SENSIBLE SWEAT™ ~ Redefining Hot Yoga

To educate and empower yoga students about the benefits, truths & myths regarding heated yoga classes.  An interview with Karen Kelly, M.S., PhD, metabolic physiology expert & Sandy Gross, Evolution Yoga studio director.

~ A thesis project by Evolution Yoga Studio director and OM yoga 500 teacher training graduate, Sandy Gross.

Looking for SENSIBLE SWEAT™: Detox Flow Yoga Workshop? February 20, 7-9pm

Physical yoga is a cleansing practice, or “kriya”, in Sanskrit, and an adequate level of internal heat is necessary to create the best conditions for internal cleansing and for stretching your muscles.  However, proper hydration is the key to optimizing the benefits of this process and minimizing any risks.

Modern medicine and Eastern philosophy & science agree:  Cleansing happens inside your body, not through sweat, a common misperception. Only trace elements of toxins are released through sweat.

Yoga (not heat) helps remove the toxins from your body and promotes circulation and vitality.  Breathing deep & yoga practice (not simply heat) increases blood flow to your muscles. Paying attention to what you are feeling and responding appropriately reduces injuries as you become more flexible, not an external source of heat.

Our rooms are heated in between 78–85 degrees, supportively warm (not stifling) to preserve the internal and most authentic, deep heat built during the practice.  We do not add artificial humidity, we work with the natural elements of our 4 seasons and adjust the temperature accordingly.  Our air filtration system is used frequently so that like you, our room can breathe deep & free.

This is NOT about anti-sweat...a sensible sweat is a positive sign that you are *HOT* on the inside and that the body is attempting cool down.

The body is cooling down to protect its' internal systems ~ to find balance ~ by using it's own internal water source -  which comes directly from your bloodstream - to bathe your skin.  As sweat evaporates off the skin, you cool down.

Sweat is vital fluid.

Oversweating is a sign that you have too much internal heat, a sign of your body being out of balance - an extreme condition that not only can be dangerous, but that is simply a waste of your energy and vital watery quality of your blood, lymph, brain fluids & joints.

Hydration is key

Drink up approximately 1–2 hours prior to class (to avoid bathroom breaks during class;), ideally water or any fluid w/o caffeine. We recommend you don't drink water during class in order to preserve the internal fire, or “agni”, nor disturb your focus.

Feel free to bring in an empty water bottle for last minute hydrating or fill it up with our bottled spring water for $1 after class.

Let us know how else we can help you begin or deepen your practice.

Namaste~

*If you are a yoga student, teacher or studio owner and would like to have your name or business name/link added to a growing list of yoga teachers and studios in support of this work, click here to send us an email.  This list will be featured as part of a future non profit web site project featuring Sensible Sweat.

Q & A on Heated Yoga, Sweat, Detoxing & More
An interview with Karen Kelly, M.S., PhD, metabolic physiology expert & Sandy Gross, OM yoga 500 hour teacher training graduate.

Why is vinyasa yoga practiced in a heated room?
Can too much heat be a concern for vinyasa classes?
What is Bikram’s “Hot” yoga?
Will a higher room temperature make me more limber and better able to get into my poses?
Why not have a cooler room than in the 80's?
Will I lose weight if I sweat a lot?
Will a good sweat rid my body of toxins?
I heard that heat and sweating alot in class gives the kidneys a rest. Is this true?
But I like to sweat! What if I just like the heat and I feel OK, is it safe?
What is the optimal temperature for vinyasa classes?
How should I feel during and after practice?
How can I maximize the cleansing or detoxifying effect of my yoga practice?
There was just a study done in Germany last month in the news that said heat helps kill cancer tumors. Does that mean vinyasa or Bikram yoga can help keep cancer away?

Why is vinyasa yoga practiced in a heated room?
Karen: Heat brings blood flow to the muscles and supports the stretching aspect of the practice. We work with internal heat and external heat. External heat from a wall heater is added to support the primary sources of heat happening from the movement of your body and deeper breathing in vinyasa yoga class. Balancing your heat is necessary for supporting thermoregulation, the body’s ability to keep its’ temperature within safe boundaries. This can be challenging in a heated environment.

What is the Heat Index?   The heat index (HI), which was created by a meteorologist and adopted into use by the national Weather Service in 1979, is an index that combines air temperature and relative humidity in an attempt to determine the human-perceived equivalent temperature — how hot it feels, termed the felt air temperature. The human body normally cools itself by perspiration, or sweating, which evaporates and carries heat away from the body. However, when the relative humidity is high, the evaporation rate is reduced, so heat is removed from the body at a lower rate causing it to retain more heat than it would in dry air. Measurements have been taken based on subjective descriptions of how hot subjects feel for a given temperature and humidity, allowing an index to be made which relates one temperature and humidity combination to another at a higher temperature in drier air. The Heat Index figures are based on temperature measurements taken in the shade and not the sun, so extra care must be taken while in the sun.   Heat is the number one weather-related killer in the United States.  The National Weather Service statistical data shows that heat causes more fatalities per year than floods, lightning, tornadoes and hurricanes combined.

*"The heat index figures above are based on temperature measurements taken in the shade and not the sun, so extra care must be taken while in the sun." National Weather Service (click the chart above to read more about the heat index.)

Can too much heat a be concern for vinyasa classes?

Karen: Vinyasa is a flowing practice and sometimes uses vigorous sequences and breath work to generate internal heat, two cornerstones of the vinyasa practice. Internal heat is more authentic and gets right into the muscles and connective tissue far more effectively than external heat, which mostly heats up the skin's surface.  Studios need to also take into consideration, the weather outside. In colder months, it might be helpful to be at a higher room temp, summertime, the lower end. It makes sense to work with the elements of nature. 

Sandy: City governments put out advisories against doing any activity in high temperatures outdoors, why should indoor be any different?  Balancing your heat is important for getting the most out of your practice—from improving flexibility safely and supporting the body’s internal processes for cleansing, detoxing, or as the ancient yogis call it, “kriya”, or purification.  We recommend vinyasa styles maintain temperatures within the range of 78–85 degrees, at the higher end in the winter, at the lower end in summer.  Your age is also a factor.  Twenty somethings can handle more heat than fifty somethings.  Women, also process heat better than most men. 

Most importantly, teachers & studio owners should pay just as much attention to air temperature in their classrooms, humidity, overall air quality and their students responses just as much as they do to sequencing, music & imparting the teachings of yoga.  Teachers should ask themselves, "Can my students pay attention to what they're feeling, and stay focused within the practice, or are they dropping to child's pose because they're too exhausted?"

The trend has been to add more heat, to boost that element of a "workout", some teachers blending yoga styles to create a new style, such as blending vinyasa with Bikram yoga (sometimes called "hot yoga") or vinyasa flow with weights in high temps.   As each yoga community grows, it evolves and at first, gets very influenced by western thinking of "more is better".   The high heated yoga classes are very popular, and there  seems to be little or no questioning of the unsubstantiated claims on web sites or what some yoga teachers are promoting about high heat.  There are no substantiated facts or research on such high heat being beneficial, rather quite the opposite is true, hence why I created this project.  We revisit this "hot" topic often as we plan our class schedule: "Are we meeting peoples needs & requests and yet educating our student population along the way with what facts we do have?"   At the very least, know what you are doing and why you are doing it, going into a heated yoga class educated, rather than simply being a follower of a trend and thinking heat is good for you because someone said so.

What is Bikram’s “Hot” yoga?
Karen: Bikram yoga is a 26 asana series done in a room at 105 degrees. Bikram is considered a static and very therapeutic practice (lots of standing or lying still). It was originally brought to US from India by the American Medical Association for its’ therapeutic benefits, the system designed by an Indian teacher, Bikram Choudhury. There are as many rest periods as there are poses. There is no element of vinyasa or flowing from pose to pose involved at all so it uses external heat to support this very static practice. It is slow, methodical and mindful so that you can truly feel what is happening and respond appropriately. Extreme heat like this can also act as an analgesic, like taking 4 Advils, so mindfulness is super important as the heat goes up in order to prevent over stretching.

Sandy:  Bikram yoga teachers have a history of strongly discouraging drinking water during the practice.   I have heard two trends emerging: some teachers are now encouraging drinking water due to recent news articles reporting deaths during other high heat activities: high school sports practices, marathons and sweat lodge ceremonies. The second trend is alarming: some teachers/studios are taking the heat higher than 105 in cities where there is now increased competitionin their area of copy cat hot yoga classes and the emergence of hot power yoga vinyasa classes. 

Bikram himself has said "My series is for beginners. Westerners are beginners.".   Other Indian teachers offer more advanced practices that include inversions & savasana (which Bikram 26 pose series does not include) .  My teachers and their teachers agree, inversions and savasana are a must for a complete practice, regardless of your level of advancement.  

‎"Penetration of our mind is our goal, but in the beginning to set things in motion, there is no substitute for sweat.”
-B.K.S. Iyengar

In vinyasa practice, first of all, the heat does not need to be even close to 105 because it is a more active, flowing practice.  Traditionally, it is recommended to be hydrated before you get to class and not to drink during class in order to preserve the internal heat you have built from flowing through the sequences of poses and the breath work.  There is no vinyasa nor ujjayi breathing as part of a Bikram class, rather, Bikrams series of postures has a rest time following each pose. Students need to be self aware as to their physical limitations. Anyone on medication or with health problems should consult a physician before they take a Bikram or any extremely heated yoga class. 

 

Will a higher room temperature make me more limber and better able to get into my poses?
Karen: Muscle tissue will soften in heat, moreso with internal heat, less so with external heat. If the external heat is too high in vinyasa class, heat exhaustion is a concern as is over stretching. Ligaments and tendons have much less water content than muscle and are less affected by temperature. Too much heat can have an analgesic effect on the body and can reduce your ability to truly feel what is going on. Often, a false sense of security happens and you can be lured into working beyond your ability and cause tears or strains. Kind of like taking Advil for an injury: you feel better and think your fine and then when it wears off, the pain comes back. In Bikram, the room temp is 105 and each pose is held and monitored closely by you and your teacher for 1 minute each so there is time to monitor what you are feeling. In vinyasa, you need to choose a level and style in which you are able to monitor yourself, in case you get into a class that is above your level. The internal heat you generate in vinyasa class combined with the supporting role of the external heat will make you hot enough for vinyasa class.

Sandy:  Since 2003, we have been hosting many internationally recognized vinyasa yoga teachers at Evolution several times a year and have learned much from them.  They request the room temps to be in the high 70's to low 80's for their classes & workshops...Seane Corn, Bryan Kest, Cyndi Lee, Joe Miller, Simon Park, Desiree Rumbaugh, Kathryn Budig.   The common themes are that they want you to be able to pay attention to what you are feeling, have maximum energy for your practice and to leave class feeling refreshed, or as Kathryn Budig says, "yoga should not send you home to an icepack!".

Why not have a cooler room than in the 80's?  Sandy:  External heat from a heater is helpful when used as a support to your own bodies heat.  In a moderately warm room, low 80's, your body heat can get warmer faster, but authentically, from the inside out.  Muscles can stretch easier, and safer, too.   You sweat a little but you can feel everything that is happening in your body.  Yoga practice is about creating an environment of paying attention to sensation, not shutting off sensation.  We know from the medical use of heat, that heat can also take away sensation or pain.  We don't want to shut down the bodies ability to feel pain in yoga practice.  Notice how much you are sweating. If you are sweating moderately, that is a good level of heat for you.  If you are dripping, not only are you losing vital fluid, but you probably have that numbing effect going on a bit, and could over-stretch and not feel it til later.   It really is a personal experience and you need to find your own comfort level balanced with this information.

Will I lose weight if I sweat a lot?
Karen: When you sweat you will temporarily lose weight—but this weight is just water weight (water and electrolytes) and not fat weight, and you will put it straight back on as your body is re-hydrated. In addition, as little as a 2% loss of body mass from fluid loss will impair exercise performance. This means a 150-pound student who loses roughly 3 pounds during a heated yoga class from excessive sweating can experience increased heart rate and decreased blood volume, causing a loss of strength and endurance.

Will a good sweat rid my body of toxins?
Sandy: Sweat is first and foremost your body’s thermoregulation unit, a means to cool the body down. It essentially will only “cleanse” your skin much in the way a sauna would. “Less than 1% of toxins are lost through sweat” says Dr. Donald Smith, Professor of Environmental toxicology at UC Santa Cruz. Dr. Dee Anna Glaser, professor of dermatology at St. Louis University, and founding member of the International Hyperhidrosis (excessive sweating as a medical condition) Society agrees, “Sweating for the sake of sweating has no benefits and will only release trace amounts of toxins.”

Karen: In yoga, the act of sweating is an indication that heat is being created on the inside—that you are making an effort. Sweating in normal temperatures is a sign that you are challenging yourself. There is little effort required to sweat in a 90+ degree room. Excessive sweating combined with the vinyasa practice actually causes the body’s internal detoxifying organs (kidneys, liver & lymphatic system) to slow down, thus hinder their job to rid the body of toxins.

 

I heard that heat and sweating alot in class gives the kidneys a rest. Is this true?
Karen: No, sweating does not give your kidneys a rest, in fact it makes them work harder. What gives your kidney's a “rest” is maintaining a healthy hydration level, drinking lots of water and not sweating excessively and eating pure foods so there is less junk for the kidneys to filter out of your blood. The kidneys and liver function to clean and purify the blood of impurities and more specifically the kidneys are involved with reabsorption of "precious" items, such as glucose, salts and other trace minerals and water. The more “junk” that is in the blood and gets filtered through the kidneys, the more stress is placed them. In addition, the kidneys regulate blood pressure by monitoring changes in blood volume and secreting hormones to aid in water/fluid retention/excretion thus balance. Excessive sweating can actually be very detrimental to the kidneys. In order to produce sweat you need water and that is taken from the blood stream. Excessive sweating stresses the kidneys out because there is less volume of water in your blood and thus the blood is thicker, and thus harder to filter through the kidneys.

But I like to sweat! What if I just like the heat and I feel OK, is it safe?
Sandy: You will still sweat in vinyasa classes, but it's simply not necessary to sweat alot, hence the name of this site and the goal, Sensible Sweat. Sweating causes the body to lose water. As stated above, if you are only 2% dehydrated, for example, it significantly decreases your exercise performance, increases the feeling of fatigue, contributes to mental “fuzziness” and so on.

Karen: Also, dehydration can lead to damage to the joints over time because the primary type of joints in our body are called synovial joints and they are fluid filled joints, such as the knee, shoulder and hips, etc., and thus they rely on the water in the body to make the synovial fluid.  Dehydration can contribute to elevated blood pressure, kidney damage, not to mention slow down the bodies ability to process and eliminate toxins. Just think that the body is predominantly water, so being depleted will affect function of all the organs, skin & tissues. 

Consider what happened at the Chicago Marathon in 2007. It was October 7, 2007 and what should have been a perfect day for the 30th annual race. But with 88 degree temperatures and humidity to match, organizers were forced to shut the race down in the middle and more than 300 runners required medical attention and one died. Surprised? Marathon runners are among the most physically fit athletes; however, high temperatures and humidity were no match for their training.

What is the optimal temperature for vinyasa classes?

Sandy: While that depends on your physical condition, age, etc., my experience as a student, and a teacher observing thousands of students for over 11 years, vinyasa classes do not need to exceed 80-85 degrees, and the weather & humidity outside being taken into consideration. Sensible sweat is what we are looking for to guage adequate internal heat.  Excessive sweat is just that.  Excessive and not necessary. 

Karen:  I agree. In addition, people with any sort of pre-existing conditions or on certain medications should never engage in activities that stress out the thermoregulatory, cardiovascular and to an extent, the lymphatic system, or if they do so it should be under controlled situations. As with any physical activity, the room temperature should start at a safe and comfortable setting that allows you to generate your own internal heat as you practice.

Sandy: Pattabhi Jois, the father of Ashtanga Yoga where today's vinyasa yoga classes draw their roots, says "with consistent practice, sweating should actually stop".  (He is also quoted as saying, "...external heater, never! Very bad, bad!"  But then again, he has never been to Cleveland in winter!)  What he means is, purification is more of an internal practice, and efficiency with the body’s ability to maintain heat through the poses and breath work is what’s important as is cooling itself. It’s a balance and yoga is about balance. In addition, Jois and other master teachers say it is traditional for the physical practices of yoga in India to be practiced in the early morning in order to avoid the higher temps of the days heat.

How should I feel during and after practice?
Karen & Sandy: You should feel a sense of relaxed wakefulness that permeates your mind and body, not depleted or wiped out. Here’s some tips on how to stay safe & maximize the benefits of your practice:

• Choose the appropriate class level for you as is coming hydrated to class.
• Save additional water consumption for after class so that you maintain your internal heat. It is best to arrive hydrated. (Try setting an alarm on your cell phone to remind you to drink up about an hour before class. )
• Bring a towel to practice to help keep your mat slip free, but know that the sweat that stays on the body helps to cool your body while you are working, so that you can continue to practice at the same intensity. Sweat is meant to evaporate, this is how it cools the body, so refrain from excessive wiping. Constant wiping will only make your body sweat more, and potentially dehydrate you unnecessarily. When sweat is removed from the skin, evaporation will not occur, and heat will be retained. Sweating will subsequently increase, leading to a greater loss of body water and increased dehydration.
• Choose teachers that moderate the air quality and humidity well for the size of the class, more bodies in the room increase the release of moisture into the air. Humidity impairs evaporation, which increases the rate of sweating, causing a greater loss of body water, which in turn leads to more severe dehydration. Humidity will increase if the ventilation is poor and there are lots of students exercising and sweating. At Evolution, we have an air filtration system that our teachers run several times during the class so the room can breath as you do.
• Wear clothing that supports evaporation, such as Supplex and other “tech” fabrics so popular today. Avoid cottons, which don’t support the release of sweat as well, but if you are someone who doesn’t sweat a lot, cotton is fine.
• Choose teachers that teach you to "follow the breath" as you flow, rather than chasing after it. This establishes a mindful, meditative approach to vinyasa practice and maximizes your efforts to really pay attention to what you are feeling.

How can I maximize the cleansing or detoxifying effect of my yoga practice?

Karen: Be sure to drink water after class and eat a meal full of fresh raw veggies that contain natural anti-oxidants (spinach, celery, apples, blueberries, flax) to aid in the removal of toxins. The twisting, forward bending, backward bending and side bending combined with inversions in yoga class acts as a pump for your lymphatic system, your "metabolic waste can" and drinking water after class is what truly flushes your system of toxins by supporting the next phase of authentic detoxing, the processing of this waste through your liver and kidneys and then out through elimination.

Sandy: Remember that external heat should play a supportive role to generating internal heat through your efforts in your practice. Modern science supports ancient wisdom, sweating should not be a measure of how effective your practice is. In fact, as you become more conditioned you will sweat earlier to cool your body and it is more dilute, i.e. more watery, to conserve the salts and minerals your body needs to function. In essence you become more efficient at sweating.

Karen: When possible, practice on an empty stomach, here's why: Tapas (internal fire) is an important aspect of the practice. On the physical level tapas is an internal heat generated by the vinyasa style and the continuity of deep focused breathing. Through increased metabolism, tapas strengthens the digestive system and purifies the blood. Food or water ingested too close to practice weakens the internal heat and diminishes its effects. Therefore one should give the body ideally, at least 2–3 hours between a meal and practice.

Sandy: During practice, drinking water affects the body the same as eating too recently. If you find yourself constantly thirsty during class, you need to hydrate more thoroughly while not in class. Rehydrating an hour to thirty minutes prior to class is a good idea if you find thirst an issue.

There was a study done in Germany last year in the news that said heat helps kill cancer tumors. Does that mean vinyasa or Bikram yoga can help keep cancer away?
Karen: The study is interesting, however, it was one study and it dealt with 104–109 temps applied directly at the tumor, not overall body heat. If you were to heat your whole body up to core temperatures greater than 103–104º F the central nervous system becomes severely impaired, rendering the body helpless in lowering core temperature. The nerve impulses are decreased, leading to an inability of the brain to send a message to the blood vessels and sweat glands to increase heat loss. If the core temperature reaches 106º F medical attention is needed immediately or death will result. Even at much lower temperatures such as in the 80s or even 90s, it is simply not accurate to assume heating your body up will melt cancer away. Remember when the soy studies came out and then everybody started popping soy pills instead of simply eating more soybeans? Now after further research, we know too much soy ingested can increase some types of cancers. Using too much heat and over sweating is not only a false sense of cleansing, it’s that soy pill mentality. Eat right, move more, practice yoga in such a way that the cleansing aspect is supported well and let’s wait for further studies on this topic.  

 

*If you are a yoga student, teacher or studio owner and would like to have your name or business name/link added to a growing list of yoga teachers and studios in support of this work, click here to send us an email.  This list will be featured as part of a future non profit web site project featuring Sensible Sweat.

 

Karen R. Kelly, M.S., PhD

Karen R. Kelly, M.S., PhD, is the Directing Exercise Physiologist for the War Fighter Performance Division of the US Navy Seals. Formerly a Postdoctoral Fellow in the Department of Pathobiology at the Cleveland Clinic Lerner Research Institute, Cleveland, Ohio.

She is also a competitive athlete and recently won the women’s division of the Towpath half marathon, came in third in 2009 in the women’s division of the Buckeye 50 mile ultra marathon, and finished first in the Buckeye 100 miler summer 2010. She says the quality of yoga at Evolution and her PIlates work were cornerstone to her training, lack of injuries and overall health.

 

Sandy Gross, E-RYT 200, 500 graduate, ACSM H/FI

Sandy is the founder/director of Evolution Yoga and loves to work out, do yoga and sensibly sweat, often.   She has worked in fashion, advertising, management and as a personal trainer and fitness instructor since 1987.  

Her passion for yoga as a life pursuit lead her to become a yoga teacher in 1999.  She has also been a student of exercise science since 1987.  She has been part of the OM yoga teacher training faculty since 2005, is an OM yoga 500 hour teacher training graduate (hosted at Evolution Yoga), and travels to assist OM yoga's founder, Cyndi Lee.  When teaching vinyasa, she strives to meld a strong physical practice with precise alignment cues, hands on assists, "middle path" thinking and inspiring music. 

She lives in Orange Village with her husband, three kids, two rescue cats and two Leonberger dogs. 

 

© 2009–2011 Evolution Yoga Studios & Boutique    |    Inside The Boutique Mall at ETON    |    28601 Chagrin Boulevard    |    Woodmere, OH    |    Contact Us    |    Site Map    |    Privacy    |    Terms