AWC and its effect on Power f(duration)



rmur17

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Oct 5, 2004
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with some discussion ongoing on the FTP thread, i thought I'd post some data here. Since 2002 I've tracked my own Power-duration curve and since 2003 have been checking how that relates to CP-AWC using the Monod method.

To keep things reliable I've been using two simple test durations: roughly 5-min and roughly 20-min. As I often do hard w/o's or testing on the ergometer, I don't fix the duration on those - basically those w/o or test would be to failure at XX power for duration T. Practically speaking it means my ~ 5MP points are taken in the 4-7min range and my ~20MP points in the 18-25 min range.

Anyhow enough dribble about that. Over the past 4-5 yrs, I found that my AWC as measured by the above method varies from a baseline of around 20-25kJ (avg. 22 kJ) up to 28-32kJ (avg. 30kJ) when I've been doing plenty of L5 work and perhaps some L6 (either structured or not). Roughly speaking, I've found that training the shorter e/o the curve adds some 7500 J to my AWC.

It's pretty simple math to see how much AP over duration that additional AWC represents: (7500/duration_in_seconds, rounded to nearest W) in absolute terms

60-min : 2W
30-min: 4W
20-min: 6W
10-min: 12W
05-min: 25W

Now I figure given my history and likely phys. makeup that my delta AWC is probably low compared to the norm or certainly not high.

I'd encourage others to do the same sort of check and compare the delta_Watts as a percentage of FTP.
 
Interesting, if I just use my 5m and ~20m MMP, my AWC comes out to ~37kJ. If I add a third value for my 1m MMP, it reigns it in to 29kJ. Which is a closer estimate?

If it makes any difference, I'm an 80.9 kg NP-Buster type rider. Profile goes down steadily from 5s to FTP, with 7 rows of difference between the two.
 
waterrockets said:
Interesting, if I just use my 5m and ~20m MMP, my AWC comes out to ~37kJ. If I add a third value for my 1m MMP, it reigns it in to 29kJ. Which is a closer estimate?

Neither, really - among other things, the Monod concept essentially assumes that there is a perfectly linear relationship between work and duration. This isn't quite correct, however, which makes the magnitude of AWC (and critical power) somewhat dependent upon test duration. The safe bet, then, is to always utilize tests of similar duration when calculating AWC and critical power.
 
acoggan said:
Neither, really - among other things, the Monod concept essentially assumes that there is a perfectly linear relationship between work and duration. This isn't quite correct, however, which makes the magnitude of AWC (and critical power) somewhat dependent upon test duration. The safe bet, then, is to always utilize tests of similar duration when calculating AWC and critical power.
Makes sense. I'm always going for the 5 and 20, but I haven't standardized on the third test. Sometimes 7m, sometimes 3m...
 
waterrockets said:
Makes sense. I'm always going for the 5 and 20, but I haven't standardized on the third test. Sometimes 7m, sometimes 3m...
I'd just drop the 3rd test (as would RChung I'm sure if he's reading :p )
 
acoggan said:
Neither, really - among other things, the Monod concept essentially assumes that there is a perfectly linear relationship between work and duration. This isn't quite correct, however, which makes the magnitude of AWC (and critical power) somewhat dependent upon test duration. The safe bet, then, is to always utilize tests of similar duration when calculating AWC and critical power.
hi Andy,
I agree with those points for sure. Doing 5/20 gives one a nice reference power for 5MMP in the power-profiling charts and 20MMP --well some folks like to use/reference that and it certainly is a super reference power for 10-mile TTs!!

May I ask a question about the different types of training that improve AWC? I guess the standard prescription would be L6 training with 8-10 repeats of 1-min intervals > 150% of FTP with longish rest intervals. And that'd be taken over a 4-8 wk period.

How much do you figure std L5 training tends to improve AWC in comparison to std. L6? I mean 4-6 reps of (6-4 min @1.10-1.20 FTP) with 0.5-1.0 rest/work ratios?

Dropping the power even further, what you say about a workout consisting of:
  1. Hard UL4-LL5 power interval 18-20min to failure [5min rec]
  2. Same power ~ 10-15 min to failure [5min rec]
  3. Same power ~ 8-10 min to failure
In all cases the power level would be about 1.05-1.10 FTP with the three intervals taken to absolute failure and the duration dropping due to progressive fatigue.

Basically I'm wondering if one can 'kill two birds with one stone' with that approach. Maybe even three birds if you know what I mean :) . Or would they merely be wounded ????
 
rmur17 said:
May I ask a question about the different types of training that improve AWC? I guess the standard prescription would be L6 training with 8-10 repeats of 1-min intervals > 150% of FTP with longish rest intervals. And that'd be taken over a 4-8 wk period.

How much do you figure std L5 training tends to improve AWC in comparison to std. L6? I mean 4-6 reps of (6-4 min @1.10-1.20 FTP) with 0.5-1.0 rest/work ratios?

I think the easiest way to answer that question is to consider what anaerobic work capacity as determined using the critical power approach really represents, which is simply resistance to muscular fatigue during very high intensity (i.e., supra-critical power) exercise. From that perspective, then, I'd expect intervals such as you describe to have some impact on anaerobic work capacity (and in fact this is consistent with my personal experience)...but not as much as level 6 intervals, and perhaps not when the effect of such training is measured another way (e.g., in terms of maximal accumulated O2 deficit, which is a "purer" measure).

rmur17 said:
Dropping the power even further, what you say about a workout consisting of:
  1. Hard UL4-LL5 power interval 18-20min to failure [5min rec]
  2. Same power ~ 10-15 min to failure [5min rec]
  3. Same power ~ 8-10 min to failure
In all cases the power level would be about 1.05-1.10 FTP with the three intervals taken to absolute failure and the duration dropping due to progressive fatigue.

Basically I'm wondering if one can 'kill two birds with one stone' with that approach. Maybe even three birds if you know what I mean :) . Or would they merely be wounded ????

With that workout, I think the birds might escape unscathed. ;)
 
acoggan said:
I think the easiest way to answer that question is to consider what anaerobic work capacity as determined using the critical power approach really represents, which is simply resistance to muscular fatigue during very high intensity (i.e., supra-critical power) exercise. From that perspective, then, I'd expect intervals such as you describe to have some impact on anaerobic work capacity (and in fact this is consistent with my personal experience)...but not as much as level 6 intervals, and perhaps not when the effect of such training is measured another way (e.g., in terms of maximal accumulated O2 deficit, which is a "purer" measure).



With that workout, I think the birds might escape unscathed. ;)
okay thanks for the reply re #1 and #2.

Re #3, surely one of the birds is at least getting winged? :p But I think I hear what you're saying - after such a workout I do feel like I'm in the DMZ :eek: .

So perhaps instead of one weekly w/o like the above, you'd suggest a proper L5 blitzkreig?

Hmmm .. who started the military-speak? :eek:
 
I just do 6x1m intervals as hard as I can once or twice/month. I start off with an all-out sprint, then just keep every pedal stroke as hard as possible. It's really tough, but it seems to have developed my 1m power better than sustained maximal intervals did. I was running about 180% FTP sustained, and had been pretty flat over time. Starting off with that sprint really seemed to trigger the right adaptation.
 
rmur17 said:
hi Andy,
I agree with those points for sure. Doing 5/20 gives one a nice reference power for 5MMP in the power-profiling charts and 20MMP --well some folks like to use/reference that and it certainly is a super reference power for 10-mile TTs!!

May I ask a question about the different types of training that improve AWC? I guess the standard prescription would be L6 training with 8-10 repeats of 1-min intervals > 150% of FTP with longish rest intervals. And that'd be taken over a 4-8 wk period.

How much do you figure std L5 training tends to improve AWC in comparison to std. L6? I mean 4-6 reps of (6-4 min @1.10-1.20 FTP) with 0.5-1.0 rest/work ratios?

Dropping the power even further, what you say about a workout consisting of:
  1. Hard UL4-LL5 power interval 18-20min to failure [5min rec]
  2. Same power ~ 10-15 min to failure [5min rec]
  3. Same power ~ 8-10 min to failure
In all cases the power level would be about 1.05-1.10 FTP with the three intervals taken to absolute failure and the duration dropping due to progressive fatigue.

Basically I'm wondering if one can 'kill two birds with one stone' with that approach. Maybe even three birds if you know what I mean :) . Or would they merely be wounded ????
Rick, it sounds like you want to change bikes halfway through a TT.:p

If you raced track with only that sort of training, you'd be squashed (unless your AWC/NMP was naturally good). You need the short duration high intensity stuff to build the AWC required to perform there. But is that your goal? I doubt it.

You are looking for those last few watts in a 60-min effort. Well even if you gain them by improving your AWC, by what method are you going to deploy it in a TT? You could end up screwing with your pacing strategy.

An emphasis on AWC can come at some cost to your aerobic development time. I don't think there are short cuts. But there's nothing stopping you combining "pure" L5 efforts and "pure" L6 efforts in one session.

I think you know what I mean by "pure" - IOW being specifically focussed on that adaptation but recognising the training continuum and all that, or the "classic" 4-6 min efforts and the "classic" 30-60 sec efforts.