Time in power zones riding outside

After training with power indoors over the last couple winters, I finally caved and bought a pair of Garmin Vector 3 power meter pedals. I’ve done a few rides now, and have looked at my power zones in TrainerRoad through the calendar and am surprised how much time is spent in anaerobic, e.g., my ride this morning (about 1h50min), I have 30 mins in anaerobic (26%). The routes I’ve done so far have included shorter punchy climbs (8-15%), and it’s really interesting to see how much my power goes up, whether powering up a hill, or sitting in my easiest gear on a steeper incline (I now get the power to weight ratio thing!). Is it possible to have this much anaerobic, or is my FTP just wrong?

My trainer rides haven’t felt easy (VO2 max intervals always my bane), so I don’t feel like it’s that off. Looking at my Personal Records comparison, the PRs are all from my Wahoo Kickr trainer rides during TrainerRoad workouts, and not from my recent outdoor rides. Any perspectives are appreciated. Trying to paste an invite if it works:

Was this a very hard ride with an IF around 1? On the surface this doesn’t look straight up wrong, but it does look like a crit - tons of surging and resting. But if you got back from this and didn’t feel totally wiped, your FTP might be set a little low :slight_smile:

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Have you compared your KICKR power numbers with your Vectors? In theory they could be off simply from differences in drivetrain loss and measurement point. Do an FTP test with the KICKR as the power source and record the vector data somewhere else and cross compare

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Good question. IF was 1.16. I had a great day of work afterward - my ride was at 5:30 am this morning, and I went right to work afterward. Definitely drank a lot of water, and was hungry during the day…

I did one post-workout spin on my trainer with the pedals. Did the power matching thing after adding the device. With work travel last couple months (often leaving heavy legs), and recent weekend rides, I haven’t found a good time to do an FTP test, but will eventually…

1.16 IF is quite high for an almost 2 hour ride. In theory, 1.0 IF for 1 hour should be your max, plus or minus some fudging because that’s theory and not real life. 1.16 is outside what seems like the reasonable zone of fudge though - I’d bet you’ll be happy with the result of your next FTP test.

That said, I wouldn’t stress too much about it. There’s a tonnnn of discussion on this forum about indoor/outdoor power difference and power meter/trainer differences, and every kind of difference you can think of. I don’t think you need to get into any of that. Keep your FTP up to date by testing every 6ish weeks with the same protocol, or doing manual adjustment if you’re experienced (based on the info you provided, I’d recommend testing every 6-8 weeks for like a year at least before you start manually tweaking). If you’re doing that, don’t stress about outdoor power. It’s super useful and a power meter is a great tool, but it’s just one more source of information in your toolbox.


Another thing to point out here is that it’s very hard to ride steady outdoors, especially if you live in an area with short sharp hills, which it sounds like you do. It takes riders years and years to calibrate their bodies to be able to do steady state efforts on varied terrain. Don’t be surprised or discouraged if a lot of your rides look like this :slight_smile:

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Agree that IF of 1.16 for 2h is probably not possible. That is the rough equivalent of riding at 110% FTP for 2hrs. If you can do that, you should be in France this month :stuck_out_tongue_winking_eye:

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Thanks man! Appreciate the feedback.

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hahahah. Hit some good 20 second power PRs today, but definitely tons of room to grow! 2 months until CX season… that’s my carrot keeping me pushing!

Your pedals are LR or single sided?

From personal experience, I saw a big difference coming from a left only PM going to a dual sided.

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I opted for the dual. On the weekend, I did two longer, climby rides and my left/right balance was higher for left (by 9%), today, I was closer to 50/50. Kind of odd, but interesting to look at, definitely enjoying the data. I look forward to the new TrainerRoad outdoor workout option being rolled out for Wahoo bike computers.

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Something is very very wrong one way or another; 116% FTP might be possible for 10 minutes but no way 2 hours.

Are you using your Vectors on the turbo trainer now? If so, you can turn on powermatch and do a ramp test that should give you a correct number.

Double check that the pedals are installed and calibrated correctly - though the Vector 3s are considered more simple and reliable than the previous generation.

I’m guessing that it is some combination of

  • Pedal PM’s measuring upstream of the trainer
  • Higher FTP outdoors than indoors (pretty common)
  • Recent training has improved your FTP, but not yet verified through a ramp test.

This. I went out for 4:15 with a targeted 4h Z2 today - I managed 2:45 of actual Z2 with a Froome like focus on my head unit displaying power. I do have a narrow Z2 band - 185-212w.

Definitely harder to hold steady power outside but despite that a 1.16 for almost 2 hours suggests that either the ftp is too low or a discrepancy in numbers between the two power sources.

I’d recommend just using power match and your pedals going forward for your source of power so that you can have consistent measurement both indoors and out. And doing a ramp test with that set up as well.

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So I finally did a ramp test, and my FTP barely moved, and I went deep until I cracked. Final ramp I held was 219 W. New FTP is 164, up from 153 (which was from when I was dealing with some chronic fatigue issues this winter). Based on my new FTP, I’d still get an IF > 1 for my rides. I zero my Vector pedals each ride. I’m confused. :woman_shrugging:t2:

Maybe the ramp test isn’t the test for you then? Do you 20 min test with the pedals or even better a 60 min test


Did you record the power from the Kickr and vectors separately?
My Kickr reads nearly 30 watts lower than my power meter during an FTP ramp test. In comparison, the Neo 2 I bought to replace it gives me a 6-7 watt difference which would account for drive train losses.

I’d hazard a guess that your Kickr is doing something similar. Before ditching the Kickr I had to manually adjust the FTP for my outdoor rides to get any useful comparison in the TR app.

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I’d try a couple things:

  1. compare kickr power to vector power like some people are suggesting. If you’re not familiar, an easy way to do this is to do your TR ride as normal (reading kickr power), and also record it on your head unit (reading vector power) and then compare the two files using dcrainmaker’s tool. If they’re consistently off, as it sounds some people’s are, then there’s yer problem

  2. for your TR rides, do you pair your power meter as the power source? if not, that’d be a good thing to try too.

  3. if they’re super off, you can configure your kickr to use your vectors as the power source (rather than the internal kickr power meter) all the time (not just in TR rides). You can do this in the wahoo app, and it’d guarantee you’re using the same power source inside and out. FWIW, I use a kickr snap and chose not to do this, but I also haven’t had issues with power discrepancy. YMMV.

And finally from a non-hardware perspective, it’s possible you’re just a very punchy rider and/or your muscular endurance is underdeveloped. I don’t know your training history, but anecdotally I think it’s pretty common for this to be the weakest part of a rider who’s new to training with power - I know it was for me (still is? :wink: ) Your threshold can appear low causing IF to appear high if you’re not used to cranking out steady hard efforts like you’d do in an FTP assessment, ramp or otherwise.

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