Are CP 1,6,12,30,60etc the Only guidelines & why?

jeff828

I have read several articles about finding your critical power at certain durations and a lot of people have come up with the CP 1,6,12,30,60minutes and was wondering if there is a reason for these specific durations and why. It would seem that 5minutes difference in time, there would be a lot of difference in what Critical power you could hold, for instance there would be a difference between a 5min & 10min and between 10min & 15min and so on. So would you do intervals at 5min,10,15,20,25 etc. since they would all have different wattages you could hold for that duration.

Between CP12 & CP30 there is a big time gap, how about doing a CP20, would that have any benefit? How about the gap between CP30 & CP60, would there be any reason to find out your CP45min and do intervals at that also, since that wattage number should be in the middle.

I do intervals at a CP2min, 4min, 10min, 20min & 30min, all the wattages are different, is there anything wrong with these durations since its not the typical CP 1min, 6, 12, 30 Friel recommends.

What’s the different physiological benefit in doing the recommended CP12min verses my CP10min or doing a his CP 6min verses a CP5min. Basically do the recommended durations have to be exactly that duration or are they somewhat of a guidline. I hope someone can understand what I am trying to ask.

frenchyge

I believe CP is plotted on a logarithmic scale, right? That'd be the reason for not using a linear interval like 5,10,15,20,etc.

The difference between CP6 and CP12 (doubling the time) is about the same as the difference between CP12 and CP30, and CP30 to CP60. The power values at these exponentially increasing durations plot as a straight line on a logarithmic scaled axis.

acoggan

You can understand almost everything about somebody's capabilities by measuring their maximal power at just three durations:

1) for 5 s or less, to quantify their neuromuscular power, and

2) during two efforts of between 1 min (ideally at least 3 min) and perhaps 30 min duration, to determine their critical power and anaerobic work capacity as discussed here:

http://lists.topica.com/lists/watta...l?mid=903428277

Thus, there is really nothing to be gained by measuring power at a host of durations (ala Friel), because at least within the range we're talking about here, power at any one duration can be accurately predicted from power at any two others. (The reason that you need the 3rd point to define neuroumuscular power is because the critical power concept falls apart at durations <1 min.)

Slightly greater insight into this question can be obtained by testing at four durations specifically selected to reflect key physiological traits, i.e., neuromuscular power (as above), anaerobic capacity (related to anaerobic work capacity as defined above), VO2max, and lactate threshold. The ideal durations are somewhat open to debate (since all represent a compromise), but IMO 5 s, 1 min, 5 min, and 60 min (or however you determine your functional threshold power) are best. More information on this approach can be found here:

http://www.cyclingpeakssoftware.com/profile.html

What you gain by adding the fourth measurement is a better understanding of what determines somebody's performance when the effort is only a few minutes in duration. In the critical power concept, an exceptionally high power over such a period of time relative to what can be maintained for longer durations would be interpreted as reflecting a high anaerobic work capacity. In reality, however, such an observation is best interpreted as simply indicating excellent resistance to fatigue during short duration, high intensity exercise, and could also be due to having a high VO2max relative to lactate threshold. Comparing power at 1 min vs. 5 min and 5 min vs. functional threshold power allows you to better differentiate between these possible explanations.

RipVanCommittee

Thanks for explaining what I kinda thought, intuitively. For this reason, I really do think that determining 1 and 5 min Pwr is pretty valueable. I say that since a common prescription for 1 min intervals is 1.75XFTP--which is actually over my max 1 min Pwr! 90 percent of max seems like a better prescription. Your comment also makes me understand why my 1min and 3 minute power are within less than 5% of each other.

joule

Is there any resource available that details what you should expect these ranges to be relative to each other? I realize you cannot compare one person's power value to another's unless there weight's a very similar. More interested in knowing (at the amateur racing level) how I compare so I know what I am weakest in, strongest, etc. For example my 30 min power might be quite good compared to my 3 min power (or the other way around).

frenchyge

The second link in the passage you quoted discusses that.

joule

Many thanks. Exactly what I was looking for. Given the information is accurate, tells me where I need to train the most in the off season.

fergie

I still have a problem with critical power. Anything over 30sec involves pacing oneself for the duration. Some riders are going to be better at it than others. A time trialist is going to have a better ability to pace themselves for a set duration. I also don't expect many road riders who excell in a bunch environment will be motivated to ride a windtrainer or solo TT for 30min.

Hence why I prefer a ramped test.

Hamish Ferguson
Cycling Coach

frenchyge

Can you elaborate on how you use a ramp test to determine the entire power vs. duration curve for a rider?

fergie

From the ramped test one can find power output at aerobic threshold, anaerobic threshold, vO2max and MAP. The only time based test they do is a 30sec wingate although I get sprinters to do a 10sec test.

One can work out power to weight for this to determine where their strengths and weakness's lie and how to plan a programme to make improvements.

Hamish Ferguson
Cycling Coach

frenchyge

Wow! Is all that figured from just the power outputs, or are blood and respiratory measurements done during the test as well?

acoggan

As you would predict based on the underlying theory, individuals don't have to be able to pace themselves well to accurately determine their critical power - in fact, you get the same results whether each exercise bout is performed at a constant power, or starts with an all-out sprint (e.g., as in a pursuit):

http://www.ncbi.nlm.nih.gov/entrez/...5993&query_hl=4

fergie

I measure lactate, HR and VO2 while doing the ramped test.



This study was time to exhaustion. This isn't how we race. As for pursuiting you do want to start fast but only to get to goal pace. It's not really a sprint to max speed.

Hamish Ferguson
Cycling Coach

acoggan

No, but is how critical power is determined in a laboratory setting - not that it really matters, since you get comparable results with fixed duration/fixed distance tests.