Outdoor vs indoor ftp question

If I do an ftp test outdoors and get 212 but do one indoors and get 176, should I change my ftp in the settings when I go from indoor to outpost and vice versa for each ride, or how should I do that?

Was that using the same power meter? Was your indoor cooling adequate? That seems a very large discrepancy,. I’d be investigating that first.


One of those numbers is only 83% of the other. :man_shrugging:t2:

A maximum of one of them is a good number for your FTP.

I’m not sure what you mean by that.

One was with my 4iii and one was with my hammer. But the 4iii was reading the same on my Garmin as my hammer was on my computer.

The bigger difference may be Garmin testing protocol outdoor vs trainer roads indoor ramp test. Since tr doesn’t let you push their ramp test to Garmin

I mean they can’t both be your FTP

Do a long-form FTP test (either indoors or outdoors) and get a number. Use that number.

I was going to say: if the OP doesn’t have a fan, they should use one immediately. Gross efficiency when cycling is something like 22% - that means that for most trained cyclists, 22% of every watt generated by the body makes it into the cranks or the smart trainer flywheel (wherever you’re measuring power). The balance is wasted as heat. Overheating will tank your power generation.

1 Like

I used one but it’s just a normal pedestal fan. Not a fancy lasko or headwind super powered one

Not a huge problem unless you feel really hot and are sweating buckets.

If your cooling is inadequate, you’ll know already.

I have two big air-mover type fans because I sweat just thinking about throwing my leg across the bike. :smile:

1 Like

Based on this info, I’d bet that your cooling for your indoor rides isn’t as good as it could be. As other athletes mentioned, cooling is SUPER important when it comes to successful trainer sessions. If I don’t have a good fan when I’m training indoors, even Zone 1 feels like a slog.

I don’t think you should change your FTP between indoor and outdoor rides each time – that would be a drag and it would also confuse Adaptive Training & AI FTP Detection, which would probably have a negative impact on your overall plan.

What FTP assessment did you do for the outdoor test? I checked out your account and it looks like you did a Ramp Test for your indoor assessment. If you did something like the 20-minute test that’s commonly used, I bet your FTP is probably closer to 212 and that you weren’t able to push quite as deep inside due to inadequate cooling.

If your outdoor test protocol was reliable, I’d recommend sticking with 212W as your FTP. Then, look into getting a fan that can move a lot of air for your indoor sessions – it may sound crazy, but something industrial strength is what you should look for! I personally use a blower fan that’s “normally” used for water damage in buildings – it moves a TON of air over me and it makes a huge difference for my indoor riding.

Hope this helps – feel free to let me know if you have any additional questions!

1 Like

Thank you for the informative response. The outdoor test was the ftp test built into Garmin units. Using my 4iii left side arm. It’s sort of like a ramp test but works a little different from the tr one.

1 Like