# Zero Averaging? Non-Zero Averaging



## OldZaskar (Jul 1, 2009)

Two other guys in my club ride with power meters - I just got mine in January. Coincidently, the three of us are very closely matched in fitness - overall anyway (one guy has a relatively low 10 second max power... which means nothing... except it's fun to make fun of).

Okay, the point... We argue about whether to collect/read the data based on averaging the zeros or not. They don't average the zeros... nets very impressive numbers. I average them. It seems pretty simple...

If you ride up a mountain (10 miles) and average 400 watts, then coast back down, you've ridden 20 miles with an average power output of 200 watts. The only way to claim you averaged 400 watts (non-zero averaging) is pedal down that mountain averaging 400 watts...

So, why would one set their computer to: Non-Zero Averaging? Would this be for specific training/testing? 

But again, I've been using a power meter for a few weeks, and am only part way through Allen and Coggan's book.

Thoughts?


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## rockdude (Apr 3, 2008)

The standard is to collect the zeros for average power.


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## woodys737 (Dec 31, 2005)

Not sure? Data would be useless imho as you want to compare power relative to you to see if you're going in the right direction or not.


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## Poncharelli (May 7, 2006)

For zone 2 rides, I like looking at "zero-power percentage". 

If i can hit less than 30% zero power pedaling, that indicates I held my target pretty good, and that the route is good for zone 2 rides. Hills usually cause a lot of zero power pedaling. 

Joe Friel says that 40% zero power pedaling is typical, for base rides. Which I found suprising.


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## Undecided (Apr 2, 2007)

Poncharelli said:


> For zone 2 rides, I like looking at "zero-power percentage".
> 
> If i can hit less than 30% zero power pedaling, that indicates I held my target pretty good, and that the route is good for zone 2 rides. Hills usually cause a lot of zero power pedaling.
> 
> Joe Friel says that 40% zero power pedaling is typical, for base rides. Which I found suprising.


I try to keep it under 3% for long base rides, which means making some of the least interesting routes possible in a generally beautiful place to ride. But, I've always figured that the constant and steady effort is what those rides are all about.

Sort of relatedly, after I switched from a PT to a Quarq, I noticed an increase in (zero-average) power displayed on my Garmin (vs. similar rides on the PT), but not in WKO+. I have guessed that this means the Quarq doesn't broadcast zeros for the Garmin to record (broadcasting nothing for the power field, I suppose), but that WKO+ fills them in, but curious as to whether anyone here knows more about that.


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## kbiker3111 (Nov 7, 2006)

The only guys who really use non-zero averaging are CX racers since they're usually running when they're not pedaling, which is not the same as coasting.


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## zender (Jun 20, 2009)

OldZaskar said:


> They don't average the zeros... nets very impressive numbers. I average them. It seems pretty simple...


Since not pedaling allows you to recover for the next effort, ignoring those zeros doesn't really reflect your fitness. Your body is metabolizing lactate during those descents.

Using average power to measure your fitness assumes that an increase in power results in a linear decrease in your ability to sustain it. It's not linear but exponential to the 4th power. Normalized power (which counts zeros) rather than either average power calculation (with or without zeros) makes more sense to me. I know it's not completely accepted by everyone.


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## the mayor (Jul 8, 2004)

kbiker3111 said:


> The only guys who really use non-zero averaging are CX racers since they're usually running when they're not pedaling, which is not the same as coasting.


I'm not following you on this??
You coast a LOT in cross...braking, through corners, down hills and setting up for dismounts.
You'll find you pedal for under 30 seconds average in cross


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## kbiker3111 (Nov 7, 2006)

I know, but you also run.

I'm not saying it makes sense, I'm just saying thats the only place where it seems accepted practice.


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## Poncharelli (May 7, 2006)

Undecided said:


> I try to keep it under 3% for long base rides


Actually I misspoke earlier. I meant 30-40% non-Zone 2 power. Much different than zero power. Joe Friel said that most his athletes hit about 60% zone 2 during base rides (with 40% going above and below). 

looking at a recent file, i had 6 minutes of zero pedaling out of 2 hours (looking at those power bins). Much different. that would be about 5%. 

thanks for making me realize my screw up there.


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## Undecided (Apr 2, 2007)

zender said:


> Since not pedaling allows you to recover for the next effort, ignoring those zeros doesn't really reflect your fitness. Your body is metabolizing lactate during those descents.
> 
> Using average power to measure your fitness assumes that an increase in power results in a linear decrease in your ability to sustain it. It's not linear but exponential to the 4th power. Normalized power (which counts zeros) rather than either average power calculation (with or without zeros) makes more sense to me. I know it's not completely accepted by everyone.


As soon as Garmin releases the related update to the Edge 500, I'll probably include NP on one of my screens.


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## the mayor (Jul 8, 2004)

kbiker3111 said:


> I know, but you also run.
> 
> I'm not saying it makes sense, I'm just saying thats the only place where it seems accepted practice.


You only run 10-20 seconds a lap....unless it's a mud bath.
The few time I ran a SRM on my cross bike...it was about 50/50 pedaling to coasting ratio.
And the average pedal time was under 30 seconds at a time.
I think Adam Meyerson had some files posted...but I'm too lazy to look for them or mine from a few years back
What you would look for in a cross file are the spikes


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## Jay Strongbow (May 8, 2010)

I don't use one but if it did I'd want to measure my power output and I don't consider coasting to be power output any more than I would stopping for a coffee. Not counting 0 makes total sense to me. then again so does factoring it in. It just depends what you are trying to get out of the thing. It goes without saying that if you just use the data to compare it with other people you'd need to use the same method.


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## Alex_Simmons/RST (Jan 12, 2008)

OldZaskar said:


> If you ride up a mountain (10 miles) and average 400 watts, then coast back down, you've ridden 20 miles with an average power output of 200 watts. The only way to claim you averaged 400 watts (non-zero averaging) is pedal down that mountain averaging 400 watts...


Well the average would be higher than 200W since average power is calculated based on time, not distance, and the time spent going up would be much more than going down the other side. But we get your point.



OldZaskar said:


> So, why would one set their computer to: Non-Zero Averaging?


Perhaps they have ego issues. 

There is no training/racing reason to use NZAP. It's a meaningless number since the time spent not pedaling affects what you can do when you are pedaling. I could do a series of 1 minute efforts with 15-min breaks and have the world's best 20-min NZAP. What's the point of that? It tells me absolutely nothing about my ride, nor my capabilities. And there is no actionable intelligence to be gained from it.


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## stevesbike (Jun 3, 2002)

Alex_Simmons/RST said:


> Well the average would be higher than 200W since average power is calculated based on time, not distance, and the time spent going up would be much more than going down the other side. But we get your point.
> 
> 
> Perhaps they have ego issues.
> ...


good point - and numbers are to help you get faster, not to brag to friends. That's what Strava is for!


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## Jay Strongbow (May 8, 2010)

Alex_Simmons/RST said:


> Well the average would be higher than 200W since average power is calculated based on time, not distance, and the time spent going up would be much more than going down the other side. But we get your point.
> 
> 
> Perhaps they have ego issues.
> ...



I agree that that would tell you nothing about your capabilities. But I don't feel that averaging in coasting, or even backing off, tells you anything more about your capabilities. A flat ride is one thing but let's face it on hills there are times when it safer and smarter riding to back off or it's just plain faster to not pedal and get into a tight tuck despite the "keep pedaling" mantra you hear so often on the interwebs. When someone would rather not go over a cliff thats not necessarily a reflection of capabilities. I suppose it boils down to there are only certain type of rides where a power meter can give you anything meaningful as a reflection of capabilities regardless of it you factor in 0 or not. And rides that include steep curving down hills or drafting ain't those type of rides.


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## zender (Jun 20, 2009)

Undecided said:


> As soon as Garmin releases the related update to the Edge 500, I'll probably include NP on one of my screens.


That would be cool. Though, I don't think any of that stuff is needed on the fly. It's perfectly adequate to crunch the numbers after a ride.


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## Gatorback (Jul 11, 2009)

If the purpose of using a power meter is to track your training and the work performed, ignoring the zeroes makes no sense to me. If you want to figure out how much you can average over a certain time period, go do a time trial--otherwise the zeros seem to be important data that you need to account for with your rides. Otherwise your training will be less exact and you can't as accurately compare improvements over time. 

I'm curious why those guys who look at their average power without the zeroes on an uphill just wouldn't isolate the uphill to see how they did there, which they can track, and then also look at the whole ride with the zeroes in there, which is important data also.


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## looigi (Nov 24, 2010)

It's up to you, of course. If you don't consider coasting down the hill after a climb part of the training, don't average it in. There's a popular long climb I know where riders will have somebody meet them at the top to pick them up and drive down. They don't average in the drive down, and not much point in averaging a ride down if it's just coasting. If coasting is integral to a training ride, then average in.


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## Alex_Simmons/RST (Jan 12, 2008)

Jay Strongbow said:


> I agree that that would tell you nothing about your capabilities. But I don't feel that averaging in coasting, or even backing off, tells you anything more about your capabilities. A flat ride is one thing but let's face it on hills there are times when it safer and smarter riding to back off or it's just plain faster to not pedal and get into a tight tuck despite the "keep pedaling" mantra you hear so often on the interwebs. When someone would rather not go over a cliff thats not necessarily a reflection of capabilities. I suppose it boils down to there are only certain type of rides where a power meter can give you anything meaningful as a reflection of capabilities regardless of it you factor in 0 or not. And rides that include steep curving down hills or drafting ain't those type of rides.


Sure but all that extra coasting (necessary or not) still impacts the power you can sustain when you _can_ pedal, so as a means to provide insight into your ride, the overall average power should include the entire ride.

Of course one can look at the climbs on their own as a means to assess power capabilities for those individual shorter duration intervals.

But the overall NZAP from such a ride is *not* an indicator or what one can actually do for that duration. It is meaningless and provides no insight.

Perhaps I should ask a question:
What insight into one's capabilities does NZAP provide?


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## zender (Jun 20, 2009)

Alex_Simmons/RST said:


> What insight into one's capabilities does NZAP provide?


That's an easy one: It makes your average power look higher than you can actually sustain so you can brag to your buddies.


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## Alex_Simmons/RST (Jan 12, 2008)

zender said:


> That's an easy one: It makes your average power look higher than you can actually sustain so you can brag to your buddies.


I suppose then it provides insight into one's psychological state, but not their physiological capabilities.


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## bikerat (Oct 29, 2012)

I don't mean to reopen a can of worms that appears to have been closed for awhile but as usual I was looking up something else and this thread caught my eye. So my two cents...

The reason I use non zero averaging for interval training is because I can't always train in an ideal place that let's me pedal constantly over the entire distance. There are a few places on my route that I have to slow down for either pedestrians or going through a blind corner which requires momentary lapses in pedaling which obviously cause zeroes. Depending on the length of the interval, a few lapses (although they are very short at around 10-15 seconds) in pedaling may reduce my average power by 5-15 Watts as the effect of the zeroes are significant. If I'm trying to maintain 285W and my heart rate is pegged at sustainable threshold then potentially I could blow myself up trying to 'make up' for the zeroes. As long as the pedaling lapses are short and there is not any discernible recovery to heart rate then I believe using the non zero power average is more appropriate as long as you are truly trying to minimize non-pedaling time.


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## Alex_Simmons/RST (Jan 12, 2008)

bikerat said:


> I don't mean to reopen a can of worms that appears to have been closed for awhile but as usual I was looking up something else and this thread caught my eye. So my two cents...
> 
> The reason I use non zero averaging for interval training is because I can't always train in an ideal place that let's me pedal constantly over the entire distance. There are a few places on my route that I have to slow down for either pedestrians or going through a blind corner which requires momentary lapses in pedaling which obviously cause zeroes. Depending on the length of the interval, a few lapses (although they are very short at around 10-15 seconds) in pedaling may reduce my average power by 5-15 Watts as the effect of the zeroes are significant. If I'm trying to maintain 285W and my heart rate is pegged at sustainable threshold then potentially I could blow myself up trying to 'make up' for the zeroes. As long as the pedaling lapses are short and there is not any discernible recovery to heart rate then I believe using the non zero power average is more appropriate as long as you are truly trying to minimize non-pedaling time.


Conversely, you may well be short changing yourself, since the time spent not pedalling affects what you can do when pedalling (you are getting some mini recovery despite what your HR says - it's way too slow to respond to things like that). IOW you may well be capable of going harder in the "on" portions. But it may be that being right on the limit is not the intent anyway.

I would be using what I'm doing "now" as a guide, rather than a cumulative rolling average in any case. I only look at interval averages after the interval is done (which is often later on when I'm home).

In the end, whatever works for you and as long as you are riding at the intended level overall, that's what matters. Finding routes that allow for non-stop pedalling can be a challenge for many people.


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## serious (May 2, 2006)

If you are working on intervals, then non-zero averaging makes perfect sense, unless your computer can capture the average power over the intervals and the overall value. If you are concerned with overall results, the you want the nominal power to reflect reality, I would think.


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