Workouts effective at considerably lower FTP indoors?


it makes me wonder, i can’t hit my outdoor FTP indoors by far. Its 299 vs 235 which makes me thinking those TR workouts are not very effective. The workouts only feel challenging for my body not really for my muscles. Do you think this way i will get much from the workouts ?

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Are you suggesting to lower your FTP to match your “indoor” ability?

If so, that is the wrong approach. You will not be pushing your body enough to really get the desired adaptations.

You should be looking at the reasons you have such a disparity between inside and outside.

  • Cooling
  • Position
  • Motivation

Look at these and others and make darn sure you are doing everything in your power to eliminate those from being restrictions or limitations to your power output while inside.


Mine isn’t that far off. Last check which was roughly a month ago I was within 15 watts. Lower inside but I am sure that’s due to where my power is being measured indoors vs outdoors.

Most people have a different indoor to outdoor FTP, and it’s been mentioned a fair bit on the forum - you could try searching and reading on other peoples experiences. If you do the indoor Ramp Test to set your TrainerRoad FTP this is the value you should use indoors - FTP is just a value TR uses to set your training levels. FTP it often receives slightly too much importance as in bragging rights, etc.

if you were new to indoor and structured training the test might need to be taken several times until you get familiar with pushing your self hard on the test. I think I made three attempts each higher before I considered I had it about right. The differences can be down to environmental (cooling) and motivational but can also be quite individual. I know my max. Heart Rate so if I’m pushing myself hard I’m hitting something very close to my Max. Just like going as hard as you can on your favorite hill - you go hard and deep.

I am aware i am not the only one who isnt able to reproduce the power inside. Its just the range, i mean i would accept something like 280.

On the ramptest hit 190 bpm which is close to my 194 max. But its frustrating i mean i hit like 310 at the last stage but outdoors i did 315 avg for 20 mins.

I think Chad could be right cooling could be a problem since i am using a normal desktop fan.


A good fan is very much the biggest upgrade you can make to your indoor training setup!


Yeah, a desktop fan isn’t going to make much of a difference. I have two powerful fans going in a (roughly) mid 60 degree F basement and I could still use more cooling sometimes. Especially at wattages approaching 300w, where I believe the amount of heat our body produces is higher (I think I’ve read that for every watt, we give off 3 times that amount in body heat).


OP, how are you measuring power inside and outside?

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That’s the next logical question - actually, the first one.

I am using a Quarq PM outdoors, indoors the PM is connected to Wahoo Kickr via Auto-Match.

You will. Buy yourself a fan or two for start. And do your indoor workouts based on your indoor’s FTP.

I had the same problem. First workout I did at my outdoor’s ftp of 280 W and couldn’t finish. I did a ramp test and got 226 W. A couple of workouts in I did another with 255 W result. Last time I tested (3 months of indoor training) I ended up with 273 W while my outdoors is a little above 290 W now. Part of the improvement inside was just getting used to the trainer and fixed position. That is pretty quick and you could retest in two or three weeks. The remaining difference for me is a different position on the bike - my best power is on climbs.

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Even allowing for the inadequate cooling that seems like a crazy big difference. Especially on the Ramp Test where you’re really not working hard for that long - world be more understandable if you were doing the 20 minute test which is long enough to build up some real overheating problems.

You sure the power match is working OK? Quarq is presumably zeroed/calibrated? If you have 2 ways of recording power (Garmin and an ipad or laptop?) then maybe worth turning off the matching and seeing what numbers you’re getting from the Quarq and Kickr respectively.

And yes, none of this should stop you buying at least one and preferably 2 powerful fans ASAP…

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Purely anecdotally (read: might be BS) but based on my own experience, you can adjust/adapt to the difference in temperature indoors.

I’m a much, much better rider in the summer/warmer weather now, a change that has come along with an increase in the amount of time I spend on the trainer inside, where it’s considerably warmer than outside! I’ve been doing indoor rides for a few years now, and only just got a big fan.

I think this is one of the places we find a lot of early gains when training regularly indoors; something to think about when considering testing in your early days maybe.

What protocol are you following to determine your FTP when you are outdoors?

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This +1.
I use a Garmin edge unit and notice I get big differences depending on which app I use for outdoor FTP. If I go off of the Garmin it will vary greatly in its estimations day to day.

I get why the OP would be trying to figure out what’s going on. Big difference.

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i simply lap 20 min on a road and cut 5% off my avg lap power. i got 315 on the lap so 5% off resulted in 299

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I will do a test if the power reported to trainerroad matches the data reported from my PM to the headunit.

Did you do a prep like the warm-up and burn off efforts like the proper 20 minute test?

If not, what if any warm-up did you have before the 20m effort?

Point being, you may well have given yourself an overly inflated value without the appropriate lead in to your 20m effort.

It’s about 90 min to ride to the starting point of that road.

Then I don’t think it is appropriate to use the 0.95 multiplier to estimate your FTP.

That 0.95 value is linked directly to a particular test protocol that must be followed in order for the data to be accurate and meaningful.

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