Updated: Jul 30, 2020
Temperatures are on the rise in yoga studios across the globe. Hot yoga was previously an option for those wanting to sweat it out from time to time, but has now taken over the schedules at many studio locations. It's getting harder to find room temperature yoga classes no matter where you go. But what is it about hot yoga that makes it so attractive?
People claim hot yoga has detoxifying properties which promotes overall health and well-being. While no studies have shown any detoxification with hot yoga, some studies have corroborated these claims showing improvements in cholesterol, glucose levels, flexibility, and quality of life. The question is: are these health benefits limited to hot yoga or are other styles of yoga just as effective?
Our research team attempted to tease this out in a study now published in Experimental Physiology comparing changes in blood vessel health and other indicators of heart disease risk after 12 weeks of heated (105 degrees Fahrenheit) or room temperature yoga classes. Our results showed that the brachial (upper arm) arteries dilated more in response to blood flow, which is indicative of the health of the vessel and the risk of heart disease risk, after both yoga programs. We also found that the benefits were the same regardless of the temperature of the classes (105 versus 73 degrees).
I admit: we were surprised! These results weren't in line with our hypothesis as we thought the hot yoga would be more beneficial than the room temperature yoga. The reason for this was that exposure of the body to a heat causes the heart rate to increase which also increases the amount of blood circulating throughout the body each minute. In fact, the heart responds to heated environments much like is responds to walking on a treadmill. We thought if the body is exercising in the heat that the two would act together to produce more beneficial blood vessel changes. We were wrong and this was the first study of its kind which is likely why is generated so much interest.
Our study was covered by over 90 news outlets including Reuters, U.S. News & World Report, Forbes, Time, Refinery29, TODAY, The Times, and many others. People came to many different conclusions with some taking these results as a basis for doing away with hot yoga altogether. I even received angry emails from a disgruntled reader but, the headline I most remember was "If you hate hot yoga, this study's for you." Just to clarify, I'm a big fan of hot yoga and have practiced myself for over 10 years. I enjoy the mental and physical challenge of enduring 105-degree conditions for 60- or 90-minute periods. I also enjoy the feeling of accomplishment once the class is done. This might be reason enough for some people even if they aren't getting much more out of it.
So why practice yoga in a sauna-like environment if you can get the same benefits doing it at room temperature? Right now, the answer isn't clear. There aren't enough studies directly comparing hot yoga to other styles. Some might say you burn more calories in the heat. A recent study looked into this comparing 20 minutes hot yoga (95 degrees Fahrenheit) to a standard temperature yoga session and found that participants in both groups burned about 5 calories per minute. What was affected by the heat, however, was heart rate as it was significantly higher in the group practicing in heated conditions. The same is typically true in comparing other exercise modes in the heat versus temperate conditions: heart rate is higher but caloric expenditure is the same.
Hot yoga does have several documented benefits but yoga in room temperature conditions has produced similar results like improvements in arterial stiffness, blood pressure, stress, anxiety, depression, and quality of life. There could be more health risks in hot yoga than other styles. Exercising in the heat increases the risk of heat illness or stroke. Thus, special consideration should be given when practicing hot yoga as the safety of hot yoga in people at higher risk for heat illnesses like older adults, has not been established.
What we haven't mentioned is the ease of getting into the postures as the muscles could be more pliable and the body more flexible when temperatures are raised. Whatever your preferred yoga practice, vinyasa, power, ashtanga, or Bikram, I think our study results are promising and highlight how effective yoga postures are alone in improving health. While hot yoga is becoming more widespread and room temperature classes are harder to find, the heat may not be necessary to enjoy the beneficial effects of yoga. If you're going to practice hot yoga, just do so with caution ensuring proper hydration (and an empty stomach) before sweating it out on your mats.