We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question!

AASQ #44: Should you use a fan while on the trainer for the best results?

The Headwind needs about three feet of space in front of your trainer for proper placement on the floor. Or, use the adjustable feet to place it on a flat surface in front of you like a table or shelf.

Of all the products we’ve gotten in for review over the years, a heart rate-controlled fan is not something I would have ever expected. But not surprisingly, the Wahoo KICKR Headwind is pretty awesome – but its first few uses got me thinking. It seemed that after a hard workout, I seemed to be sweating less when the fan was on heart rate-control rather than speed, even though I was doing a harder workout – which begs the question, “am I getting less of a workout, or just sweating less?”

AASQ #44: Should you use a fan while on the trainer for the best results?

Once the fan is connected to a heart rate monitor or speed sensor, the LED indicator will go solid. It blinks as it’s trying to connect.

Basically, in addition to the standard low, medium, high, and turbo settings, you can also use the fan’s ANT+ connection to pair with a speed sensor or heart rate monitor. When paired with the speed sensor, it simulates the wind speed based on your pedaling speed, but it only works when you’re pedaling – not if you’re in a super tuck coasting down a mountain in Zwift. On heart rate control, the Headwind speeds up along with your heart rate. This seems to be the most effective setting in terms of cooling and keeping yourself comfortable, but it also seems to lead to less sweating.

That led me to wonder if it was actually better to not have such an efficient fan. If you’re not sweating as much, are you getting as good of a workout? Most of us aren’t riding the trainer for fun, so if you’re trying to maximize your time on the trainer, this seemed like a question worth answering from someone much smarter in terms of exercise science than myself.

To get the answer, I asked Wahoo if they knew anyone that would be the right person to ask, and they directed me to Taylor Thomas, the Founder and a coach at Thomas Endurance Coaching. My main questions were, “is it better to be hotter during a workout? And how does a fan affect how hard your body is actually working?” Taylor’s answer is below:

Taylor: Below are a few key points/takeaways related to the role of heat in training. A fan during indoor efforts would be the key component that would dramatically reduce/limit these negatives, as there’s no evaporative cooling from the wind on a stationary trainer.  

– Elevated temperatures cause an increase in an athlete’s heart rate, reduce blood flow, increase sweat rate, reduce O2 availability, as well as produce a heightened RPE (Rate of Perceived Exertion).

– Increased fluid loss (Sweat) from high heat, can have severe impacts on performance. With as little as a 2% decrease in overall body weight from fluid loss, a 4-6% decrease in performance can be experienced. 

– Temperatures between 60-75° F can see an increase in as much as 2-4 BPM, and 75-90° F can see upwards of 10 BPM. This has a dramatic impact on both RPE, as well as the body’s ability to perform at its peak.

– When you sweat your blood volume decreases, less blood returns to your heart, less oxygen-rich blood reaches your working muscles, and you produce less energy aerobically. As it gets hotter this effect is exaggerated because the greater the amount of heat that needs to be dissipated, the greater the proportion of blood diverted to the skin. When oxygen is redirected via blood flow to your skin instead of your muscles, you have less energy to use for exercise, and your heart and lungs must work harder to compensate for the loss in oxygen.  

All of these issues can be mitigated by using a fan during indoor training. That helps not only keep the room cooler, but also helps to control sweat rate and body temperature. 

To touch on your specific questions, heat is not a tool that helps makes workouts or training better. In my research or experience there’s no greater fat oxidation, or efficiency gains due to the heat. In most cases it only serves to negatively impact training in some way. 

AASQ #44: Should you use a fan while on the trainer for the best results?

Small, but incredibly powerful.

AASQ #44: Should you use a fan while on the trainer for the best results?

No ANT+ devices to connect to? You can manually set it to one of four speeds as well.

Based on Taylor’s response, and the fact that the KICKR Headwind seems to work so well to keep me more comfortable on the trainer, it’s a safe bet that the Headwind will have a permanent home in front of my trainer. Do you need a $250 smart fan to cool you down during your workouts? Absolutely not. But the innovative control features, compact size, and impressive amount of airflow make it very desirable. It really does cool you better than your average fan, and does so in a way that is based on your physical exertion. At this point, I haven’t tried anything else like it. The only caveat so far has been a slight clicking noise at slow speeds that was just loud enough to be annoying. Wahoo swapped out the fans, and the new version is silent. So there might be a few bugs in the first batch, but like all of their products, Wahoo stands behind it.

wahoofitness.com

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16 comments

  1. TheKaiser on

    The fan seems like a cool idea (no pun intended) for someone who wants a totally decked out indoor training setup.

    Having said that, first of all, why would you choose an “expert” to consult via a recommendation from the fan manufacturer?

    Second of all, Thomas is clearly either hoping to help sell fans with his info, or he is just poorly informed. Sure, staying cool while riding will improve your performance…in that particular workout. If you are actually training not to “win” that particular workout, but instead to spur adaptations that will enhance future performances, then heat exposure has substantial benefits. There is a ton of research on the topic, but for an overview just search for the Outside Magazine article entitled “The Surprising Benefits of Training in the Heat”.

    Then, turn the fan down and let yourself be uncomfortable, red faced, sweaty, and maybe even a little sick feeling. Your future self will thank you for it.

    Reply
    • Paul S on

      I took a quick look at the article you mentioned, and my takeaway was that it may be beneficial, but only safe under the eye of an exercise physiologist. Better just to use the fan, even if you decide to do it in a warmer room

      One of many informative quotes:
      “But successful heat adaptation is difficult—and clearly dangerous—to achieve outside of controlled settings. Lorenzo explains that performance gains are possible only when athletes elevate their core body temperature, and without careful monitoring, it’s possible to elevate your core temperature to lethal levels.”

      Reply
  2. Dinger on

    ” but it also seems to lead to less sweating.”

    The airflow doesn’t necessarily lead to “less sweating”. It does lead to more evaporation. This is why you seem to stay dry, the sweat is evaporating as you secrete it, like it’s supposed to (evaporative cooling..).

    The best example I can think of is the way you are almost immediately drenched with sweat when you stop on a hot day. You didn’t just begin sweating, it just isn’t evaporating when you take away the airflow that moving at speed provides.

    Reply
  3. AK_Ben on

    Um, I just assumed everybody would use a fan so that they would benefit from the cooling effect and not be in a pool of sweat while on the trainer. Why the hell would anyone feel like they needed a fan linked to their HR via Bluetooth? I have a Vornado, 3 speeds, $45. I’m going to guess that no pro cyclist would think “wow, this will really make a difference with my training”. This is aimed directly at MAMILs with more money than sense.

    Reply
  4. Matthias on

    No fan keeps the room cool. To be pedantic about it, they *warm* the room because the electric energy that goes into them is converted into heat. Although that should be a non-issue anyway because either
    – it’s too cold to ride, so you can just turn down the heating
    – it’s too hot to ride, so you’re likely in a place where you have aircon anyway
    – it’s neither too hot nor too cold so GTFO and ride

    Reply
  5. Chader on

    Plenty of info out there. 1 basic scenarios.

    1. If you want to maximize performance I doors, you need LOTS of airflow to provide for evaporation and the associated cooling. Failure to cool leads to rises in body temp and eventual limits in performance. If you wan to gain, control the heat.

    2. If you are aiming to prepare for a hot and/or humid race and want to prevent poor performance in that event, you can use heat acclimation training. Low intensity rides done several times a week, 2 weeks before the event can lead to notable increase in performance vs not heat training.

    TrainerRoad has covered this all well in their podcast and blog.

    Reply
  6. i on

    This has got to be the stupidest question yet. And the stupidest, needlessly lengthy answer that sounds like nothing but advertising.

    Other than a high school wrestling coach from the 50s, does anyone honestly think that working out = sweating? By that logic, why not set up your trainer in a sauna? Do you not have access to a hrm and power meter on that fancy trainer? Looking at those numbers for 10-15 minutes would easily show that your power/hr and power/rpe are lower when it’s hot. Unless you’re the kind of rider that has a bunch of expensive gizmos but has no idea what the numbers mean.

    Reply
  7. JBikes on

    Who chooses to ride into a headwind? I setup all my fans for tailwind and achieve 45.2% higher VO2 max and can consume all the lactates.

    Reply
    • Robin on

      That’s a smart move. I hope you sit up to maximize the aero benefit. Me? I bought a fairing and some of those slick aero “fenders” and spoke thingees that BR wrote about a few weeks ago to reduce aero drag from the fan. My drag numbers are really low now on the trainer.

      Reply
  8. carlos on

    Gotta wonder at the competence and objectivity of anyone who quotes that 2% weight loss bunkum. It’s been thoroughly disproved and is not relevant for anyone with reasonable fitness.

    Reply
  9. AngryBikeWrench on

    Surprised nobody has pointed out the catastrophic effects of sweat dripping on your bike. Nastiest bikes I’ve ever worked on were trainer bikes, and their owners were shelling out a lot of money to keep them safe and functional.

    Reply
  10. Eli on

    Getting Wahoo to comment on if the Wahoo product is worth getting is very very biased. It may be a great product and may be worth getting but the way you’re presenting someone with a clear bias makes it seem like it must not be that good if you can’t get a third party to say its a good product.

    Next you’ll have a question if supplements are useful and you’ll get a supplement maker to give the answer?

    Reply

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