Is hot yoga dangerous to your health?
By Stacey Gretka

According to many studies conducted over the last few years, yoga is not only a fast-growing trend in the workout world, but boasts many positive outcomes for its participants. The list of benefits to yoga lovers includes "lower perceived stress levels, improved cardio-respiratory endurance and improved balance (Hewett et al., 2001), as well as increased dead lift strength and shoulder flexibility, and modestly decreased body-fat percentages (Tracy and Hart, 2013). In addition, Hunter and colleagues (2013) found that Bikram yoga improved overall glucose tolerance and insulin resistance in older adults who were at high risk of developing metabolic disease." There is no question that performing yoga can result in a healthier life for most. And yet the question remains: is hot yoga dangerous?

The question stems mainly from the hot yoga practices, like Bikram, that rely on intense heat and humidity, lengthy class times, and restricted water intake. Since we know that core body temperatures above 104 degrees Fahrenheit result in a higher risk for heat-related illness, the real question is are you putting yourself at risk for heat stroke or heat exhaustion when you take a hot yoga class?

The answer: yes. 

A study published this year in The Gunderson Medical Journal reviews the core body temperatures, heart rates, and more of participants (of both genders) of hot yoga classes. And the results were of concern: participants' core body temperatures continued to rise, no matter the difficulty of the poses, and no amount of sweating was able to bring their temperatures down. Furthermore, their heart rates increased, again in relation to the time not the difficulty, despite little to no movement which suggests the heart was under duress in its attempt to cool the body. The good news: none of the study's participants exhibited signs or symptoms of heat-related illness, even though one participant's core body temperature did exceed 104 degrees. Keep in mind that it's well-known that exercising during extreme heat is risky and yoga is not an exception to this rule.

The main take-home message was simple:

1. Keep class times below 90 minutes, preferably closer to 60 minutes. 
2. Stay hydrated.
3. Know the signs and symptoms of heat-related illness and leave the room if you begin to experience them.