Powertap questions

James_London

Alex_Simmons/RST wrote:

James_London wrote:

Garmin average is NZAP (non-zero average power)

That's a pretty bad oversight by Garmin and one they appear not to be all that interested in fixing.

Alex, there's a fix in place. DON'T STOP PEDALLING!

If you're road/ circuit racing, checking your average should be the least of your worries! I fyou're TT'ing you won't stop pedalling hopefully.... :-)

liversedge

I think NZAP is kind of interesting during a ride - it tells you how hard you're going*. I'd be more interested in Garmin showing NP and TSS than fixing the AP display. I heard its something they are looking at ...

* ok for me living in a hilly area some coasting/freewheeling is largely enforced. In a bunch ride or when 'slacking' maybe NZAP is less useful?

Alex_Simmons/RST

I cannot think of a single circumstance where NZAP tells you something of value.
Time not pedalling/coasting impacts your ability to produce power when you do pedal.

AP and NP are far more useful metrics.

guinea

Here's some of the data

Should I set either Nom Power or Average power as my threshold power now? The default was 239 which on this evidence is too low as it makes my IF very high. I guess my IF should be 1, no?


Entire workout (74 rpm):
Duration: 58:43
Work: 1011 kJ
TSS: 158.3 (intensity factor 1.272)
Norm Power: 304
VI: 1.06

.....................Min...............Max................Avg
Power:...........1...................662................287 watts
Heart Rate:....100..............190................167 bpm
Cadence:.......2.................21.................75 rpm
Speed:..........11.4..............72.6................32.7 kph

jonginge

guinea wrote:

Here's some of the data

Should I set either Nom Power or Average power as my threshold power now? The default was 239 which on this evidence is too low as it makes my IF very high. I guess my IF should be 1, no?


Entire workout (74 rpm):
Duration: 58:43
Work: 1011 kJ
TSS: 158.3 (intensity factor 1.272)
Norm Power: 304
VI: 1.06

.....................Min...............Max................Avg
Power:...........1...................662................287 watts
Heart Rate:....100..............190................167 bpm
Cadence:.......2.................21.................75 rpm
Speed:..........11.4..............72.6................32.7 kph

I just downloaded WKO+ and looked at the data from my RP laps (see link in sig). The AP and NP were 302 and 312, respectively. The threshold power guesstimated during the config process was about 170W (based on weight presumably). I've reset TP to 290W but would also like to know if this is a reasonable change. Even with this change my TSS from sunday was 300 (not just from the linked laps). I wonder why I'm tired at the end of the commuting week

liversedge

Alex_Simmons/RST wrote:

I cannot think of a single circumstance where NZAP tells you something of value.

I ride hilly intervals which mean go hard / coast / go hard / coast. NZAP is indicative of overall effort climbing and I can watch it drop as I tire. I don't need to bother with laps and don't need to worry about how long each climb or descent is and how that might skew any average power.

Mind you - I'm not generally that interested in the average, it tends to be more about what I'm doing right now. By that token AP is pretty useless too! :-)

Alex_Simmons/RST

liversedge wrote:

Alex_Simmons/RST wrote:

I cannot think of a single circumstance where NZAP tells you something of value.

I ride hilly intervals which mean go hard / coast / go hard / coast. NZAP is indicative of overall effort climbing and I can watch it drop as I tire. I don't need to bother with laps and don't need to worry about how long each climb or descent is and how that might skew any average power.

Mind you - I'm not generally that interested in the average, it tends to be more about what I'm doing right now. By that token AP is pretty useless too! :-)

If you want to know what you are doing on a given part of a ride, then use the interval button. That's what it's for.

Alex_Simmons/RST

guinea wrote:

Here's some of the data

Should I set either Nom Power or Average power as my threshold power now? The default was 239 which on this evidence is too low as it makes my IF very high. I guess my IF should be 1, no?


Entire workout (74 rpm):
Duration: 58:43
Work: 1011 kJ
TSS: 158.3 (intensity factor 1.272)
Norm Power: 304
VI: 1.06

.....................Min...............Max................Avg
Power:...........1...................662................287 watts
Heart Rate:....100..............190................167 bpm
Cadence:.......2.................21.................75 rpm
Speed:..........11.4..............72.6................32.7 kph

1. Was this a maximal effort?

2. for a hard variable ride of about an hour (which this was), then FTP is usually closer to NP than to AP. If it was a hard ride, then I'd lean towards 295-300W as a good FTP estimate. The nearest 5W is good enough.

liversedge

Alex_Simmons/RST wrote:

If you want to know what you are doing on a given part of a ride, then use the interval button. That's what it's for.

Sir, yes sir.

magliaceleste

phips wrote:

There's a thread going on over in Workstop today about TrainingPeaks(WKO) - somebody mentioned SportTracks, and the fact there's a plugin available to do IF/TSS etc. SportTracks is free - might be worth looking into before shelling out on TrainingPeaks.

I have the latter, although I'm going to take a look at SportTracks just for comparison purposes. Others may be able to save money where I didn't

Hi. Sorry to chip in, but see my posts that I made before on this forum about Sportstracks and the Training plug-in which allows you to see power etc.

http://www.bikeradar.com/forums/viewtop ... t=12574321

By the way NZAP really annoys me on the Garmin too.

Cheers

ob

Does anyone know if WKO+ allows you to change your body weight over time, so that you could see, for example, an increase in Watts/kg on a graph, without increasing Watts.

I've got the trial version, and I only seem to be able to change the weight without charting weight progression.

BeaconRuth

ob wrote:

Does anyone know if WKO+ allows you to change your body weight over time, so that you could see, for example, an increase in Watts/kg on a graph, without increasing Watts.

I've got the trial version, and I only seem to be able to change the weight without charting weight progression.

You can enter a different weight for every ride you do, no problem. You just change it in the journal page for that ride.

Ruth

Alex_Simmons/RST

BeaconRuth wrote:

ob wrote:

Does anyone know if WKO+ allows you to change your body weight over time, so that you could see, for example, an increase in Watts/kg on a graph, without increasing Watts.

I've got the trial version, and I only seem to be able to change the weight without charting weight progression.

You can enter a different weight for every ride you do, no problem. You just change it in the journal page for that ride.

Ruth

Yep, and if you have a more permanent change in body mass, then just change the value in your athlete page and each new workout will use that new default mass (which, as Ruth says, you can over write for each file).

bahzob

Since this topic has come back to life I'll just correct the erroneous view that power meters cannot be used for race pacing.

If you are comfortable using them they can, very effectively, provided that the chosen event requires periods of steady state type activity. Examples are TTs, sportives (especially those with long climbs like Etape) and breaks in road races.

What's more having a clear idea of power demands and pacing strategy of an event allows you to train effectively for it and learn after an event to improve next time.

OP: I've got some specific examples of how to use a powertap to pace for the Marmotte. Let me know if you get one and are interested.

guinea

Hello. OP here.

I have the PT and am interested in any info you have.

Feel free to share here or take it to PM.

Thanks again all, there's been some great info in this thread.

bahzob

I've put some thoughts here

http://mr-miff-on-tour.blogspot.com/2009/04/marmotte-power-pacing-guide.html

Might seem a bit complicated if not used to power training but boils down to

Find your FTP
Plan to climb somewhere around 65% to 85% of this depending on how confident you feel
Train by doing some rides at these levels for 1-2 hours. Over time do more than 1 per day with a rest between.
Supplement with some FTP training (time trials also good training)
Depending on results of training put together a plan for the actual event.
Ride to this plan but be flexible in case of unexpected.

Pretty much cover the approach I took last year. Hope it helps.

Alex_Simmons/RST

bahzob wrote:

Since this topic has come back to life I'll just correct the erroneous view that power meters cannot be used for race pacing.

If you are comfortable using them they can, very effectively, provided that the chosen event requires periods of steady state type activity. Examples are TTs, sportives (especially those with long climbs like Etape) and breaks in road races.

What's more having a clear idea of power demands and pacing strategy of an event allows you to train effectively for it and learn after an event to improve next time.

OP: I've got some specific examples of how to use a powertap to pace for the Marmotte. Let me know if you get one and are interested.

Indeed. In fact, it is the events where you are riding sub-maximally where the most gains (or the biggest losses) are to be made. Etape and similar but also very long TTs and Ironman racing. I say that from having examined pacing from many many long TT type efforts.

The reason for that I have surmised is that it is easier to overcook it when going sub-maximally, whereas in a shorter TT (the opening minutes aside) you are pretty much at the limit and it's harder to overcook it (and certainly if you do there is a self correcting mechanism in the body that kicks in reasonable quickly).

In very long events, that mechanism may takes hours to show it's ugly head and by then it's way too late.

Pacing strategy can be pre-determined with a known course profile and knowledge of one's power capabilities. I do however prefer to use more than just FTP on which to base that on (IOW use mean maximal power from previous longer efforts if known).