During the workout, the lowest W' value was -8,9 kJ, the question is: should I set my W' value to 13,3+8,9=22,2 kJ ?
Thanks in advance
Andrea
Edit: I just fiddled with the numbers a little bit and I get them more "logical" when I set the critical power as 0,95 * 20min Peak Power and adjust the W' so I get to zero at the end of my FTP test. I think I'll stick to that method from now on.Could it be that the extended model for the CP chart should only be used once you have enough data over the whole power range? As said in previous post I didn't do any short Z6+ sprints last month. Maybe that's why W' was modelled too high.
Rob Manning I'm not seeing how to add this? I've got the Feb 13 development release, is that not the 3.2 dev release? On Friday, March 20, 2015 at 8:25:07 AM UTC-4, Patrick wrote: ...more |
Mark,I agree that the Ward Smith model would be a nice addition since it plays very nicely with the VC (W' plot). Just make sure the appropriate version gets in unlike what was used in the WKO4 miniseries. The correct version:P(t) = W'/t * ( 1- exp(-t/( W'/(wPmax) ) ) ) + CPnote that wPmax = Pmax - CP
But in GC you need an FTP value to get your TSS / PMC / Time-in-zones etc to "work".Whereas if you get CP/W' wrong the only consequence is W'Bal plot is off.IE Until GC separates CP & FTP it seems more practical to use FTP as 'CP' and 'fudge' the W'Pete
But in GC you need an FTP value to get your TSS / PMC / Time-in-zones etc to "work".Whereas if you get CP/W' wrong the only consequence is W'Bal plot is off.IE Until GC separates CP & FTP it seems more practical to use FTP as 'CP' and 'fudge' the W'Pete
Nathan, thank you for your testing guidelines.There's one thing you write, that I have a hard time understanding, can you help:> As a doublecheck, go and do a 20-30 min TT. If you are relatively out of shape, choose closer to 20min. If you're in good shape then choose closer to 30min. This value should coincide closely with your CP estimate.Why is that? If I ride all-out, shouldn't my average power then be above CP, since P(t) = CP + W'/t?/Rolf
Nathan, just to elaborate a little:
My intuition is that there has been a shift in the understanding of CP from back when the classical 2-parameter model was formulated, so that the CP you are working with is a somewhat different CP-definition from the "classical one" and hence that the test procedure you describe captures a different physiological state than the one "classically" captured with the 3 and 20 minute tests. That would for me explain why CP can be above FTP, which really is incompatible with P(t) = CP + W'/t for any W' > 0... at least within the timespan where the model is valid.
And more about definitions - because, if the CP you are working with ("modern CP") is sustainable for a significantly shorter timespan than the quasi-steady-state that Coggan is referring to can be sustained, if it perhaps is only sustainable for 15 minutes, then the FTP-model and the "current CP-model" probably don't converge... because, a two-parameter model based on the "modern CP" is not able to predict performance for longer timespans than 15 minutes ... because, after 15 minutes the VO2 Slow component effect kicks in and lowers one's "effective CP" ... so even though P(t) = CP + W' / t still is true, a continually decreasing CP means that the two-parameter model overestimates P(t).
Is this completely off the wall? And if not, then how do I predict MMP60 from CP and W'?
:) Rolf
Hi Nathan> If you ride as hard as you can for about 15min, and then model the results using P(t) = CP + W'/t, then the asymptote value here (ie: CP) will be pretty close to what you can actually do for about 25-30min.,> Make sense?Yes and no. Empirically / by experience, you may very well be right, but mathematically no, given a) P(t) = CP + W'/t and b) valid estimates of CP and W'.But, and this is where my limited knowledge of physiology kicks in, perhaps the discrepancy boils down to differences between the assumption af what CP represents in the classical two-parameter-model and what seems to be a more current / advanced physiological understanding of CP that you are working with?In any case, it's something I've been trying to reconcile / unite conceptually for a while; FTP, MMP60 and the classical two-parameter model.In my naive world, I would like the following to be true: FTP ~= MMP60 (or MMP55) ~= CP + W' / 60 (or 55) minutes :)Does that make sense?/Rolf
Nathan, just to elaborate a little:
My intuition is that there has been a shift in the understanding of CP from back when the classical 2-parameter model was formulated, so that the CP you are working with is a somewhat different CP-definition from the "classical one" and hence that the test procedure you describe captures a different physiological state than the one "classically" captured with the 3 and 20 minute tests. That would for me explain why CP can be above FTP, which really is incompatible with P(t) = CP + W'/t for any W' > 0... at least within the timespan where the model is valid.
And more about definitions - because, if the CP you are working with ("modern CP") is sustainable for a significantly shorter timespan than the quasi-steady-state that Coggan is referring to can be sustained, if it perhaps is only sustainable for 15 minutes, then the FTP-model and the "current CP-model" probably don't converge... because, a two-parameter model based on the "modern CP" is not able to predict performance for longer timespans than 15 minutes ... because, after 15 minutes the VO2 Slow component effect kicks in and lowers one's "effective CP" ... so even though P(t) = CP + W' / t still is true, a continually decreasing CP means that the two-parameter model overestimates P(t).
Is this completely off the wall? And if not, then how do I predict MMP60 from CP and W'?
:) Rolf
I compute TSS based on CP (in that I set my "FTP" to be my CP).This shifts my TSS downward for a given effort since CP > FTP, but as Nathan points out -- TSS is a relative measure.A bit more on my switch from FTP to CP .... there is published literature that estimates CP based on a power ramp test.
Thank you, Nathan, this is really interesting.Just to be clear:> The CP model is no good at predicting sustained performance for any duration at, or below CP, because by definition, CP is the asymptote.So, a) if I'm somewhat average and able to sustain CP for 25 minutes, then the two-parameter model should be OK at estimating my "power potential" for durations up to those 25 minutes (CP plus ekstra anaerobic work "fueled" by W'), but for durations longer than the 25 minutes the model will gradually overestimate more and more because of central fatigue, VO2sc and other effects not modelled?
And b), as for the relationship between CP and FTP, there really isn't any, because they are based on two different ways of evaluating performance potential. FTP can be said, and this is meant kindly, to be a performance-based gold standard (we have hour records for a reason, there is a raw appeal in going all-out for an hour, cracking 40 k's for an hour for the first time on your road bike just feels really good :), whereas CP is a measure of the power one is producing in a physiologically well-defined maximal-quasi-steady-state. Both are true, both are usefull, but there's no immediate connection.:) Rolf
Determination of Critical Power Using a 3-min All-out Cycling Test
ANNI VANHATALO1, JONATHAN H. DOUST2, and MARK BURNLEY1
1Department of Sport and Exercise Science, University of Wales, Aberystwyth, UNITED KINGDOM; and 2Chelsea School Research Centre, University of Brighton, Eastbourne, UNITED KINGDOM
ABSTRACT
VANHATALO, A., J. H. DOUST, and M. BURNLEY. Determination of Critical Power Using a 3-min All-out Cycling Test. Med. Sci. Sports Exerc., Vol. 39, No. 3, pp. 548–555, 2007. Purpose: We tested the hypothesis that the power output attained at the end of a 3-min all-out cycling test would be equivalent to critical power. Methods: Ten habitually active subjects performed a ramp test, two 3-min all-out tests against a fixed resistance to establish the end-test power (EP) and the work done above the EP (WEP), and five constant–work rate tests to establish the critical power (CP) and the curvature constant parameter (W¶) using the work–time and 1/time models. Results: The power output in the 3-min trial declined to a steady level within 135 s. The EP was 287 T 55 W, which was not significantly different from, and highly correlated with, CP (287 T 56 W; P = 0.37, r = 0.99). The standard error for the estimation of CP using EP was approximately 6 W, and in 8 of 10 cases, EP agreed with CP to within 5 W. Similarly, the WEP derived from the 3-min test (15.0 T 4.7 kJ) was not significantly different from, and correlated with, W¶ (16.0 T 3.8 kJ; P = 0.35; r = 0.84). Conclusions: During a 3-min all-out cycling test, power output declined to a stable value in approximately the last 45 s, and this power output was not significantly different from the independently measured critical power. Key Words: EXERCISE INTENSITY DOMAINS, EXERCISE TESTING, ANAEROBIC CAPACITY, POWER–DURATION RELATIONSHIP, PEAK V ̇ O2