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Target watts for IM
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For my long bike rides for Ironman prep, I have been training at about 73% of my FTP. However, the 73% is based on my normalized power compared to FTP. My average watts is always a little bit lower than normalized power for longer rides. So, if I compared average watts to TFP then I think my percentage would be slightly lower. I want to ride about about 70-71% of my FTP for my upcoming Ironman.

My question is, should I use normalized power or average power to calculate riding intensity as the percentage of FTP? Secondarily, why use one or the other as the measuring point?

Thanks.
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Re: Target watts for IM [rustyb04] [ In reply to ]
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If it's a flat course, use average power.

For hilly courses you'll probably get mixed responses.

Personally, I just aim to see the target number whenever I look down. E.g. If I'm trying to ride at 200w I'll try and hit that every time I'm looking down. If half way through the bike leg I'm averaging/Np-ing 195w, I don't try to 'make-it-up'. Conversely if I'm climbing a hill and I'm over the target for a few minutes, I don't freewheel to bring the average/NP down.
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Re: Target watts for IM [rustyb04] [ In reply to ]
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This page has a good chart in it for you...

https://www.trainingpeaks.com/blog/how-to-cheat-by-using-a-power-meter-in-an-ironman/




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Re: Target watts for IM [rustyb04] [ In reply to ]
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I'm a newbie asking the same questions, but it is my understanding that NP is ultimately the equivalent physiological effect on the body. It's likening the effort you put out by taking into consideration power surges and comparing it to an equivalent steady state effort. Since your FTP test itself is a steady state effort that's what you have to compare to. You can't assume you can increase your average watts on a variable ride as it is obviously burning more matches as indicated by the higher NP. But for an IM bike leg, you should be pretty close with NP to AP, so the percentage difference as a percentage of FTP shouldn't be all that much different. I know that's something I've been practicing and still haven't perfected on a fairly rolling training loop (still around 1.1 VI). So my strategy is to just stick with what I've been able to put out in training from an NP perspective. Hopefully can get that AP up, but will not allow the NP to go higher than I've done in training. Race course is considerably flatter and certainly more consistent (not constantly rolling), so I have faith I can average more watts while keeping NP consistent.
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Re: Target watts for IM [tridave101] [ In reply to ]
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tridave101 wrote:
This page has a good chart in it for you...

https://www.trainingpeaks.com/blog/how-to-cheat-by-using-a-power-meter-in-an-ironman/




x2, this is a great read. Using TSS and IF are good guides and both of these are based off of NP, not AP. If you ride perfectly steady state (e.g., flat course, no wind direction changes), then AP=NP but otherwise NP will always be higher; there MAY be very specific, short effort scenarios where this doesn't hold true but those are outside the the usefulness of NP as a metric IMO.

If you've been training to 73% NP/FTP (by the way, this is the definition of IF) with success then I'd stick with that. Worst case is you slightly under-bike and have some fuel left in the tank for the run. A whole lot better than the alternative...
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Re: Target watts for IM [rustyb04] [ In reply to ]
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It's always better to be a few % lower on the bike than planned, especially in your first IM. Just 5-10 watts too high can make the run more of a death march near the end. 'Loosing' a few minutes with a somewhat conservative bike can lead to gaining much more time by having a successful run.

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Re: Target watts for IM [rustyb04] [ In reply to ]
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Is NP a trackable statistic using PM/Computer? I've not looked if being honest, but I always just watched current power and tried to keep it near the % ftp of my goal. Is average power for the ride a field on most garmins?
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Re: Target watts for IM [cmd111183] [ In reply to ]
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There's several power metrics available if I recall correctly. Avg power, NP, 3 sec power, and 10 sec power are few that come to mind.
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Re: Target watts for IM [cmd111183] [ In reply to ]
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Yes, my head unit displays 3 sec average, lap average power and lap normalized power. my computer auto laps every 10 miles. That way I can get a good gauge on what I've done for the last 10 miles and can also get a feel for how variable my output is by comparin AP to NP.
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Re: Target watts for IM [rustyb04] [ In reply to ]
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rustyb04 wrote:
For my long bike rides for Ironman prep, I have been training at about 73% of my FTP. However, the 73% is based on my normalized power compared to FTP. My average watts is always a little bit lower than normalized power for longer rides. So, if I compared average watts to TFP then I think my percentage would be slightly lower. I want to ride about about 70-71% of my FTP for my upcoming Ironman.

My question is, should I use normalized power or average power to calculate riding intensity as the percentage of FTP? Secondarily, why use one or the other as the measuring point?

Thanks.

I would use NP. If you use AP, you feel like you are "penalized" for coasting, when in actual fact you're saving energy when coasting above a certain speed (I coast when going over 30 mph). It all adds up to quite a bit. At IM Los Cabos back in 2013 (hilly, not much flat) I had 15 min of zero watts due to resting on the downhills. On a flat course, AP and NP should be pretty close anyway since you should be pedaling most of the time.

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Re: Target watts for IM [tridave101] [ In reply to ]
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Is there a way to make the table useful for other distances, like half distance, Olympic and sprint?
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Re: Target watts for IM [rustyb04] [ In reply to ]
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I'd use NP and make sure you've taken TSS into account. For an IM, I know I can run fairly well if I keep the TSS under 280, which aligns with that chart at the link above. But the IF to achieve TSS=275 at IMFL will differ from the IF to achieve TSS=275 at IMC, for example. How long you'll be on the bike pushing that power is key.
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Re: Target watts for IM [rustyb04] [ In reply to ]
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Another vote for NP.

BTW, if you look at the chart you will notice that the recommended range of FTP percentage is based on the duration of how long you will be on the bike. Obviously, to use the chart you need to have an estimated duration (I know this sounds like a chicken and egg issue -- how can you know duration if you don't know power? but if you have a good sense of your pace for different levels of power you can plug in a couple of tries and triangulate on a power, pace and duration). BUT you should be prepared to adjust on race day. For example, if it is a windy day your power will produce less average speed than on a calm day (unless the course is one way, mostly downwind). In that case, even though you will be tempted to ride harder to make up for the wind, what you need to do is power back a little because you will be out there longer.
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Re: Target watts for IM [mebwessel] [ In reply to ]
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you could probably expand the table with your own data if you track your data... for other distances i just go by %ftp or (IF) as a guide and up or down it depending on conditions.


Race distance% of FTPSprint90–105%Olympic85–95%Half-Ironman75–85%Ironman65–80%
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Re: Target watts for IM [rustyb04] [ In reply to ]
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NP, devised by coggan, for me is too generous - it overestimates what I could do (eg on on a hilly or intense on/off ride where the NP is quite a bit higher than AP)
Weighted Average Power, as used by strava (I think derived from skibas xpower iirc and used by GC) is maybe too stingy and underestimates what I could do on a steady sate ride.
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