to zero avg or not?: Triathlon Forum: Slowtwitch Forums

to zero avg or not?

Jun 28, 11 5:17

Post #1 of 7 (1580 views)

that is my question.

i was fiddling with my Garmin 500 the other day, even after my mom told me i'd go blind, and i re-saw the zero avg for power numbers option. so i switched it to a NON zero avg.

here's where my question comes in. my numbers for last night were 50watts higher than normal for the displayed avg watts. (i have lap avg as well as 3sec avg showing, and they were consistent/made sense with each other) My legs felt like that was justifiable, but that's a ~15-20% increase over the same course? (weekly R-B-R-B-R) so i get home with no energy left to spare, hook up the Garmin to WKO+ and had the good times of dealing with an 'unrecognized mass storage device'. Damn you Garmin for your corrosion susceptible plugs! long story shorter, the data is gone (after a successful hook up this morning).

is the 50watt bonus a result of the non zero avg setting? or was i just feeling good last night?

Tim

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Re: to zero avg or not? [twinracer2] [ In reply to ]

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Rocketman

Jun 28, 11 6:05

Post #2 of 7 (1548 views)

Yes, it is a result of not using zeros in the calculation.

You should set it to display zero average.

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Re: to zero avg or not? [Rocketman] [ In reply to ]

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TimAndrus

Jun 28, 11 6:11

Post #3 of 7 (1540 views)

balloon deflated............

Tim

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Re: to zero avg or not? [twinracer2] [ In reply to ]

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spocket

Jun 28, 11 6:15

Post #4 of 7 (1531 views)

50 watts difference seems on the really high side. I usually get around 10 watts (+/- 5) difference between APz & APnz (z=zeros; nz=non-zeros). But I guess that depends a lot on the terrain and your riding style. I tend to keep the crank moving at all times, pushing also on the downhills (unless I run out of gears).

If I am not mistaken, the easiest way to see the difference (and I see you were trying to do that before the data got corrupt) is to have your Garmin set on APnz. Then upload your data on TrainingPeaks (or WK0+). Selecting your entire workout, you will get the average power including zeros. (APz) Then you can see the difference.

Personally, I keep my Garmin on APnz (non-zero averaging) because for my riding style (and I have confirmed this on both flat and hilly courses), it gets REALLY close to "Normalized Power NP" (usually within 2-3 watts) which Garmin does not offer as a parameter to display. So that's the closest I can get to on-board-NP with my Edge 500. But that may be a different story for somebody with a different riding style than mine. As mentionned, I coast very rarely, and I do not stop much in my training rides.

---------------------------------
T. Guertin / Spocket

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Re: to zero avg or not? [spocket] [ In reply to ]

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TimAndrus

Jun 28, 11 6:22

Post #5 of 7 (1519 views)

this is a 10mile 3lap course that is flat enough to never coast with maybe the exception of the corners (which i will argue 'could' add up to alot of coasting)

i did/do this 10miles twice, each time i had about the same 'lap avg' for the whole 10miles. i don't coast unless i run out of gear (with 53x11 isn't often).

i'm just really bummed i guess that i will never 'truly' know how i did last night from a power perspective. i suspect i improved but not to the extent of 20%.

Tim

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Re: to zero avg or not? [twinracer2] [ In reply to ]

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jaretj

Jun 28, 11 6:37

Post #6 of 7 (1484 views)

50 watts would be less than a 10% improvement for most of us :)

Last edited by: jaretj: Jun 28, 11 6:37

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Re: to zero avg or not? [jaretj] [ In reply to ]

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