for engaging with us (and me) by the way. I bought your Training and Racing with a Power Meter book in 2008, along with WKO and a powertap. I attribute the majority of my early racing success to your book and training principals.
That graph looks to me as if differences in FTP are irrelevant for durations of over 300s (approximately). Surely there is some sort of detail that is getting lost.
Would you disagree with this explanation of fatigue ?
Fatigue at the cellular level would be explained by leakage of electrons (or other inefficiency) at any step in the electron transport chain?
I would expect huge differences, in TTE and RPE, for people riding sweetspots based on their endurance/durability, otherwise people would just start their SST progression at 95% for 1h+.
I think the other thread thatâs talking about this âdurabilityâ concept contains references/reasoning that would argue that mismeasurement or lack of data isnât the only cause of this though.
Like how at a world-level, performance is better predicted by variation in ability to consistently perform repeated intense efforts, rather than aerobic capacity alone. And that there was a large amount of variation in this ability between athletes. Which also suggests that down-stream PDC isnât perfectly predicted by FTP alone (at least at this level).
My take away from reading on all of this, everyoneâs comments here, and reflecting on it all is that âdurabilityâ or whatever youâre going to call it is likely real, but probably only a minor or trivial factor for most riders unless you are pro-level (or perhaps focus on ultra-endurance events). Recreational athletes probably being best served by focusing on improving FTP instead.
That also incorporates personal experience of me having a lower FTP and much worse 40k TT performance than a few friends⌠but kicking their asses on 4-8h rides.
You are apparently misreading the graph. The correlation between (model-derived) FTP and power is >0.9 for all durations from 2.5 min out to not quite 6 h.
ETA: That might be my fault. The Y axis of the last graph I posted is the correlation coefficient, not the CV as indicated (forgot to update it from the prior chart).
Youâre missing the point. Just because you canât detect differences in ability between individuals at shorter durations doesnât mean that other factors are necessarily important at longer durations.
As for the studies you mention, #sportsscienceatitsfinest
appeared. I canât vanish into it today.
