Yoga for Perimenopause

From time to time, I share postures included in published yoga research. I’ve used such lists to inform my own sequencing, both in group classes and when working privately with clients. Today’s share is a list of asanas that were included in a yoga protocol for a study of perimenopausal women. I’m not providing analysis or evaluation of the research, just the poses. In this study, 216 women were assigned to either a yoga group or an exercise group. The intervention was practiced for 45 minutes every day for 12 weeks.

Perimenopausal women have been shown to have increased blood sugar levels and may be at higher risk for diabetes and metabolic syndrome. It should go without saying that perimenopause is a stressful physiological state in women. Thus, the study measured blood sugar and stress hormone levels before the intervention period and again, after 12 weeks of intervention.

The study found yoga to be as beneficial or better than exercise at improving fasting blood sugar and stress hormone levels, with participants reporting calming effects of yoga practice and a general feeling of wellness.

And here, as promised, are the postures practiced in the yoga group. I’ve provided a visual of each asana using Yoga Stick Figures from Justine Aldersey-Williams. I’ve been using her clever illustrations in my teaching materials for several years now. You can download over 200 images from her Etsy store for just $5. Inconsistencies in naming & spelling of yogasana across yoga styles & teachers is to be expected, but these illustrations capture the basic shape of each pose. You’re welcome!

Asanas & approximate time held

Swastikasana (auspicious pose) 2 min

siddhasana

Vajrasana (thunderbolt pose) 2 min

virasana

Suptavajrasana (reclined Thunderbolt Pose) 2 min

supta-virasana

Tadasana (Mountain pose) 2 min

tadasana

Trikonasana (Triangle pose) 2 min

trikonasana

Parsvakonasana (extended side angle pose) 2 min

parsvakonasana

Paschimottasana (seated forward bend) 2 min

paschimottanasana

Purvatanasana (seated back arch) 2 min

purvottanasana

Janushirshana (head to the knee pose) 2 min

janusirsasana

Pavanamuktaasana (wind relieving pose) 2 min

apanasana

Bhujangasana (cobra pose) 2 min

bhujangasana

Shalabhasana (locust pose) 2 min

salabhasana

Dhanurasana (bow pose) 2 min

dhanurasana
Vakrasana (twisted pose) 2 min

marichyasana

Padottanasana (wide-legged forward bend) 2 min

pras_padottanasana
Shavasana (corpse pose) 5 min

savasana

Pranayama(breathing exercises)

Anuloma-viloma (alternative nostril) 5 min

Suryabhedana (right nostril) 5 min

Sheetali (through tongue) 2 min

Bhramari (honey bee sound during exhalation) 2 min

Namaste, Michele

More Exercises for Pronated or Flat Feet

I contend that barefooting is the best and most natural way to have strong, mobile, and healthy feet. But it takes time to transition to an unshod or minimally shod lifestyle and not everyone wants that. So, I make a point to keep up with and share biomechanics- and physical therapy-informed clinical research on foot health. In the past, I’ve suggested you add the short foot exercise for arch strengthening to your foot health protocol. I use it regularly with my clients and in my FootLove Workshops.

Here is another foot exercise to consider for pronated and flat feet and hallux valgus – the condition that leads to bunions. The Toe Spreading Exercise is easy to do. I suggest you do it standing, but you could also do it seated with your hips and knees flexed to 90 degrees. I use a yoga mat under my feet for comfort.

  1. Stand with your feet pelvis width distance apart and facing forward.
  2. Spread the toes on your right foot as far apart as you can. If you are unable to spread your toes on your own, reach down with your hand and help to spread them.
  3. Raise your heel
  4. Over a slow count to 5, lower your heel to the ground.
  5. Hold in that position for 5 seconds
  6. Relax the foot
  7. Some protocols have you repeating this up to 100 times! But you might just want to start with 5 or 10 reps. Repeat with your left foot.

A recent study suggests that along with the toe spreading exercises,  you also strengthen your gluteus maximus, commonly referred to as your butt. Your big butt muscle is responsible for externally rotating your hip joint, and a strong one is thought to alter alignment of the lower extremity, thus reducing foot pronation. The authors found that the exercise most effective for a strong butt is performed in a prone position (lying face down) by slightly lifting the knee while maintaining the hip joint in external rotation and the knee joint at 90° flexion.

I bring this exercise into the yoga world as a unique modification of salabhasana aka locust pose. Or, you could think of it as a hybrid between locust and bow poses. The study protocol called for 3 sets of 20 repetitions of single leg lifts. I think you could explore fewer reps of double legs and longer holds.

Namaste, Michele

Yoga Protocol for Balance for Poststroke Pilot Study

I read the full text of a few yoga studies each week. As a former research librarian with the current salary of a yoga teacher & blogger, I rely on free full-text sources, and when those are not available, I lean on former colleagues to help a girl out. Shh. Don’t tell.

This morning, I read the study “Poststroke balance improves with yoga: a pilot study,” which found significantly improved scores for balance in the study group receiving a group yoga intervention, with those who completed yoga even crossing the threshold of balance impairment and fall risk. “Because of improved balance, participants increasingly attempted new activities in different and more challenging environments and were aware of potential fall risk but grew confident in maintaining their balance.” Incredibly life changing for these participants and potentially for our stroke clients.

Granted the sample size was small (47), there were methodological gems with this study:

  • Participants were randomly assigned to the study & control groups
  • Two yoga groups and a wait-listed control group were included
  • Attrition/retention was reported

I am always curious to see which asanas are included in these studies, so that I can make more evidence-based choices for when I work with clients, who are dealing with similar health related issues. It is frustrating that many studies do not provide details on the yoga interventions used. But, to my delight, this inspiring study included in its publication an outline of it’s yoga protocol!

I hope you find it helpful as you craft your next balance-themed class or private session – whether or not your client base includes those who have experienced stroke.

Namaste, Michele

Yoga and bone density – another myth?

Raise your hand if you believe that yoga promotes bone health and helps prevent osteoporosis. Keep your hand raised if you think research has shown this to be true. Hold that hand high if you’ve read this research. Look Ma, no hands.  In fact, there are no randomized, controlled trials to support claims of many yoga teachers, including me, that practicing yoga promotes healthy bones and prevents osteoporosis. We don’t actually know yogasana’s effect on bone mineral density nor has anyone studied how much force specific yoga postures generate, which is thought to be important to bone density  – until now.

Exercise benefits bones in two ways. 1) Ground reaction force (GRF) is the ground pushing back back into a body with equal force. For example, walking has a GRF of 1 to 1.5  times your body weight. Running is 3-4 X body weight. When you are standing or walking in alignment, gravity compresses bones of your spine, pelvis, and lower extremities, which respond to these loads by laying down more minerals, thus increasing bone density   2) Muscle contractions load bones, again signaling them to lay down more minerals, thus increasing bone density. This bone mineral density (BMD) is used as a measurement of bone health. Research shows that both high and low impact exercise increases BMD in the spine and femoral neck, which are the areas most studied. In non-seated, non-supine yoga postures, one to four of your limbs support your body against gravity. Force is generated as you move into, hold, and move out of postures; and as you shift weight between your extremities. The nature of yoga suggests that it is a low-impact exercise that uses the body’s own resistance to generate force, but very few studies even measure GRF in exercise and none in yoga – until now.

In the first study of its kind, Sylvia Wilcox, a yoga teacher and lead researcher, measured GRF for 28 weight bearing Hatha yoga poses in a study published in 2012 in the International Journal of Exercise. Her research team used parameters from the only known previous study that divided exercises into either high-impact or low-impact GRF, where high impact was equal to or greater than 2 times body weight and low impact was less than two times body weight.

My favorite part of the study is a table that lists GRF measurements for a sample of the 28 poses studied. But, I wanted to see them all, so I located the lead author’s Master’s thesis that did indeed report GRF for all 28 asanas. The intention of this study was not to compare asanas and rank/recommend those with the greatest potential for bone building, as tempting as that may be for someone like me scanning the list. It’s main purpose was to obtain ground reaction force data from common yoga postures to see how their generated forces compare to activities like running, walking, dancing, jumping jacks, etc. As expected, Wilcox’s study was able to define yoga as a low-impact practice in terms of measured GRF.  In fact, yoga measures lower forces than any activities measured in previous studies.

Age, Weight, & Gender and Force Generation

Analysis showed no significant differences between test participants due to weight or age. For five of the 28 postures, there were significant differences between men and women explained by differences in centers of mass between the sexes. For postures connecting upper & lower body to the ground (think plank) force through the arms is greater for men than women because men’s center of mass is concentrated on the upper-body; conversely, force through the feet is greater for women than for men, because women’s center of mass is in the pelvis. In virabhadrasana/crescent, as part of Surya Namaskar (Sun Salutation), as subjects transitioned from Adho Mukha Svanasana (downdog) men generated more force in the front leg than women. It was theorized, based on researchers’ observations that because many of the males used momentum to swing the back leg forward into the lunge that they landed with greater force as opposed to the slower, more steady transition by female participants.

Upper Extremities and Force Generation

Almost nothing is written about low-impacts generated through the upper extremities. Where as handsprings done by gymnasts measure forces at 3 x body weight, yoga’s chataranga, updog, and pincha myurasana generate forces less than 1 x body weight, with only plank and crow generating maximum vertical forces of 1.08 and 1.05 body weight respectively. The researchers designed a small six month intervention with one non-yoga exercise that produced a similar range of forces in the upper extremities as those in the yoga study. In the intervention, changes in bone mineral content were recorded. It is entirely possible to replicate the magnitude, rate, and frequency of such impact forces using yoga postures instead of the non-yoga exercise as performed in the intervention study, thus showing that yoga may influence bone mineral density.

Can You Optimize Your Yoga Practice for Increased Bone Mineral Density?

Wilcox observes that in prior animal studies, low impact exercise with rest intervals produced similar bone building results as high-impact forces. If these findings apply to humans, could Hatha yoga, which is an excellent specimen of low impact applied loads with rest intervals between postures, be sufficient to stimulate bone cells in practitioners? Remember, no study, including this one, has attempted to show that yoga does or does not increase bone mineral density. However, it is known that resistance training in the form of concentric and eccentric loading of muscles, not only increases tendon stiffness that makes them stronger and able to withstand greater loads, but is also osteogenic, or bone mineral producing.  You can make your own yoga practice potentially more osteogenic by finding opportunities to turn static, passive stretches into dynamic postures that explore active mobility, use your own body as resistance, and include isometric, concentric, and eccentric muscle work so that you are generating force at all ranges of motion. I go into more detail about these methods in an earlier blog post, called Strong at Any Length.

If you want to play now, check out these free video shorts (less than 3 min each) that demonstrate how to potentially bone up your asanas.

Uttanasana Strong

Natarajasana Strong

Figure 4 Strong

Malasana Strong

Don’t Cheat Your Twist

Hamstring Training with Partner

Hamstring Training without Partner

Ustrasana Prep

Squatting on a Block

Oh, and if you are interested in learning about other unsubstantiated yoga claims and myths, check out the hard hitting new e-book Exposing Yoga Myths from the gals over at Smarterbodies.

Namaste, Michele

 

 

 

Busting other yoga myths with biomechanics

Unlike some of the improbable myths that the gals over at Smarterbodies take on in their new ebook Exposing Yoga Myths, yoga teachers could be forgiven for their misconceptions about demands placed on joints and muscles in common balancing asanas. In fact, nobody was more surprised at what is actually happening than Dr. George Salem, lead researcher for the Yoga Empowers Senior Study (YESS). Dr. Salem is Director of the Musculoskeletal Biomechanics Research Laboratory, Director of the Human Anatomy Program, directs the Exercise and Aging Biomechanics research program; and is Associate Professor in the Division of Biokinesiology & Physical Therapy at the University of Southern California.

In the study that is the subject of this post, Dr. Salem and his team used standard biomechanical analysis (joint moments of force and EMG measurements of muscle activation patterns) to examine physical demands placed on older persons, average 70 years old, performing three common variations each of Vrksasana (Tree) and Uthitta Hasta padangustasana (single leg balance).  Here’s what they discovered.

Vrksasana (tree pose)

Because it can become confusing, use this key for translating beginner, intermediate, and advanced vrksasana. You can see a visual here.

  • beginner = toes of non-stance leg touching the floor; hands on wall
  • intermediate = only stance foot touches ground; hands on wall
  • advanced = only stance foot touches ground; no wall support

They hypothesized that the beginner variation, which was done with toes on the floor and heel against the inside of the shank (lower leg) of the stance leg and using a hand on the wall for support, would be the least physically demanding . The intermediate variation, which had the entirety of the foot on the stance shank, but still holding the wall, would be more physically demanding. The advanced variation, which was classic vrksasana, with foot on shank and no wall support would be the most physically demanding. They hypothesized that the increase in physical demands would be linear. They were wrong.

Progressing

What they found was that there was a large increase in demand going from tree with the toes on the ground and wall support (beginner tree) to tree with the foot off the ground and wall support (intermediate tree). And there was not much change at all between having or not having wall support, when only the stance foot was grounded. Providing wall support doesn’t lessen demand nearly as much as lifting the toes from the mat.  This suggests that more time may be needed practicing the beginner variation before transitioning to the intermediate variation. Because older persons have diminished strength and balance, reduced joint range of motion, and a greater prevalence of osteoarthritis, some variations of what are seemingly appropriate asanas may place them at risk for musculoskeletal and neurological pain and injury. And while increased muscle loading may improve strength and endurance, excessively high joint moments of force may lead to damaging loads to joint structures and exacerbate osteoarthritis and other pathological joint issues.

Recommendation: In working with older persons in vrksasana, when they are ready to progress from the beginning variation, have them keep their toes on the floor and move away from the wall, rather than having them lift their toes while staying at the wall.

Hip Strength

Another finding was that advanced tree and intermediate tree (both with non-stance foot off the ground) were nearly identical in the physical demands of the lateral hip musculature aka abductors aka gluteus medius. Thus, there appeared to be no adaptive benefit to stepping away from the wall, when you are already balancing on one leg (toes of non-stance leg not on the ground). Thus, for students who feel safer holding onto a wall, they are gaining as much improvement in strength and endurance as those not holding the wall. Strong abductors are associated with better balance and reduced fall risk.

Recommendation: Let your students know that holding onto the wall does not undermine hip strength and will  effectively assist them in achieving better balance, decrease fear of falling and performance anxiety in class, and build confidence. 

Knee Safety

A really important finding has implications for students with knee issues. Intermediate and advanced tree pose increases loading of joint structures. Unfortunately, such loading characteristics are associated with knee osteoarthritis and joint pain, thus could exacerbate preexisting conditions. Importantly, and in contrast to commonly held conceptions, the use of a wall for support during these variations of Vrksasana does not offer protection for the knee joint.

Recommendation: For senior students with existing knee problems, suggest they stick with the beginner version of Vrksasana.

Uthitta Hasta Padangustasana (single leg balance)

Follow this key, when visualizing the beginner, intermediate, and advanced variations of padangustasana. Here is a visual.

  • beginner = extended leg supported on blocks
  • intermediate = extended leg supported on chair
  • advanced = extended leg unsupported aka supported by the strength of the student

Progressing with Props…maybe not

Again, researchers were surprised, when their hypotheses were not supported. It turns out that extending your leg onto a chair is not much of a progression over stepping onto a stack of blocks, although it appears quite a bit more demanding. (I interject that there is likely more balance anxiety for some older students to place their leg on the higher chair.) The real progression comes with the advanced variation, which uses active mobility – you holding your own leg up. What is striking to me is that while the leg may be higher on the chair, the effort is larger in the advanced variation – even though the leg is barely off the ground (see link to visual) because the student is generating internal force (muscle force) rather than relying on external force (chair) to assume the posture. It matters how you get there. It matters how you stay there.

Hamstrings

In the advanced variation, co-contraction of the hamstrings and quadriceps occurs, stiffening the joint and increasing stability, however, this increased loading may exacerbate existing knee osteoarthritis symptoms.

Recommendation: For senior students with existing knee problems, suggest they stick with the beginner or intermediate variations of Vrksasana.

Ankles

This study found Padangustasana to be an excellent posture for improving plantar flexor (think rising up onto the ball of your feet) strength and performance, which is associated with balance and postural control, gait, and fall risk in older persons. However, it’s not until students are confidently performing this one legged balance that they appreciatively load the plantar flexor muscles.  This asana is also excellent for ankle inverter strength (think sole of the foot facing in towards the midline of your body), which, like strong plantar flexor muscles, is critical for balance but also in agility and walking proficiency.

Recommendation: encourage your appropriate older students to work towards the advanced variation o Uthitta Hasta Padangustasana for improving ankle strength and agility.

Conclusions

This study’s biomechanical insights provide evidence that can be used by yoga instructors, when selecting modifications for their older students.

Here are three points to remember:

  1. Posture variations that have long been considered introductory may actually induce higher demands at some joints and planes of motion, than pose variations considered advanced.
  2. Pose variations can produce forces that are in the opposite direction of those generated during the classical variation.
  3. Use of props, such as a wall, to reduce contraindicated joint loading may have little or no effect.

As a yoga and movement teacher, my biggest take away is that there are few well-designed studies in the area of biomechanical forces and yogasana. In fact, the authors’ state that this is the first study to quantify the physical demands of yoga pose variations, using biomechanical methodologies. I will continue to seek more research like this so that I can replace time-honored ideas about what I think or what I’ve been told might be happening in yoga with what is actually happening in yoga.

The Physical Demands of the Tree (Vriksasana) and One-Leg Balance (Utthita Hasta Padangusthasana) Poses Performed by Seniors: A Biomechanical Examination. Sean S.-Y. Yu,  Man-Ying Wang,  Sachithra Samarawickrame,  Rami Hashish,  Leslie Kazadi,  Gail A. Greendale, and George J. Salem. Evidence-Based Complementary and Alternative Medicine. 2012.  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3437689/

Namaste, Michele

Load Your Feet to Improve Plantar Fasciitis

Last month, I wrote about dissonance that occurs, when I perceive discord among yoga teachers and other movement thinkers, whose work I follow. As a yoga teacher, former research librarian, soon to be Restorative Exercise Specialist™, and someone with rebellious tendencies, I am wired to ask a lot of questions about what is being taught in yoga – and why – and whether cues were informed by research or lineage. Often this results in mental compromises (and annoyed teachers & colleagues) as I try to reconcile such teachings with each other and with what I experience in my body or with my students and clients. There comes a time when a clarifying convergence of ideas emerges that confirms I am on the right path and following teachings from which I am meant to learn. This is one of those occasions. 

In previous posts (listed below), I discussed plantar fasciitis (aka plantar fasciosis) and biomechanical and environmental factors that can be addressed conservatively through yogasana, plantar fascia-specific stretching, alignment, and conditioning.

Previous posts on plantar fasciitis and exercises that can help:

https://footloveyoga.com/2015/01/05/plantar-fasciitis-what-we-know-what-we-can-do-about-it-january-5-2015/

https://footloveyoga.com/2015/01/08/what-does-plantar-fasciitis-your-down-comforter-and-your-sleep-position-have-in-common/

https://footloveyoga.com/2015/01/17/simulating-the-toe-off-event-in-walking-to-stretch-your-plantar-fascia/

https://footloveyoga.com/2015/01/13/strong-yoga-foot/

https://footloveyoga.com/2015/03/16/the-strong-yoga-foot-and-your-flat-feet-in-research/

Upon returning yesterday from what has come to be known as the Jules Mitchell Portland Tour, I found the September 1, 2015 issue of my partner’s American Family Physician peer-reviewed journal sitting on my desk with a section circled. The article was titled “Top 20 Research Studies of 2014 for Primary Care Physicians.” Basically, a group of clinicians with expertise in evidenced-based medicine performed monthly surveillance on 110 clinical research journals in 2014 (the 20th year they have been doing such surveillance). They identified 255 studies that had potential to change how family physicians practice, and narrowed that group down to 20 studies with relevance to primary care practice, validity, and likelihood that they could change practice. The section circled for my benefit was from one of these 20 studies titled “High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up,” which addressed the question of whether strength training is more effective than stretching for patients with plantar fasciitis. The bottom line answer was YES. “A regimen of strength training improves pain and function in patients with plantar fasciitis faster than a typical stretching regimen. Over time, though, patients who stretch will continue to improve and have similar improvement.” My take home, after reading the full study, is that high-load strength training, at 3 months out, resulted in quicker reduction in pain and improvement in function, when compared to stretching alone. However, 3 months was the magic time period. Before three months and at 6  and 12 months, strength training was not superior to stretching.

So, how does this research study on plantar fasciitis converge with the Jules Mitchell Portland Tour? Jules is one of the teachers in my dissonance piece. She is a biomechanist and yogi, who wrote her masters thesis on the science of stretching and turned the world of yoga on its head. One of her workshops that I attended this weekend was an impressive attempt to distill  3 years of research on the biomechanics and neuromechanisms of stretching into 8 hours of yoga workshop. The piece that is relevant here, further distilled from 3 years of research to 8 hours of workshop to two minutes of interpretive writing, is that loading connective tissues, which happens in active static stretching and isometric and eccentric training, is how we get stronger, healthier connective tissues. It is all about the load. You must input load. It is so much more complicated and nuanced than that…I challenge you to learn more by reading Jules’ seminal post on tissue mechanics, which begins her blogging journey of her thesis work.

In explaining results of the plantar fascia study, the authors confirm Jules’ findings that large tensile forces (loads) are associated with improvements in symptoms in conditions involving degenerative changes, like plantar fasciosis. Since the plantar fascia is composed of type 1 collagen fibers, it responds to high loads by laying down more collagen, which may help improve the condition. An additional benefit of high-load strength training is increased ankle dorsiflexion strength, as decreased ankle dorsiflexion strength has previously been identified in those with plantar fasciosis.

Applied exercises in your home yoga practice

With a little creativity, you can use yoga props to combine ankle dorsiflexion and controlled loading of the plantar fascia. This exercise can be used by those with or without plantar fasciosis, as it trains active mobility and improves strength at end ranges of motion in your feet and ankles, which is good for everyone. We know that strong, flexible feet are healthy, happy, and mobile.

I use a block, half round, and yoga mat. You can use a stair step or low stool in place of a yoga block and a rolled up towel or yoga mat for the half round/mat combo in the images below.

The first two pictures show my naked set-up, but I actually cover the whole contraption with a yoga mat because the half-round slides on the block without the mat, when I start doing the exercise. You probably won’t get slippage if you are using a towel instead of a half-round.

plantar fasciosis load1 plantarfasciosisload2 plantarfasciosisload3

  1. Place the toes of your right foot on the mat-wrapped half-round (towel), so that they are maximally dorsal flexed, meaning your toes extend back towards you.
  2. Place the ball of your foot on the block (stool or step).
  3. Hold onto a chair/rail for balance and slowly, over a period of 3 seconds, lift your right heel, so that you rise up onto the ball of your foot (concentric phase).
  4. Remain in the raised position for 2 seconds (isometric phase).
  5. Slowly lower your heel, over a period of 3 seconds, to slightly below the level of the block (eccentric phase). The rise, hold, & lower is one rep.
  6. Repeat up to 12 times (reps) for up to 3 sets.
  7. Once you can do 3 sets of 12 reps, play around with increasing the load by wearing a loaded backpack. You might decrease the number of reps at this new load, but increase the number of sets. The idea here is to progressively load the tissues as you get stronger.
  8. Perform this exercise every other day.
  9. If you find you are not strong enough to do unilateral heel raises, try using both feet at the same time until you are stronger.
  10. This protocol is just a suggestion. Modify the load, reps, sets, and props, customizing it to suit your strength, flexibility, and movement history.

plantarfasciosis load5 plantarfasciosis load4

P.S. Look at how in the first picture, both ankles are dorsal flexed; and in the second both are plantar flexed. Not intentional. Just a neural pathway, I guess.

Consider adding this exercise to your foot health protocol of stretching, strengthening, and mobilizing your feet.

Namaste, Michele

Sweat is 99% Water, 1% Natural Stuff and 0% Toxins

Yoga claims many health benefits, most of which are anecdotal, the collected stories and somatic truths of its millions of practitioners.   A few claims  are solidly supported by research – like improvements in pain, reduction in inflammation, enhanced body awareness, and those work horses of yoga – better strength and flexibility. Yoga’s promising effect on other diseases and conditions, like cancer, diabetes, and heart disease, are seeing a greater number of quality studies. But one thing for certain is that releasing toxins through sweating or twisting asanas is pure myth.

What is Sweat?

Sweat is 99% water with a dash of essential salt minerals, urea and other wastes from protein metabolism, and some trace elements like zinc. Sweat’s main job is thermoregulation – to cool the body. When your internal temperature rises, your sweat glands secrete a non-toxic mix of mostly water to your skin’s surface, where heat is removed by evaporation – aka sweat. When you sweat in yoga class, you are not releasing alcohol, angst, toxic chemicals, drugs, illness or supersized happybad meals – you are secreting mostly water for the physiological purpose of cooling your body. If you are hoping to rid yourself of the aforementioned toxic brew, rest assured that the actual parts of your body that do this work – your liver, kidneys, colon and mind – are actually doing this work. Unless…and this is a big unless, you have been occupationally exposed to high levels of heavy metals – arsenic, cadmium, lead, mercury, etc. A 2012 review that looked at 24 studies on toxicants and sweat, found levels of heavy metals in the sweat of subjects who had been occupationally or geochemically exposed. For the typical Western yoga practitioner, who has not had an occupational exposure, has not been exposed via geochemistry, and is not in kidney failure, the science has simply not shown sweat to be a major route for ridding the body of unwanted toxins.

Sweating is not a case of more is better. Excess sweating means elimination of water and its associated weight – aka water weight, which is not a true loss of fat or mass. In an ironic turn of events, heavy sweating is associated with a significant diminishment of urinary output, thus concentrating uric acid and other cellular wastes in your blood – the buildup of which is toxic to your body.

What About Wringing Toxins Out Your Organs?

I often hear yoga teachers refer to the detoxifying effects of spinal twists. While there may be a metaphorical truth to this claim, it’s more nuanced and complex than that. Whether you are flexing, extending, or twisting your core muscles, the act of generating force in a muscle causes the smallest of blood vessels (arterioles and capillaries) to vasodilate (get bigger), which pulls oxygen rich blood out of the arteries (lowering arterial blood pressure) and into these tiny vessels, feeding the work of your cells.  Your body’s waste removal system (lymphatic system) works in parallel with your cardiovascular system, thus while blood is being drawn into the muscles, cellular waste (toxins) is removed. This happens wherever and however you move your muscles and is not the territory of twists alone. Although a twist is an effective way to bring blood to your intervertebral discs, which do not have their own blood supply but rely on diffusion from the blood supply at their margins, flexing or extending your trunk may accomplish the same thing, as movement is thought to enhance the process of diffusion.

Now you see how using your muscles in yoga facilitates cellular waste removal and keeps your  spinal discs nourished, but what about wringing stale blood and toxins out of your organs to allow fresh blood in? Well, I lean on the wit of Kim & Mel at Smarterbodies to eviscerate this myth. “So twist and do so knowing that you are helping create movement in your internal organs, but in NO WAY are they “wrung out.”  That is not possible and if that happens to you or inside of you please go to a hospital, because you are going to die. Also, do the organs fill with fresh blood after a trunk rotation? No, they are CONSTANTLY filled with “fresh” (I’m assuming this means oxygenated) blood, because we have these vessels called ARTERIES whose job is to deliver this type of blood constantly from birth to death.”

As always, I am happy to elaborate on this or any previous content. Post your questions/comments here or email me at michele@footloveyoga.com.

Namaste, Michele