Tuesday, February 28, 2012

knee replacement

February 27, 2012, 5:49 PM

Knee Replacement May Be a Lifesaver for Some

Stuart Bradford
By the time 64-year-old Laura Milson decided to undergo total knee replacement after 12 years of suffering from arthritis, even a short walk to the office printer was a struggle.
After her surgery last August at the Rothman Institute at Thomas Jefferson University in Philadelphia, Ms. Milson spent a week in rehabilitation and says she hasn’t stopped walking since. “My son says to me, ‘You have to slow down,’ and I say, ‘No, I have to catch up!,’ ” she said. “It’s a whole different life.”
For Ms. Milson, who lives in Shrewsbury, Pa., replacing the joint in her right knee came with a surprising bonus: a 20-pound weight loss in two months. “I joked with my doctor, ‘I think you put a diet chip in my knee,’ ” she said. “The weight just sort of came off.”
Now she has joined Weight Watchers to drop a few extra pounds and is training for a three-day breast cancer walk in October.
For years surgeons have boasted of the pain relief and improved quality of life that often follow knee replacement. But now new research suggests that for some patients, knee replacement surgery can actually save their lives.
In a sweeping study of Medicare records, researchers from Philadelphia and Menlo Park, Calif., examined the effects of joint replacement among nearly 135,000 patients with new diagnoses of osteoarthritis of the knee from 1997 to 2009. About 54,000 opted for knee replacement; 81,000 did not.
Three years after diagnosis, the knee replacement patients had an 11 percent lower risk of heart failure. And after seven years, their risk of dying for any reason was 50 percent lower.
The study, presented this month at the annual meeting of the American Academy of Orthopedic Surgeons, was financed with a grant from a knee replacement manufacturer. It was not randomized, so it may be that these patients were healthier and more active to start with.
Still, the researchers did try to control for differences in age and overall health. And the findings are consistent with large studies of knee replacement and mortality in Scandinavia. Given the big numbers in the study and the size of the effect, the data strongly suggest that knee replacement may lead to improvements in health and longevity.
The theory behind knee replacement, said the study’s lead author, Scott Lovald, senior associate at Exponent, a scientific consulting firm in Menlo Park, is that it improves quality of life. “At the end of the day, we’re trying to figure out if quantity of life increases as well,” he added, noting that the team was conducting a similar review of Medicare data on the long-term benefits of hip replacement surgery.
The founder of the Rothman Institute, Dr. Richard H. Rothman, who has performed 25,000 joint replacement surgeries in his career, urged caution in interpreting data that are not randomized and controlled. Not every patient with knee arthritis is a candidate for joint replacement surgery, he said.
“People can tolerate a lot of knee disability for reasons we don’t totally understand,” he went on, adding, “If the pain is acceptable, you live with it; if it’s not acceptable, we’ll operate on you.”
Dr. Rothman said that whether patients experience better health after surgery depends on motivation — how motivated they were to stay fit before surgery and how motivated they are now to become more active.
“For the motivated patient, it allows them to walk through that portal and become better conditioned and lose weight,” he said. “It’s not a weight-reduction program. It’s a potential avenue to improve your level of fitness, weight, cardiovascular health and mental health.”
Edward Moore, a 94-year-old retired chemist in Woodbury, N.J., underwent knee replacement three years ago after pain began limiting his activity. Given his age, his own daughter had worried that the recovery would be too difficult. But Dr. Rothman agreed he was healthy enough for the procedure.
“I didn’t do much mulling about it,” Mr. Moore said. “It just seemed like the knee would be hampering me for the rest of my life, and that sounded like a bad idea.”
Mr. Moore said he had an uneventful recovery, and in September, two days after his 94th birthday, he took his wind surfer to Lakes Bay near Atlantic City. “I got up on the board, and I sailed,” he said.
William Mills, 63, of Philadelphia, had been suffering for about four years with severe pain in both knees when he opted for double knee replacement in 2006. He said his activity had dropped off, and while he could still play golf, he could no longer walk the course. Even going to a restaurant had become a burden if he couldn’t find a parking space nearby.
“I think one of the things people don’t understand about knees is how bad it is,” said Mr. Mills, a bank executive. “It changes everything. I couldn’t walk two city blocks. It was just slowly but surely changing my life where I was unable to really enjoy things.”
But while the rehabilitation of both knees was “the hardest thing I’ve ever done in my life,” he has no regrets. Six months after surgery he took part in a 250-mile bike ride in Germany. He has made a few compromises — he no longer skis, and plays doubles tennis instead of singles — but he says he now rarely thinks about his knees.
“Before surgery, I felt like I was 10 or 15 years older than I was,” he said. “Now I probably feel like I’m 10 or 15 years younger than I am.
“I can understand why people might live longer, because you want to. You really feel good again.”

Tuesday, February 21, 2012

yoga

February 20, 2012, 12:47 PM

It’s Not Too Late to Become a Yoga Believer

Yvetta Fedorova
One morning, a well-meaning swimming buddy called out for all in the Y locker room to hear: “I can’t believe Jane Brody doesn’t do yoga!”
She was right: I didn’t do yoga and, not knowing what it might offer me, I was loath to try it. I also feared that the meteoric growth of yoga had outpaced the training of quality teachers able to protect my aging body parts.
Now, it seems, my thinking and schedule may be due for a change. After reading my colleague William J. Broad’s new book, “The Science of Yoga,” and observing a class at my local Y, I see there may be a lot more to this centuries-old activity, more to its benefits and its risks, than I had ever imagined.
And if the science recounted in this book is correct (knowing Mr. Broad, I have every reason to think it is), my creaky joints and muscles may reap some important rewards from an individualized yoga prescription. I’m especially concerned about my back, which is riddled with narrowed vertebral spaces and prone to spasms and sciatica.
Mr. Broad said decades of yoga has helped protect his back from excruciating pain initially caused by a ruptured disc. Yet in 2007, even he succumbed to a yoga-induced back injury as he was coming out of a pose called the Extended Side Angle.
“Recovery took weeks,” he wrote. “But the humbling experience gave me a deeper appreciation for yoga safety.”
Not all yoga poses are beneficial or safe for everyone, and enthusiasts are hard put to know whether the teacher and class they select are more likely to help than to hurt them.

Safety First
What I need is yoga therapy, and I can only hope to benefit from it if the teacher is well-qualified. And therein lies the rub.
As I learned from Mr. Broad’s book, “the United States has no regulatory body for yoga therapy. The field is, on the whole, completely unlicensed and unregulated. There is no such thing as a Registered Yoga Therapist. Applicants for registration usually face no requirements to establish their education credentials, to pass national exams, or to show other evidence of expert proficiency. Registration, in short, bears no comparison to the rigorous world of health-care certification.”
Anyone who chooses to can hang out a shingle and call himself a yoga therapist. Licensing requirements exist for beauticians and hairdressers, but not for yoga therapists.
The Yoga Alliance, a national organization for yoga in the United States, fills in this gap with specific training standards that, if met, earn the title registered yoga teacher. The standards involve either 200 or 500 hours of instruction and supervised practice, with specialized training for children’s and prenatal yoga.
To be sure, the yoga world is rife with true believers, many of whom bombarded Mr. Broad with complaints about an article he wrote in The New York Times Magazine last month chronicling a raft of devastating yoga-induced injuries. But he was also deluged with dozens of personal injury stories that included strokes and ruptured discs.
Among them was that of a 39-year-old man who said in an e-mail that he’d “always been very active,” having “skied, boxed, climbed, surfed, etc.” The man began practicing yoga in 2000 and said he reveled in the meditative aspects of it, in contrast to his more “brutal sports.”
Then, in 2010, he enrolled in a new class and developed “severe spinal stenosis” with debilitating back spasms when the teacher “literally forced me into maintaining an extremely painful Downward Dog.” This is a classic pose in which hands and feet are flat on the floor, knees are straight (though not locked) and the body is bent at the waist at a right angle.
In a more serious injury resulting from the Downward Dog, a woman in Washington, D.C. suffered a spinal cord infarction, a blockage that caused sudden leg paralysis. She has since regained only partial use of her legs.
Mr. Broad concluded, based on his research, that the benefits of yoga “unquestionably outweigh the risks. Still, yoga makes sense only if done intelligently so as to limit the degree of personal danger.”
Thus, it is critical to choose your class and teacher carefully. Grace Grochowski, a registered yoga teacher at my local Y who has been teaching for 20 years, recommends that prospective students ask about an instructor’s formal training, tell him or her what they hope to get from the discipline, and report any injury, ache or health condition that might affect their participation.
The teacher should be willing to suggest changes in the moves you attempt or even say that the class may not be right for you.
“A good teacher listens and makes appropriate suggestions,” Ms. Grochowski said. Though her popular class is large, she regularly walks among the participants, correcting and modifying their poses and suggesting alternatives.
Most important, Randi Baker, one of her students, told me, is to “never go for the burn. If something hurts, don’t do it.”
Real Benefits
Many of the oft-touted virtues of yoga have yet to be established in well-designed clinical trials, Mr. Broad wrote, and some popular claims have been shown to be bogus, like the belief that yoga breathing suffuses the body with extra oxygen or that it revs up metabolism and can foster weight loss. (Yoga actually slows metabolism, though its relaxing effect may reduce stress-related eating.)
Good scientific studies, including many supported by the National Center for Complementary and Alternative Medicine, an arm of the National Institutes of Health, have demonstrated that regular yoga practice can improve cardiovascular risk factors like elevated blood pressure, blood sugar, bloodcholesterol and clot-inducing fibrinogen, and it can raise blood levels of protective antioxidants.
Yoga was shown to improve balance in elderly women and thus may reduce their risk of falls, a leading cause of injury-related death in older people. And, I was pleased to learn, perhaps by enhancing blood flow and the production of growth factors, yoga can counteract the deterioration of spinal discs, a plague of millions of Americans, young and old.
Possibly through its stimulation of the vagus nerve, yoga appears to counter inflammation throughout the body, and may reduce the effects of diseases likelupus and rheumatoid arthritis. And by relieving physical and mental stress, which can erode the tips of DNA, which are called telomeres and program cell death, yoga may slow biological aging and prolong life.
A more immediate benefit, to which Mr. Broad devotes an entire chapter, is yoga’s apparent ability to revitalize a person’s sex life by producing surges in sex hormones and the brain waves associated with sexual arousal. Just don’t try to act on this stimulation in class.

45 Comments

Share your thoughts.
    • Mike W
    • Boston
    What bothers me is the popular insistence on mixing up the physical effects of yoga with all manner of new-age claptrap, which is well attested in many of the comments here. People get carried away with the "exotic" nature of it, and insist that "there must be something to it", throwing away any shred of rational thought.

    These true believers are quick to dismiss injuries - anybody who hurts themselves following their guru's instructions must have been misunderstanding or doing it wrong - there is no possibility that the instructor was simply following a pre-scientific prescription which might not have been suitable for the situation.

    Folks, yoga (like tai chi) is a form of exercise. It's not magic. It does not "purge toxins" any more than comparable physical activity. Its instructors are not mystically enlightened, and more importantly, are not doctors. Nobody has ever been able to conclusively demonstrate the existence of "prana" or "qi" or "bio-energy" - and for anyone who can, there is a sweet $1M prize available from of jref.org !

    Exercise can certainly have positive effects, and coming up with systems that make the exercise more interesting, offer low-impact training for the elderly or infirm, or provide for cultural studies is great - I practice Asian martial arts because it's far more fun than simply doing cardio. I'm not suggesting yoga is *bad*. But this is the 21st century, can't we dispense with the pseudo-scientific baggage already?
      • Wellness Minded
      • Texas
      I am so late with Yoga, but better late than never. My sister had been begging me to go to a yoga retreat in Thailand with her for about 3 months. I was so busy with work and family priorities that I just wouldn't make any time for it. Long story short I ended up going last month and it was the greatest sense of renewal and rejuvenation that I've ever experienced to say the least. I would recommend that everyone go on a yoga retreat at least once in their life so that you can seclude yourself and really get the undisturbed therapeutic benefits of the practice. And to experience that in Thailand was totally serene.http://www.yoga-thailand.com/
      Om :)
        • bhc
        • blanchester,oh
        The last sentence is a real enticement to do a lot of yoga. Thanks for trying this practice and letting us know about your findings and thoughts. B
          • LaurelM
          • Mountain View, CA
          I am a physician and mom, who began practicing yoga in my late 40's, with knee and lower back injuries already from other activities (yes, cycling too can injure your knees!). I quickly learned that yoga could help with these injuries, but it could also cause them to flare up. When I asked myself which teachers, classes, and videos were helping rather than hurting, I found myself focusing on Iyengar yoga. Iyengar developed his approach to yoga, which emphasizes modifying poses with props such as blocks, straps, etc, after he was injured himself in a motor vehicle accident. A lead teacher in my local Iyengar studio teaches back care classes (she has scoliosis herself). I love working with older teachers who have experienced injury themselves. Yoga makes me feel more fully alive, and has expanded my physical and mental--spiritual?--capabilities. By all means practice yoga, but with care and with a careful teacher.
          1. Many people view Yoga s only exercise and this can be damaging to the output that yoga offers. Besides a routine that allows the body to cleans itself of toxins and stress, yoga also has properties of extreme relaxation, rejuvenation and renewal.

            It has taken us hundred of years to finally make yoga mainstream and I hope that its counterpart - ayurveda, makes its way to our lives sooner rather than later. An ancient indian health system, ayurveda is an amazing supplement to yog and our health by assessing our bodies make, type, and problem and integrating the roots of nutrition into our every day. Through change in diet, herbs and balance (yoga and meditation) we begin to renew ourselves on a cellular level.

            Unfortunately, the drug companies would never touch this because it isn't synthetic.. That's an oxymoron if i've ever seen one.

            -Brian
            http://www.progressivetransformation.blogspot.com
              • Mike W
              • Boston
              It's much more likely that the drug companies would never touch this because the FDA requires that they demonstrate proof that their products do what they claim.

              If you (or anyone else) can demonstrate these claims of "cellular renewal" or "toxin cleansing" in an objective manner, I suggest they apply immediately for the JREF $1M prize. If these are real effects, winning the prize would be incredibly easy.

              http://www.randi.org/site/index.php/1m-challenge.html
            • Robert S
            • NY
            Centuries Old ?

            Is postural yoga really centuries old? If you think so take a look at http://www.openthemagazine.com/article/living/not-as-old-as-you-think and http://www.amazon.com/Yoga-Body-Origins-Posture-Practice/dp/0195395344/r...
            They assert that postural yoga is a very recent development and that the only physical aspect of the centuries old yoga was breath control.
              • Cheryl
              • Boston
              Downward Dog is not done with a bend at the "waist." The "bend" is the hinge at the top of the legs, so the spine elongates. It looks like an upside down "V," not a "U."
                • sui generis
                • Mass
                At age 69, my testimony on behalf of yoga would inform you that a mere once-a-week class of gentle yoga at my neighborhood studio improves my quality of life significantly. I know, it's anecdotal evidence only, but my outdoor pursuit (other than dog walking) is golf. Regular yoga practice has kept my back, neck, shoulders and hips in shape enabling me to walk and enjoy the game.
                  • Naomi
                  • Concord MA
                  In my experience, one of the biggest factors that contributes to yoga injuries is that often, when people get injured, they simply do not return to class. In that situation, the teacher never gets feedback about what the specific instruction was that could have been misinterpreted and was therefore dangerous. Teachers modify their teaching all the time, but without this information the changes may be inadequate. I encourage all yoga teachers to explicitly request that students contact them about any medical problems that may arise after a class.
                    • ETIsHome
                    • NYC
                    There is a rare and thus sad comment I would hear at beginning classes 30 years ago. Not really in Broad's book either. But it means the most to me.
                    Which is that lying and thinking (imagining) you are doing a pose, is just as good as really doing it. _just as good_.
                    All the analysis of specifics means not as much as that simple truism which students should always always keep in mind.
                    1. Ms. Brody made an error in describing Downward Facing Dog. The right-angle bend is made at the hips, not at the waist. If she took a yoga class she would learn the difference between these two parts of the body. ;=)
                        • seeking
                        • Geneva
                        Not all postures are right for everyone. One may not always be aware of one#s own weaknesses or susceptibilities, and not all yoga teachers may be checking every yoga student to see what pose suits one best. E.g. those with sight (long or short) may not do themselves a favour by doing the head stand.

                        However, not all yoga teachers may be methodical enough to do a complete study of the student's status of health. A national accreditation agency may go someway in standardizing yoga therapy, but not enough to avoid avoid injury, I am afraid.

                        Even if you are not in doubt as to what might suit you best, it is good to go slow, one posture at a time. If yoga is so good that it helps cure disease, then the wrong use of it can just as well have serious undesirable consequences.
                        1. When it comes to yoga, one must be extremely careful in choosing the right teacher. I tried at least 20 different studios and 50 teachers before making up my mind and sticking to one in particular.
                          So, do your due diligence: search, read, ask and try...and I'm positive you'll find the perfect one for you!
                          Mike
                          www.theironyou.com
                            • california duet
                            • San Diego, CA
                            My problem with yoga is its practitioners - they are maniacal and cultish, kinda like Apple fanatics!

                            I have never met a yoga person (and there are millions of them here in Southern California) or an Apple person who admits the shortcomings of their product. This lack of objectivity is suspect; I would be more open to trying something if I was given a rational list of the pros and cons, rather than a overly exuberant one-sided gush fest of platitudes.
                              • Sara
                              • LA
                              Of course it is never too late to start yoga. My mother began her practice after 50 and it has helped her tremendously will many health issues she was facing. There is an interesting outline on yoga resources at http://yogatrainingguide.com/yoga They also offer a directory of teachers and schools. There is also a full directory of yoga therapists via the Association athttp://www.iayt.org/

                              What most people dont realize is that stress is the biggest issue that causes health problems because we are not getting breathe deep into our lungs. We are so stressed out that most people do "short breathing" so oxygen is not getting into our blood cells. Ever hear of a "runners high"? Thats because they are high on oxygen!
                                • mother
                                • Bay Area, CA
                                I am 63 and been moderately active most of my life. I taught myself yoga in my early 20's, often including the shoulder stand and plow in my routine. It felt wonderful, relaxing and I loved it. In my 40's I had 2 separate incidences of herniated neck discs, 2 yrs apart, with no apparent cause. I am convinced those plows and shoulder stands were at least a contributing factor, even though I had cut way back on yoga in my 30's and 40's. In my 50's I tried yoga again (minus the neck bending and with a well trained teacher) and found that my knees did not respond well at all to the twisting and force required. I quit as soon as I realized what was going on. Since then I have been practicing a joint mobility program called Z Health, which is gentle and excellent for balance, and coordination. I have also practiced Kettlebell for about 3 yrs. with Cecilia Tom in SF. I have gone from being an intermediate to an advanced downhill skier in the last 3 yrs.
                                1. Yet another writer opining about yoga who knows little or nothing about yoga.
                                  1. Dear ms.broody,

                                    How truly wonderful that your respect for your colleague helped to open your eyes to yoga. I hope that your journey brings joy, good health, gratification. And relief from suffering.

                                    Nonetheless, I am almost speechless with incredulity and astonishment to read that you were formerly"loathe"to know about yoga. It is almost a topic of discussion, possibly worthy of a memoir in itself.how an editor on the desk of PERSONAL HEALTH for no less an institution than the NY TIMES, somehow managed to be oblivious to one of the biggest PERSONAL HEALTH TRENDS of the past decade.

                                    With ask due respect: that is a fascinating disconnect.

                                    Among the many great pleasures, and challenges, of yoga, is to observe how many people begin their practice of yoga with mostly physical and secular conceptiona, such as you enumerate. But yoga is far more than just the body. I genuinely hope that you stay with your practice long enough to begin to access, and appreciate, those other rewards. I sense that patient practice may help you understand better why you had a"blind spot"to yoga for so many years, and reveal other things you did not see before.

                                    Enjoy the ride.

                                    I look extremely forward to reading future columns and hearing how you evolve. I hope and trust that all of us will be better for it.
                                    1. Dear Jane Brody,

                                      You write:

                                      "The Yoga Alliance, a national organization for yoga in the United States, fills in this gap with specific training standards that, if met, earn the title registered yoga teacher. The standards involve either 200 or 500 hours of instruction and supervised practice, with specialized training for children’s and prenatal yoga."

                                      And I would respectfully point out that you are incorrect about that statement.

                                      Yoga alliance has only recently changed their legal status, but more importantly, John Matthews, Lynn Bushnell, Gyandev McCord spent $336,325.00 on NOT fighting yoga regulation, but to promote their own greed.

                                      It is Yoga Alliance's intention to inspire fear and complicity surrounding their loose non-legal credentialing.

                                      So before you make statements about credentialing entities of yoga, please do your homework and know the facts.

                                      John Matthews (who resigned after I printed their tax returns), Lynn Bushnell (who works for YogaWorks) and Gyandev McCord (who represents Ananda Yoga) all represent a legal threat to the education standards of yoga.

                                      Yoga Alliance has not acted with integrity, makes all their employees sign non-disclosure agreements, and really has not added anything to yoga education that wasn't there in the first place.

                                      Brian Castellani
                                      Yoganomics.net
                                        • Linda
                                        • Oklahoma
                                        • Trusted
                                        Thank you to all the people who recommended books, videos and websites to me. Sometimes it can feel all alone out here in the middle of the country. It's nice to know there is a community that cares. Thank you again.
                                        1. I was expecting that you were going to actually engage in some Yoga, Ms Brody - and wanted to hear how your knee replacement was accommodated in practice. Looking forward to a followup.
                                          As an off and on practitioner (now off) I know that at the 1st whiff of a competitive atmosphere in a class, run away (before you have to limp away ...) The teacher is key- in experience, understanding of anatomy as well as practice, and attitude.

                                          I think that Kripalu up in the Berkshires does provide excellent introduction for newbies, as well as those with experience.
                                            • Lisa Hirsch
                                            • Oakland, CA
                                            I meant to also say that Ms. Brody is right to be concerned about the lack of standards and qualifications for yoga teachers. There's a similar problem with Pilates teaching. Too many instructors in my area were trained in 200-hour classes and don't spend nearly enough time with experienced teachers. They teach Pilates as if it's weight lifting, or they focus on repetitions with a lot of resistance instead of focussing on form.
                                              • Meena Modi
                                              • Ridgewood
                                              I totally agree with you, Lisa. I have seen many of my yoga students come to me with severe back pain after Pilates (done in a class or with a personal trainer). It is not clear whether the teaching was the cause (misinformation, ignorance, lack of proper training , or lack of supervision in a large class), the student not doing it properly, or an overzealous student.

                                              Then when I talk to physical therapists, they say they see the same in their patients who come because of yoga injuries. The same factors apply to yoga. It was inconceivable when I started out with yoga in the late 1970s that anyone could teach after 200 hours.
                                            • Lisa Hirsch
                                            • Oakland, CA
                                            It's possible to get hurt doing any physical activity, of course. It's important to know your body and know what it is capable of, and it's important to make progress in any activity at a rate that makes sense for you. I'm appalled by the mention of a yoga teacher forcing a student to maintain a painful posture. If it hurts, STOP is always a good idea, as is knowing the difference between soreness and injury.
                                              • Tom
                                              • Albany NY
                                              To Ms. Brody,

                                              It's never too late.

                                              Here is a link to Phoenix Rising Yoga Therapy, a member of the Yoga Alliance. They may be able to assist you in locating a certified yoga therapist in your location.

                                              http://www.pryt.com/directory/directory.html

                                              There are many schools and styles of yoga, each with its own quality or defining characteristic. I have been practicing yoga for 20 years and am a certified teacher through the Kripalu Center for Yoga and Health.

                                              http://www.kripalu.org/

                                              I am in middle age, have hernatied spinal discs (not yoga induced), and am able to lead a functional life with no medication as a result of my yoga practice. Yoga's benefits are holistic. However in my case, yoga asanas (postures) strengthen the lumbar muscles to keep the discs in place, and limit the pinching on the spinal nerves and associated pain.
                                              "Yoga and Stretching Equally Effective for Back Pain"
                                              http://well.blogs.nytimes.com/2011/10/24/yoga-and-stretching-equally-eff...

                                              Yoga breathing (pranayama) can be both energizing and relaxing. There are different types of pranayma depending on the condition or desired outcome in the mind and body. Pranayama is fundamental to the practice of yoga:

                                              A couple of Kripalu-isms:

                                              "If you are not breathing, it's not yoga."

                                              "When the student is ready the teacher will appear."

                                              I anticipate your next article about your salutary explorations and encounters along the yogic path.

                                              Namaste
                                                • Barbara
                                                • Armonk,NY
                                                I was in New York once and see a jogger with an oxygen bottle strapped to his shoulder and I was wondering why he was doing this. I went to a book store and came across the book ,"Oxygen Yoga: A Spa Universe" and discovered there was a new movement sweeping the US involving yoga. People in cities are really concerned about the air quality that they exercise in. It seems that breathing toxic air during exercise is like poisioning the mind and the body. The science is really becoming mixed with exercise and yoga. Think ecology when exercising.