Normalised power

peterpen said:

Tagging onto the end of this, what would people say about the following #'s?
Race:
Duration: 2:02:50
Work: 1805 kJ
TSS: 200.1 (intensity factor 0.989)
Norm Power: 287
VI: 1.17
Distance: 80.31 km
Min Max Avg
Power: 0 955 245

Peak 60min (268 watts):
Duration: 1:00:01
Work: 964 kJ
TSS: 113.5 (intensity factor 1.065)
Norm Power: 309
VI: 1.15
Distance: 40.227 km
Min Max Avg
Power: 34 955 268 watts

This was a flat RR in which I was very active (attacking, working for our sprinter) so there were some 2-4m sections w/ avg watts 100 over FTP, which might pump up the VI a bit. TSB was -7TSS, it was the end of a solid week of build, and I did two crits the day before.

When combined with recent intervals, these data make me feel I should adjust FTP up from 290w - any guesses as to where it will land?

Sounds like a real increase PP 🙂. Those VI's aren't that high at all.
I'd suggest halfway between 290W and 309W or 300W. Training and re-testing should confirm that in due time.

acoggan said:

I think the best answer to that question is "rarely" (but not "never"😉.

Note: the average VI for the four files in which AP was the better estimate of functional threshold power was 1.21, which is actually less than the average for all of the "NP buster" files I've collected (which is 1.38). IOW, the degree of variability doesn't seem to be a distinguishing factor. Similarly, I have been unable to identify any common characteristic of these files - or for the 27 "NP busters" that I have collected - that would explain what makes them different.

Hi,

I've have the same question. I did 436 NP watts this weekend and 393 AP watts for 20 minutes. The test was on a hilly route. Which one is the best measurement for my FTP ? (only 95% I know)

clausfod said:

Hi,

I've have the same question. I did 436 NP watts this weekend and 393 AP watts for 20 minutes. The test was on a hilly route. Which one is the best measurement for my FTP ? (only 95% I know)

Lots of power there! I'll ask the std. question: just how HARD was it? 🙂

In any case, simply taking 95% of 20MP isn't recommended. I would suggest doing a 5MP test and plugging the 5MP and 20MP results into a CP-Monod spreadsheet. Or doing a full-on 40k test.

edit: can I ask what PM you're using?

rmur17 said:

Lots of power there! I'll ask the std. question: just how HARD was it? 🙂

In any case, simply taking 95% of 20MP isn't recommended. I would suggest doing a 5MP test and plugging the 5MP and 20MP results into a CP-Monod spreadsheet. Or doing a full-on 40k test.

edit: can I ask what PM you're using?

Hi,

I was using my SRM Ama. The 20 minutes was hard - but I think I could have done better. My heart rate was 164 Avg (max is 192) My rest heart rate is 38 so the my avg. heart rate was only approx 82%.

Can I ask - what is a CP-Monod spreadsheet ?

clausfod said:

Hi,

I was using my SRM Ama. The 20 minutes was hard - but I think I could have done better. My heart rate was 164 Avg (max is 192) My rest heart rate is 38 so the my avg. heart rate was only approx 82%.

Can I ask - what is a CP-Monod spreadsheet ?

okay from your PE it sounds as though you're due for another test or two anyway 🙂

velo-fit.comcritical power.pdfOpen ↗

I'm not sure the .xls file can be downloaded directly there but it's really very, very easy. All you need is two 'maximal' tests (I suggest 5 and 20-min) and it will predict your CP from the slope of the Work-Time line. CP and FTP are basically equal.

rmur17 said:

Sounds like a real increase PP 🙂. Those VI's aren't that high at all.
I'd suggest halfway between 290W and 309W or 300W. Training and re-testing should confirm that in due time.

Yep, that's what I'm thinking as well. Next week is a rest week, so I'll probably do a few all-out efforts, through 'em in Monod, and confirm things.

The NP concept is pretty nifty. 😎

to psucycling (email but I can't see your post here???):

Drop the 60" wattage - way too low to use in Monod. When I plug in your 5MP and 20MP, I get a CP of 325W or within 10W of your estimate. It's not too bad 🙂

edit: I noted the AWC estimate is only 7500 kJ which is very low. I'd 'predict' your 5MP test is a little low. Let's say it's 20W low - that would drop CP to 320W.

rmur17 said:

to psucycling (email but I can't see your post here???):

Drop the 60" wattage - way too low to use in Monod. When I plug in your 5MP and 20MP, I get a CP of 325W or within 10W of your estimate. It's not too bad 🙂

edit: I noted the AWC estimate is only 7500 kJ which is very low. I'd 'predict' your 5MP test is a little low. Let's say it's 20W low - that would drop CP to 320W.

yeah i figured out what i did wrong so i deleted the post. I'm getting an estimate of 322, which is close to my guess of 315-320 or 4.75w/kg!!

yes my 60" is low, that was a number taken from last season as a cat3.

rmur17 said:

Sounds like a real increase PP 🙂. Those VI's aren't that high at all.
I'd suggest halfway between 290W and 309W or 300W. Training and re-testing should confirm that in due time.

BTW, if I pull 2, 5, and 10m max avg powers from that same file and plug them into Monod, guess what it spits out as 60m power? Yep, 300 on the nose.

peterpen said:

BTW, if I pull 2, 5, and 10m max avg powers from that same file and plug them into Monod, guess what it spits out as 60m power? Yep, 300 on the nose.

I shall buy some lottery tickets tomorrow 🙂

peterpen said:

BTW, if I pull 2, 5, and 10m max avg powers from that same file and plug them into Monod, guess what it spits out as 60m power? Yep, 300 on the nose.

You're probably already aware of this, but picking up MMP data points from the same ride file has tendencies to underestimate your AWC and to overestimate your FTP unless you do a separate all-out effort for each duration with sufficient rest periods in between.

Ken

sugaken said:

You're probably already aware of this, but picking up MMP data points from the same ride file has tendencies to underestimate your AWC and to overestimate your FTP unless you do a separate all-out effort for each duration with sufficient rest periods in between.

Ken

Why is that? I can see the underestimated AWC more easily than the over-estimated FTP.

FWIW, I wager the 300w is spot on for my FTP *on the flats.* Fairly sure I could do 5-10w more on a steady climb. Now if I can just get rid of that damn last kilo and get down to 64. (and remember to chill-out for the first 2/3 of the damn race. :o )

peterpen said:

Why is that? I can see the underestimated AWC more easily than the over-estimated FTP.

Because it's likely that your MMP for shorter duration during a long ride is lower than it would be when you did a separate bout for the same duration because you either have already used up some of your AWC, or may unconciously reserve your AWC for later use.

Take a look at this graph. This is essentially what Nomod.xls does. You plot your total work against time, and the Y intercept (at t=0) is your AWC, and the slope of the line is your CP (which, according to Dr. Coggan, you should use as your FTP estimate).
[img]www5e.biglobe.ne.jpCPgraph.pngOpen ↗[/img]
In this graph, if you lower the total work for the shorter duration, you see you'll get steeper slope and lower intercept, meaning higher CP and lower AWC, respectively. If you don't do isolated efforts, your AWC will not be fully utilized during the effort so your total work for the duration will be lower, but AWC loss will have higher impact on shorter efforts than on longer efforts, so your shorter effort's total work will be lower relative to total work of your longer efforts, leading to underestimation of your AWC and overestimation of your CP.

Of course you can tip the balance the other way if you do the shorter effort first then do the longer later so that the graph will look flatter.

I don't know if I'm doing a good job explaining this but I sure hope it clarifies the issue...

Ken

Thanks - that makes it quite clear.

In my example, I think the 'danger' lies in pulling values from a race file. While my motivation is never higher than in a race, I'll rarely go 'all-out, gonna pass-out and fall off the bike' for any duration longer than a few minutes, until the finale. And by that time, I'm probably a wee bit tired. :p

On the other hand, perhaps the #'s that result from a race might be a bit more realistic than ones derived from fully-rested, isolated training efforts. After all, I'm training to race, not training to train. In either case, I suspect the differences may end up falling into the margin of error for PM's as well as the day-to-day fluctuations of FTP.

sugaken said:

...I don't know if I'm doing a good job explaining this but I sure hope it clarifies the issue...

Beautifully illustrated point Ken!

peterpen said:

On the other hand, perhaps the #'s that result from a race might be a bit more realistic than ones derived from fully-rested, isolated training efforts. After all, I'm training to race, not training to train. In either case, I suspect the differences may end up falling into the margin of error for PM's as well as the day-to-day fluctuations of FTP.

Realistic in what way? Training routines typically involve a fair amount of reserve from the absolute physical limit (ie, work at 90-95% of max power, or work at 100% of max 1hr power, but only for 20min, etc.). If additional conservatism is built into the physical limit by taking numbers from a race (where a certain tactical reserve is usually held until the end), then it just makes hitting the desired training intensities more complicated.

Personally, I prefer to know what my physical limit is. That way, when I exceed that value it can be attributed to physical improvement rather than a motivation to dig deeper.