New power meter by next week... how to set up FTP?

Hi, I will have a new Sram powermeter within a week or so. I know that FTP is totally different indoors and outdoors. Is there a tip to try to match your indoors ftp with outdoors? Maybe adding a 10% or so to my outdoors ftp?? I know the best way it is to do an outdoors ftp :crazy_face::woozy_face: but I don’t like the idea :joy:
Any suggestion?

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I don’t think there is a difference, check out this article: Indoor FTP vs. Outdoor FTP: Why They Feel Different (But Aren't) - TrainerRoad Blog

I would either use your on bike power meter indoors or use the tool suggested in the article or something like DC Rainmaker’s analyser tool to compare the power meter and trainer to understand how they read releative to each other.


Personally, my “Indoor FTP” is lower than my “Outdoor FTP” by about 10%. However, this is only evident under very controlled conditions. If you have long, steady climbs on which to do your training, I would do a 20 minute test on one of them to determine FTP outside. If this isn’t the case, I wouldn’t bother changing it from indoor to outdoor. Structured training outside is hard enough as it is, so if you find some intervals too easy at times, just go a bit harder. The difference between holding a set power on a trainer or a steady hill and holding a set power on semi-flat or rolling terrain is palpable. Personally, I don’t have any long climbs on which to train, so I have to set my power targets a bit more loosely and pay more attention to RPE.

Ignoring the indoor vs outdoor aspect to a degree… my first question is:

  • What are you using for power right now and how does that differ compared to your pending SRAM power meter?

Short answer is that anytime you change your primary power data device (trainer and/or power meter), a new FTP test is usually appropriate. There are many reasons that even the best devices will not “match” so it’s not safe to assume that your FTP is the same on all devices. Hence the recommendation for a test to cut out the variables and unknowns.

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First and foremost, recognize that FTP is an operationally defined characteristic, and ANY measurement has error. It also varies from day to day, so whether you use AI FTP (my recommendation), or some other method (5,8,20,60 minute test, ramp test, etc.), you’re getting a rough estimate on the day and the conditions you tested.
Where FTP matter is in providing a quantifiable measure of progress over time, and giving your useful targets for training.
If you’re going to use TR to direct your training, you’ll get the best results if you use the method their model works best with. But whatever method you use, be consistent and measure the same way each time, so at least your error stays relatively constant.

I struggle with longer threshold indoors, I can ride at similar powers in the saddle (out the saddle I can make way more power outdoors)

As I am a fairly big dude I heat up a lot doing threshold and it makes it rather uncomfortable

Hey there!

As others in this thread have already said, your best bet is likely going to be doing an FTP/Ramp Test to establish your zones with your new power meter.

Once you’ve established your zones with your new power meter, you could probably stick to using AI FTP Detection down the line. Because AI FTP Detection analyzes all of your recent training data and goes beyond individual capacitive efforts, most athletes with multiple power meters have found it highly accurate for setting the right FTP for their training. Additionally, the more data AI FTP Detection gets with your new power meter, the more accurate it will be in your future training.

Your power numbers should be pretty close when comparing inside vs. outside workouts. Cooling is often the biggest factor that comes into play when athletes note discrepancies between their indoor and outdoor power data, so here is a TR Blog article on the subject that might help you out with your indoor training setup:

If you’re using a smart trainer with your power meter, make sure that PowerMatch is enabled. That will allow you to get your power data from your power meter while still taking advantage of automatic resistance changes from your smart trainer.

Hope this helps! Feel free to let me know if you need a hand with anything else. :slight_smile:

So it seems a test on the road must be done :hot_face: