I like a hot Bikram Yoga class — the feel of the sweat on your skin, your pores opening to let out the toxins (kind of), and your muscles stretching farther than they would normally go. But the humidity – you can keep it. Maybe it is the changing of the seasons, but class has felt incredibly humid lately. This is good news for the overzealous ladies who set up in the hottest corner of the room and blast the humidifiers into their face throughout class, but not for me. I like a more modestly humid class, so I can focus on the postures and my meditation instead of simply trying to breathe.

The temperature in class, or anywhere, really, is dependent on two things — the air temperature and the relative humidity. Scientists combine the two into a heat index which attempts to express how the “real” temperature is perceived by people. For example, according to Wikipedia, when the temperature is 90°F with very high humidity, the heat index can be about 106°F. In a Bikram Yoga class heated to 104°F and 40% humidity, it can feel like 119°F, but at 55% humidity, it can feel like 137°F.

Humidity can also make it harder to breathe. As explained above, a high humidity class just feels hotter, probably because the body’s natural cooling mechanism of evaporating sweat does not work as well when the air is already saturated with moisture. This causes your body temperature to rise. If your body temperature gets hot enough, your body goes into survival mode, concentrating blood flow to vital organs like the heart, which may start pumping at a higher rate. This can lead to a feeling of shortness of breath.

On top of this, if my heart starts racing, I begin to panic, which is not conducive to the whole breathing in and out calmly through your nose situation I strive for in class. If class is super humid, I will often feel the need to sit out a posture or two, but depending on the levels of humidity, my body may not recover quickly, leaving me down for the count for much of the remainder of class. I am usually not alone.

Last week, I even walked out of the room for a few postures! I had not done that since the very early days of my practice 6 years ago. Perhaps I was just having a very bad day, but maybe the new plastic covers on the windows (installed each year to insulate the room for winter) are making climate control a bit more challenging for the teachers. I hope things will return to normal soon.

Fellow yogis, does the humidity level in class impact your practice?

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