Norm Power calculator anywhere?

[nreimche]

I am wondering if there is a website or tool I can calculate Norm power for various wko's? For instance say I want to do a ride of 1.5 hours, but I want to average 230 watts Norm power, and I want to do intervals, not just a steady ride at 230 watts. Within that I ride, if I want to work on muscular endurance like threshold or tempo, and I can do 30 minutes at 260 watts 30 minutes at 200 watts and 30 minutes at 230 watts, but then the norm power would be higher then 230. That wouldn't be bad, but hypothetically I want to be precise, for the point of the question. One more example I did a CTS field test, in which, my average power was about 190 watts, but my Norm power was 240. Again, is there a way w/out sifting through a bunch of files to get an estimate of norm power for rides like VO2 max intervals to something more steady or even more erradic, but predictable? Thanks.

[lorduintah]

You might choose to use the lap marker - this creates a stored time for that interval - the software can then give you an analysis for each "lap"


Tom

[R Mc]

I think he wants to calculate the required power outputs BEFORE the ride.

I've seen the equation for PNorm before--possibly in Coggan and Allan's book.

[lorduintah]

I found a little on this - one takes the time at an interval multiplied by the power - raised to the 4th power. then sums that up over all the individual segments, divide by the total time and take the 4th root to get the NP. You could easily set up an Excel sheet to do this, enter times and power levels and use the optimize or just play with the numbers to get your desired final NP.

from the site listed below:

"Taking our earlier ride data:

10 minutes at 145 watts
20 minutes at 265 watts
30 minutes at 175 watts

Instead of multiplying each power segment by the time for which it was held, we will first raise each power segment to the fourth power, then do the averaging. Finally, we’ll take the fourth root to bring everything back to normal units.

(10x145^4)+(20x265^4)+(30x175^4)

Divide that sum by 60, and take the fourth root…

216 = Normalized Power (“NP”)

If we apply the same algorithm to the constant-effort ride where we just “sat on” 200 watts for the whole 60 minutes, we get NP = 200."


The URL is: http://www.slowtwitch.com/Training/Gene ... a_302.html

Maybe this is what you need.

Your NP from your example is :

x = [(30*260^4) + (30*200^4) + (30*230^4)]/90
NP = x^.25 = 233.8

This is close to your 230 target, but you could fiddle with the time or power of any segment to get exactly 230 overall.

Tom

[nreimche]

Thanks. Tough equation though. I'll have to get used to it over and over if I want to develope a whole set of workout's, which I thought I might do. Too bad I'd have to use Microsoft Excel for the equation, ALSO, becuase I don't know how to use it nor do I have the software (free trial, only, I have- Sounds like Yoda!). Thanks, again for your input everybody.

P.S. I guess I'll just do workouts, and over time I will get an idea of Norm power, not average, for Variably Paced rides. Randomly paced or fartlek rides are the exception of course!

[lorduintah]

You can also get free equivalents of Excel - from SourceForge - NeoOffice - this can run on a PC or a Mac - no need to buy MS Office. Do a google search for NeoOffice and you will find a download. The software runs out of Java. SUN also has an office equivalent software package. For what you want this should not be too tough an assignment. There is also OpenOffice (OpenOffice.org)

The equations only look a little complicated due to the notations I had to use - these are just values raised to the fourth power and then take the fourth root. You could do this on a scientific calculator - but it would be more cumbersome, unless it was a programmable one - a TI-83 or the like.

This could also be something that Travis puts into the software in a future release - enter a set of values in the interval training table - it calculates the NP - then you could adjust the power/times to get your desired NP.

I have some free time - I am UPLOADING THREE FILES - one is for NeoOffice (.ods), another OpenOffice spreadsheet and the other is for Excel (.xls) - either will handle 4 intervals, with a little more work you could expand this for more intervals, or other possible choices - such as automatic optimization of each interval to get the overall NP.

Tom