Artificial heat is the latest craze. From infrared saunas to heated fitness classes, people are paying good money to sweat out their stress, calories, and toxins. Among the biggest health wellness trends, hot yoga especially has become a thing, sparkling the whole industry of moisture-wicking yoga towels and mats designed for sweaty palms and feet.
Despite having gained momentum years ago and attracting tons of followers each year, the mainstream practice also gets lots of bad rap from critics who suggest that it’s just a marketing ploy full of false claims and unsubstantiated benefits to increase sales.
Which left me wondering: with so many fans across the world and positive feedback on forums such as Reddit and Quora, hot yoga can’t be all lies, and the founder must have been on to something, right?
I’ve read more than 40 research studies to learn whether hot yoga can actually deliver what it advertises, whether it’s good for you and what are the risks for exercising in a heated environment. Here’s what I’ve found out.
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Hot yoga, an offshoot of popular Bikram yoga, is now used as an umbrella term to define a yoga class practiced in a heated room with high humidity. Founded in the 1970s by a notorious yoga guru Bikram Choudhury, hot yoga was supposed to imitate the climate of his home town Kolkata, India. Choudhury heated his rooms to 105° F and kept them at a 40% humidity, an environment which caused your body to sweat profusely and as, claimed by the creator, cleanse and detoxify itself to maintain ‘optimum health and maximum function.’
Traditional Bikram studios still transform their rooms into “Torture Chambers,” as Choudhury called them, by keeping the heating at scorching 105° F, whereas other newly emerging styles of yoga such as Baron Baptiste Vinyasa or Moksha yoga vary their temperature between 85 to 100° F.
Proponents of Bikram and hot yoga swear by its numerous positive effects on physical and mental health. When asked about the reasons for doing hot yoga, people report not only the obvious benefits that can be gained from a traditional non-heated practice such as improved stamina and increased flexibility but also mention better mood, faster weight loss, clearer skin, and detoxification.
When comparing Bikram to a usual unheated yoga, the official website suggests that hot yoga keeps your body from overheating as opposed to a widespread belief, opens the pores to ease the elimination of toxins, increases heart rate to promote cardiovascular health, and protects the muscles for deeper and more efficient stretching.
Sounds great and alluring. Nonetheless, how many of these benefits are actually true and confirmed by science? It turns out that there is little research into the given practice, despite the hype and popularity, and we don’t really know what hot yoga does for our body and mind as well as whether it’s healthy in the first place.
Yoga is unlikely to be the first choice for people who are trying to lose weight. But when it is, hot yoga often comes first to be advised for a weight management program.
Available studies on Bikram yoga suggest that, if practiced several times a week, it promotes positive changes in musculoskeletal fitness as well as can be considered as an exercise of light-to-moderate intensity. These results are hardly surprising considering the fact that Bikram as well as most other hot yoga styles use the postures from Hatha yoga.
The advocates for hot yoga though state that it is not only the intensity of the postures but the demanding and sweat-inducing environment that will make your body work harder and subsequently lose weight. You don't have to search long to find claims that you’ll be able to lose up to 1000 calories per hot yoga session and burn more fat than in a non-heated class.
Undoubtedly, any physical exercise will help you wear off those nasty calories. But there is no evidence to confirm that we can burn more calories just by raising the temperature of the room. Take this 2014 study, for example. Trying to examine the metabolic rate during the session of Bikram yoga, researchers revealed that during the 90 minutes of the workout, men burn an average of 460 calories (way far off the claimed 1000 calories!), and it is even lower for women – 330 per session.
If that’s what your body needs, several sessions of Bikram per week providing your diet is in check may help you lose weight. But the rule for weight loss is the same as always: create a calorie deficit, i.e. consume fewer calories than you expend.
So hot yoga alone won't get you a beach body, but it must be good for the heart, right? If you've ever taken a class in a super hot room or climate, you must know the feeling when you’re sweating and panting, and your heart is jumping out of the chest.
I hate to break it to you, but the American Council on Exercise found in their research that you might be imagining things. They invited 20 female volunteers to attend two 60-minute yoga sessions led by the same instructor. The volunteers participated in a traditional non-heated yoga session, and 24 hours later, a hot yoga session in a room heated to 92º F with significantly higher humidity. When asked to rate the classes according to the level of difficulty, a hot yoga class was ranked as more challenging, and the volunteers reported the feeling of working harder than in a thermo-neutral yoga session.
Surprisingly, when researchers compared the heart rate of the participants during and after two yoga classes, they found no significant difference between the hot yoga class and the non-heated one.
If there's any cardiovascular benefit from this sweaty workout, the heat hardly seems to be the contributing factor, according to a recent study. This 2018 research examined whether the heated environment helps to prevent endothelial dysfunction, a condition that results in a range of cardiovascular diseases. Fifty-two sedentary but healthy adults were randomly assigned to practice Bikram yoga at a regular temperature of 73º F, in a room heated to 105º F or to a time control group. Researchers found that doing yoga for 12 weeks caused positive cardiovascular changes in healthy sedentary adults (as compared to no exercise at all), though we have to thank the yoga postures for that. The hot environment didn't make the practice more beneficial for heart health.
There isn't much truth in the dubious claim that our body gets rid of the toxins by twisting and sweating. Sweat is mostly a mix of water and minerals. Even though there are traces of toxins in it, their amount is so low that it is basically meaningless to our health.
Our kidneys and liver have an effective system in place to process, filter and eliminate toxins. Hot room or a 'gentle massage' for your liver through yoga exercise probably won’t make them work more efficiently.
This, unfortunately, means that hot yoga is unlikely to help you feel better after a night of partying and, on the contrary, might make you get worse and dehydrated. The only way hot yoga (or any other yoga) can help you flush out toxins is by forcing you to drink more water and other fluids.
One of the most plausible and popular claims about the benefits of hot yoga is that the heated environment promotes flexibility and makes stretching safer and more efficient. The hot yoga enthusiasts largely confirm the advantages of the heated room, stating that they feel warm and loose and can go deeper into the pose than in a usual yoga class.
Science confirms that yoga, in general, improves flexibility and range of motion. However, the question of whether hot yoga is more beneficial in this regard remains unanswered.
What we know is that adding heat to the workout increases our blood circulation if compared to the same exercise in the unheated conditions. The high temperature of the air allows us to slack off during the usual warm up because our muscles are getting an additional boost of heat externally. While stretching might feel pleasant and more relaxed in the heat, the lack of effort is not necessarily a good thing.
Which takes us to the next point.
Just like any physical activity, yoga comes with some potential risks. Hot yoga, in its turn, must be approached even more cautiously than a regular yoga class because of its heated environment, which can bring more harm than benefit to some people.
Your muscles might appreciate high temperatures of hot yoga, which can’t be said about the tendons and ligaments that protect your joints. Usually, these joint stabilizers do not get much blood flow but get an extra warm-up thanks to the heat. High temperature also numbs the feeling of pain or severe pressure, letting your body stretch like never before. This is why you might feel more limber and pliable in a hot yoga setting compared to a yoga class with a regular temperature.
If you practice too aggressively, overexert yourself and listen to your ego, it is easy to push past your usual range of motion, and this is a direct path to injury. Those who are highly flexible by nature are at a higher risk, so in a hot yoga room, natural stiffness and lack of flexibility can actually be a good thing.
The most important thing you can do to minimize the risk of any injury is to listen to your body. Only you know how far your body can go. Forget your competitiveness, breathe and try as hard as possible to stay present on your mat and in control of your movements.
Yoga is never about bending more, but it is always about balance and mindfulness.
Sweat is our bodily response to a hot and humid environment. It is supposed to cool us down. But when you’re in a 105º F room with 40% of relative humidity, the sweat just doesn’t evaporate as quickly as it has to, and you sweat more and more and eventually, become drenched. This is when the risk of heat exhaustion and dehydration comes in, especially if you haven’t drunk enough fluids before and during the class.
When the American Association on Exercise measured the core temperature of yogis during a 90-minute traditional heated Bikram class, they found that a large number of participants had a core temperature of 103° F, and one man even exceeded 104.1° F – the score that poses a high risk for heat-related illnesses.
While extreme accidents that result in heat stroke are not very frequent, the symptoms that go hand in hand with dehydration and overheating are often reported by every second hot yogi. Dizziness, nausea, cramping, light-headedness and other similar adverse effects are often experienced by both newcomers and experienced hot yoga practitioners and should never be ignored. Your body hasn’t ‘begun to cleanse itself’ but instead might be giving you a warning sign to back out, take a relaxing resting posture or leave the heated room for a moment.
Hot yoga can be quite safe for healthy people who know what to expect from a hot yoga class, how to listen to their body’s signals as well as adequately prepare and hydrate themselves before during and after the yoga session. However, certain groups of people are at a higher risk of hypothermia and other dangers associated with the heated practice and should consult a doctor before starting any exercise in a heated and humid environment. These include pregnant women (especially those with no hot yoga experience), people with any cardiovascular issues, high or low blood pressure as well as those suffering from diabetes.
Attending a hot yoga class with a common cold is also not a good idea. A hot, humid room creates perfect conditions for spreading the bacteria to your classmates and instructor.
The answer is, not necessarily. After all, hot yoga derives lots of benefits from regular unheated yoga. Besides, due to lack of research, we still don’t know for sure about the effects of high temperatures of the hot yoga practice.
That said, there is a growing body of evidence that artificially exposing our body to heat, aka ‘hyperthermic conditioning,’ might actually be good for health and athletic performance. All of the studies so far focus on sauna bathing and not on exercising in a hot yoga room, but there is a reason to assume that the following processes may take place during a hot yoga class as well. Researchers so far conclude that heat might positively affect the following physical and mental aspects:
On a physiological level, when your core temperature goes up, plasma volume and blood flow to the heart tend to increase. This means that your heart rate lowers and the hearts works less hard, decreasing the cardiovascular strain and improving endurance.
The study on the effect of sauna on the runners’ endurance performance showed that 3 weeks of sauna bathing after the exercise increased athletes’ run time to exhaustion by 32%, which was highly correlated with the higher blood volume. Though the sample size is very small, several other studies support given findings. Like this research, for example.
Protein is the building block of muscles. Our body is continuously producing (muscle protein synthesis) and losing (muscle protein breakdown) protein. The ratio between the first and the latter determines whether we’re building muscles or losing them. Several studies, like this one, show that heat induces molecules called heat shock proteins (HSPs) that help reverse protein degradation and positively affect protein synthesis, thus helping us gain muscle mass.
Many report feeling happy, rejuvenated and ‘high’ after a hot yoga class. While we still don’t know why it happens, heat might actually have something to do with it.
Anecdotally, I’d assume that people welcome the challenge of the hot room and feel like they’ve accomplished more when they’ve survived the practice in extreme conditions rather than a typical yoga class. That’s why people strive to stretch towards splits, run marathons and get 'addicted' to weightlifting.
From a biological point of view, heat stress triggers short-term hormonal changes, particularly the increase in beta-endorphin. The more intense the stressor (the workout, environment, etc.), the better we feel afterward.
Yoga purists might scoff and frown, insisting that you should generate heat from within by applying effort. But some people simply like to stay warm and break a sweat during the yoga practice. Moreover, working out in a hot room during the harsh winter has a wonderfully relaxing effect. If you are one of these people or if hot yoga is the only form of exercise you’re willing to commit to, here’s what you need to know for safe and comfortable practice.
Hydration is key. Drink plenty of fluids the day before the class and do not limit yourself to water. When sweating, we lose lots of minerals such as sodium, chloride, magnesium, etc. that cannot be replenished just by drinking regular water. Try to get electrolytes: Gatorade or coconut water is a good choice. Take time to hydrate during the hot yoga session as well as after it.
Arrive early. Organize your time to come to class 10 or even 15 minutes before the start. It is always a good idea just to lie down and let your body get used to the temperature and humidity as well as work on your breathing.
Stay present. It will be dang hard at first, but try to breathe and stay aware of your body and how it feels. Yoga is all about the process, not the progress. If you’re new to hot yoga, do not strain yourself. On the contrary, use not more than 40% of your body power even though you can sink deeper and hold the poses longer. In case you feel unwell, don’t try to get over it. Instead, take a break in a Child’s Pose or leave the heated room for a while until you feel better.
Looks matter. Well, not exactly the looks, but what you’re wearing to the class. Choose moisture-wicking and breathable yoga pants and top. Avoid cotton and cotton fabrics that breathe but will get heavy and pull you down to the ground when wet.
Prevent injury. Even if you're not usually sweating a puddle during the exercise, in hot yoga, you probably will. Invest in a good hot yoga mat or hot yoga towel to keep yourself dry and safe on a slippery surface.
Have you ever tried hot yoga?
Share your experience in the comments below!