Although you benefit from the lower humidity, and temperature, aiding your sweat evaporation I think you still could improve the situation by introducing air flow with a fan or three.

To add to the chorus…

I started without a fan. I was soaked, the towel beneath me got soaked, the bike top tube got soaked - it was not fun. And this is probably in a room of c. 20 deg C.

We have an outside powerpoint, so my next step was to rig the trainer up outside. Cool day (about 15 deg C), light breeze - pretty much the same result.

I got a fan. Then I got another.

Much more pleasant and my power output got much closer to my outside numbers.


I also started without a fan, because who need a fan? And everything was awesome, no sweat at all (I sweat very little). But then combination of FTP going up and longer intervals and I was cooking inside. Bought my first fan. And then my FTP went up and I have started doing thereshold workouts like 3x20 or longer. Boughr another fan. My FTP went up…you know what? Bought third fan and dehumidifier. I train in 30m^2 room and even doing Z2 workout rises the temperature by 2°C and humidity 5-6% (closed window). When the window is open the only difference is less humidity hence less sweat but not having a fan? Too hardcore for my taste.

And friend of mine have just bought a trainer. He rides in a cool basement (15°C) with open window. Of course he told me he does not need a fan, because he does not want to spend any money. 3 rides later - he is buying his first fan. The conclusion is that no one can make you to buy a fan. But in the end you should buy three of them and be able to train as a decent human beeing not a frog that is slowly cooking.


You absolutely do need a fan.

My tip: Get a smart plug(s). I have a no name one for 10ish $. Works like a charm when I tell google after my warmup turn on the fan. Can also be just turned on via phone.


Smart plugs are definitely the way to go. You can have multiple fans individually voice-controlled so you can regulate all the way through a workout depending on intensity.

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Thanks Chad. Looks like i’m going to buy another fan…

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I’ve ridden up a ski hill at 0F in short sleeves on a fat bike. No wind. Riding at 3 mph. Sweating.

Airflow is key.

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Some great discussion on cooling & airflow, starting at 18:20.

  • One fan is almost never enough.
  • Pool of sweat on the floor = bad and insufficient cooling
  • Use several fans (3 is mentioned).
  • Back, Head & Torso = all-around airflow

Good to hear this getting more coverage and traction in wider reach.
Proper cooling is essential for training, with the notable exception of deliberate heat training.

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I started with open window some years ago. Since I have a van, I never would ride indoor without again. It is not only about the temperature but as well the chill factor, which I don’t like to miss again.

My first indoor session was in a gym. The Gym was cool (about 10C) and I ended with a pool of sweat on the floor.

Now I train with a powerful blower fan pointed to my chest and a circular fan close to my face, also with a towel near to wipe out sweat during recoveries. I don’t end with a pool of sweat under my bike anymore. Gym bikes are useless due to lack of proper cooling.


I did that once - an hour’s Sufferfest workout with my phone taped to the screen on a gym bike with no airflow. I looked like i’d had a bucket of water thrown over me by the end.

I got some horrified looks from the “normal” gym goers :rofl:


I’m in a similar climate- mountainous, gets to ~-30c pretty frequently, big window. I did my first winter on TR with no fan, just opened the window 30min or so before my workout and let the room get really cold.

The room felt like a sauna by the time I was done- and I’m a 110lb female so I generate substantially less heat/sweat than most. I did manage to complete most of my workouts, but looking back the quality has improved noticeably since then. I’m hitting my targets more consistently with less instances of modifying the sessions through dropping intensity/shortening intervals/whatever. I also wouldn’t underestimate having a lower RPE- indoor training isn’t “fun” at the best of times, so if you’re going to be putting in the work and hammering it over the winter, I think it’s worth fronting a relatively small amount of money to make sure you get the most out of it.


When I got a trainer I set it up in my shed, and popped my fancy bladeless Dyson fan in front of it, next to the window, which I opened to get nice, cool, fresh air blowing in from outside. It took me around 6 months to realise the Dyson pulls air from 360 degrees around the base before channelling it through the head, and as such the open window had little to no effect :man_facepalming:t2: Nice placebo while it lasted!

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Both, and either/or.

When it’s cold in the 30s/40s F, I do use an open door as a fan gets too cold with the fan. If I do use a fan, it’s more for circulation than blowing directly on me, as it would in warmer temps. An open garage door with a fan to swirl the air in 30-40F gets darn cold, and just a small movement of air really cools quickly.

In warmer temps, I have a fan blowing directly on me, maybe not all of them until it gets even warmer.

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End thread


Thanks for the follow up info. It is really eye opening when you get a proper fan (or two… or three :stuck_out_tongue: ) to get actual cooling while inside. Moving as much air as possible inside is king, even if you have cool ambient temps.

Happy (cooled) training :smiley:

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You will still need a fan, I train in a cold basement and in the winter and I still need a fan on high and on occasion have I needed 2. without them you will become VERY warm on any workout of consequence and quality will suffer

Yup, he just acknowledged it today. (scroll up a few posts)

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