updated March 24th, 2017
Why use a fan?
If your goal is to improve your cycling performance through indoor cycling then cooler is better. Simply put, dissipating heat through the use of fans and a cool room will allow a higher output during tough sessions, which means you get the stimulus needed to improve
When to NOT use a fan:
However, if your goal is to shed water weight and sweat so much that the mop comes out post-class, then you should forego the fans and cooling and come outfitted in sweats and an impermeable plastic suit. We think most of our regulars have the former goal. Perhaps it’s a lingering vestige of the fitness industry that causes many to believe that more is better when it comes to sweating. Let’s examine the issue further.
The Role of Heat Waste:
Every time you get on the bike some of your energy is lost to heat waste. Your body works harder to cool itself. That’s energy you cannot use to put out more power. When we talk about efficiency in cycling, we’re referring to the amount of effort you’re putting out that actually translates into pushing the pedals. Estimates of average efficiency vary, but let’s assume that you’re at 20%. This means that for every 10 watts you see displayed on your head unit, 40 more are lost to heat waste. So you simply won’t be able to perform as well if you’re not making an effort to dissipate that heat (through cooling down the room or the liberal use of fans)
In addition, we have to pay more attention to the role of heat waste in indoor cycling, as outdoors we have our very own convection system on full blast. Outdoors the wind that blows over you as you pedal down the road helps dissipate heat waste due to forced convection.
But, you may say, if my race is in the heat and humidity surely I can improve my performance by simulating those conditions indoors? Yes, but doing all your training in the heat of the day will leave you dehydrated worn out and with a lack of opportunity to perform at your max. A better compromise would be to perform some of your easier sessions during the heat and save your hard interval or key sessions for either indoors with proper cooling and ventilation or outdoors when the weather isn’t as brutal.