Indoor training struggles (wasted, headache,...)

Hi all,

I just recently purchased a smart trainer and was riding for the second time yesterday, somehow I really have problems with indoor training and was wondering if you have input that could help me.

First to the setup:
I use a wahoo kickr core controlled by the trainerroad app and power readings from my quarq dzero powermeter (same bike and powermeter I use also outdoors). For cooling I have a huge fan directly in front of me and the window open, room temperature was below 15 degree celsius.

Now to the problem:
I really struggle! The first workout I did on Sunday a week ago was McAdie +1, I could only finish it at 80% intensity and was destroyed afterwards and three days after (even had fever one day). Outside, using the same powermeter I don’t struggle with the Over/Unders, I was already considering increasing my FTP because they are not really challenging outside.
After nearly one week break I tried again this Sunday on the trainer, this time I made sure to drink a lot since I was wondering if the issue was dehydration. So I drank 2.5 liter of powerbar’s isodrink while riding the 1.5h Fletcher which is not an intense workout. However it felt intense, like SweetSpot rather than Endurance. At night I then got a throbbing headache and felt super wasted today in the morning with headache and nausea.

So what is happening here, why is my power so low but feels so intense and why am I getting totally destroyed? I don’t habe these problems outside at all.
Will I adapt to it? Did you maybe have similar problems?
Any suggestions what I can do about it?
I generally like the idea of indoor-training, but like this it more interferes with my training than it does good.

Thanks a lot for your input!


First do the ramp test. That should set your inside ftp. I can tell you for me there is a 30 watt difference between inside and out.


Eactly :point_up_2:. Your FTP sounds too high. Use plan builder to set up your training schedule which will start you off with a ramp test to determine your FTP. Your inside FTP will likely be different than your outside.

Make sure you have excessive cooling (fan or fans) that are industrial grade. This can make a big differance.

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@Dominik_Hartl What gearing are you using? In my experience, using a “climbing gear” (little chainring up front) with a direct-drive Kickr will increase RPE making workouts very difficult. If you haven’t, load up a workout and experiment with gearing. To keep a straight chainline I use something like 50x17 or 50x15 gearing and have found indoor and outdoor FTP and RPE to be the same on my Kickr 2017 direct-drive. Find gearing that makes the trainer feel like riding outside. There is a reason trainer manufacturers added heavy flywheels to add momentum.

I’m assuming you have PowerMatch enabled, and both power meters paired to TrainerRoad app. What device is running TrainerRoad? Are you pairing via ANT+ or Bluetooth?

One other thing to check, make sure the Wahoo app is not running on your phone. If connecting via Bluetooth, its possible (however unlikely) that the Wahoo app grabbed the trainer and therefore TrainerRoad isn’t controlling.


Thanks for the feedback @middleman21009, @MI-XC and @bbarrera !
I just finished SSBMVI but was riding each training outdoor without issues, I am confident that my outdoor FTP is correct. Surprising that the indoor FTP could be so much lower, I would estimate that it is about 50W. I will do a ramp test to check when I start SSBMVII.

The first time I was riding I was on 34x17 but after reading that this might be the issue I was riding 50x15, that felt a little better but not much.
I am using my Ipad and connect with the trainer and powermeter via bluetooth and powermatch on “automatic”. Is connection via bluetooth worse than via ANT+? Bluetooth on my phone is off.

Do indoor and outdoor FTP come closer with time?
Also, what I was wondering, if the indoor FTP is so much lower, do I still get the same benefits when riding indoor workouts as outside? I would not expect that to be the case, is there literature on that?

My fan is quite strong, where do you put it? I now had the air flow more facing my upper body, is it maybe better to have it facing my legs?


In that case, I would do an advanced spindown or factory spindown or whatever Wahoo calls it.

Bluetooth has been a better connection for me, both on iPhone and MacBook Pro (I have ANT+ dongles for both).

FTP might be too high but 50 watts seems like a lot.

Also, even if the Wahoo is grabbing the control (and powermatch isn’t working), assuming you’re still getting data from the power meter and the PM is correctly calibrated, that still wouldnt’ entirely explain it. But yeah, definitely make sure that whatever device you’re using to record the ride is in fact grabbing from the PM and not from the trainer.

If everything else really is set up correctly, consider whether this is a nutrition issue.

I personally sometimes get this thing called rebound hypoglycemia. In simplest terms, eating food (esp carbs) and exercise both cause a hormonal response that prompts insulin production. If the timing of the eating prior to the exercise is wrong, it can cause a double whammy insulin response that makes you bonk even though you’re plenty fueled: your liver and muscle glycogen are there, but the sugar in the blood stream just got sucked away. So for me, I have to eat either two hours before, or right before getting on the bike. If i split the difference, bad things happen. It feels like: (i) RPE way out of whack vs. power; (ii) heart rate skyrocketing for same power output I could do the day before with no problem; and (iii) dizziness and nausea.

If there is a systematic difference in the way you approach fueling and preparation for outdoor vs. indoor rides, it could make a big difference, and this could happen without you realizing it. For example, for outdoor rides, maybe you mentally schedule them and plan in advance, whereas indoor rides you just try to “squeeze em in.” Maybe time of day is different. Or, maybe your outdoor rides involve a longer warmup as you ride out to the spot where you start your intervals (which would maybe give your blood sugar time to normalize), whereas your indoor rides only have a short one.

Just things to keep in mind. Your habits, and even how you choose whether to ride indoors vs. outdoors, could be introducing a systematic bias here.

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