“Why do you keep it so COLD in here?!”
At my studio, we keep things pretty cold. Anywhere from 64 to 68*F throughout the year. You’d likely wonder what’s the point, as most places seem to be encouraging more heat: hot room yoga, Xfit boxes with the bay doors open in summer, boot camps in the screaming summer sun, etc. It’s rather different compared to these other places, so what’s the deal?
During my first certification and job, it was basically “People work harder in the cold.” That was the answer I got, and while true, it didn’t tell me why they were able to work harder in the cold. It was sort of a “handed down from on high” commandment; I wanted the science. And during graduate school I found it.
While probably not the first researcher to study this, the man whose research work is most focused on exercise and environment is Lars Nybo. His research has dealt with how hyperthermia (exceedingly warm conditions in the human body) changes muscle function, brain function, and human performance. I’m going to discuss a little slice of his research and then provide the bigger picture for EE clients.
In his study, “Hyperthermia and central fatigue during prolonged exercise in humans” Nybo demonstrates how hyperthermia changes force output, regardless of fatigue. Two groups of trainees cycled for 1 hour in either a thermoneutral environment, or a hyperthermic environment. After 1 hour of exercise, the trainees were then put on a knee extension machine and encouraged to exert as hard as possible to measure the force output of the thigh musculature. Take a look at the result:
So what the heck are you looking at? The top graph (“A”) shows the rate of force output decline difference between the hyperthermic group and the thermoneutral (control) group. Also in that graph, you can see lines that spike up from the trending measure line, which is where the researchers actually electronically stimulated the tissue to measure it’s true maximum force output. Remember: muscle force is not just what the tissue can actually produce, but also what the central nervous system will allow or is capable of at the moment. You can see this difference in graph B, where the hyperthermic group is significantly less forceful compared to the control, as far as a percentage of what the tissue is capable of producing. Finally, the third graph (“C”) shows the surface measure of muscle activation; again, a clear reduction, thus reduced force.
So what this shows is that the hotter the environment is, the less forceful the muscular contractions are, NOT because the tissue is less capable but because the central nervous system is reducing force output or work. This makes sense: the harder (or more) the work, the more heat produced. The already hyperthermic environment means that hyperthermia is a very real threat, so your body “turns down the volume” to keep that from happening.
In the context of training, there are a LOT of variables that are trying to be optimized during a session. If you’re going to only train once or twice per week in a “formal” fashion, the environment needs to be optimized as best as possible for the task. By keeping the room cool, not only are we able to appeal to those who don’t like sweating, we’re also able to facilitate harder work. This deeper stimulus is what allows us to have less frequent workouts with the same, or better, result. It’s not arbitrary: the cold is a big reason why we’re so efficient.
Skyler Tanner is an Efficient Exercise Master Trainer and holds his MS in Exercise Science. He enjoys teaching others about the power of proper exercise and how it positively affects functional mobility and the biomarkers of aging.