MD, PhD, FMedSci, FSB, FRCP, FRCPEd

Yoga is a popular form of alternative medicine. Evidence for its effectiveness is scarce and generally far from convincing. But at least it is safe! At least this is what yoga enthusiasts would claim. Unfortunately, this is not entirely true; adverse events have also been reported with some regularity. Their frequency is, however, not known.

A new study was aimed at filling this gap. It was conducted to elucidate the frequencies and characteristics of adverse events of yoga performed in classes and the risk factors of such events.

The subjects were 2508 people taking yoga classes and 271 yoga therapists conducting the classes. A survey for yoga class attendees was performed on adverse events that occurred during a yoga class on the survey day. A survey for yoga therapists was performed on adverse events that the therapists had observed in their students to date. Adverse events were defined as “undesirable symptoms or responses that occurred during a yoga class”.

Among 2508 yoga class attendees, 1343 (53.5%) had chronic diseases and 1063 (42.3%) were receiving medication at hospitals. There were 687 class attendees (27.8%) who reported some type of undesirable symptoms after taking a yoga class. Musculoskeletal symptoms such as myalgia were the most common symptoms, involving 297 cases, followed by neurological symptoms and respiratory symptoms. Most adverse events (63.8%) were mild and did not interfere with class participation. The risk factors for adverse events were examined, and the odds ratios for adverse events were significantly higher in attendees with chronic disease, poor physical condition on the survey day, or a feeling that the class was physically and mentally stressful. In particular, the occurrence of severe adverse events that interfered with subsequent yoga practice was high among elderly participants (70 years or older) and those with chronic musculoskeletal diseases.

The authors concluded that the results of this large-scale survey demonstrated that approximately 30% of yoga class attendees had experienced some type of adverse event. Although the majority had mild symptoms, the survey results indicated that attendees with chronic diseases were more likely to experience adverse events associated with their disease. Therefore, special attention is necessary when yoga is introduced to patients with stress-related, chronic diseases.

I find these findings interesting and thought-provoking. The main question that they raise is, I think, the flowing: ARE THERE ANY CONDITIONS FOR WHICH YOGA DEMONSTRABLY GENERATES MORE GOOD THAN HARM?

29 Responses to Adverse effects of yoga

  • I have heard positive patient reports in relation to bipolar disorder. There is some probably rather weak evidence on this which has been formally published, showing both benefits and harms. http://journals.lww.com/practicalpsychiatry/Fulltext/2014/09000/Self_Reported_Benefits_and_Risks_of_Yoga_in.4.aspx

    However, this report suggests further work is underway. See: https://news.brown.edu/articles/2014/09/yoga

    So for now, from my point of view, the jury is still out!

  • Interesting. The thing is there are different kinds of yoga, some
    more strenuous than others. Does the research take this into account.?Likewise, were the ill effects possible to rectify, for example by adjusting position? How experienced were practitioners? It is not unusual for newbies in any sport to overexert

  • One question, the matter of its uncertain efficacy… which area are we considering with regards efficacy? Physical, psychological? Muscular?

  • I read through the full report and found it very interesting and some of its findings highly disturbing (for personal reasons that are probably best kept to myself!).

    As I’m far from being an expert in medical literature, would I be right in concluding that this large-scale survey seems to be more than sufficiently adequate in terms of its quality and validity?

  • The most comprehensive source on this issue is The Science of Yoga: The Risks and the Rewards by William J Broad, a dedicated, long time yoga practitioner.

    The book is so honest and objective that Mr. Broad has been shunned by the mainstream yoga movement. It cites many quality studies. His conclusion is that yoga has high injury rates (both acute and chronic) and as a physical and spiritual practice was never intended for the lay public, especially as an alternative means of exercise as practiced in the western world.

    http://www.amazon.com/Science-Yoga-Risks-Rewards/dp/1451641435/ref=sr_1_1?ie=UTF8&qid=1430090454&sr=8-1&keywords=yoga+risks

    • Well said, yoga is not what the West has made of it, and its techniques were designed to bring about “spiritual” effects in which people may or may not be interested!

    • Thanks for that. I took note

    • Well, honesty and objectiveness are not the first words I would use to describe that book. It is a narrative review of selected dramatic cases of yoga.
      In fact several systematic reviews have been published since then, showing that yoga is not more dangerous than other forms of exercise (doi: 10.1093/aje/kwv071). A list of all case reports also came to the conclusion that some of the events may have been misinterpreted (doi: 10.1371/journal.pone.0075515).
      Nevertheless, I agree that there is a substantial lack of safety data related to yoga, and I mean not only those reported in trials. What about all those practicing in fitness studios with instructors who have had a two week yoga teacher training, those who do yoga as if it is a competition. Yoga has high potential for improving well-being, but let’s face it, also a very high potential to harm people.

  • Edzard – I’m not sure what you find so thought provoking. The page says:

    “Musculoskeletal symptoms such as myalgia were the most common symptoms, involving 297 cases, followed by neurological symptoms and respiratory symptoms. Most adverse events (63.8%) were mild and did not interfere with class participation.”

    Those aren’t adverse effects. They are the effects of exercising. People with chronic diseases, people out of shape, people stressed out by the class…were more likely to feel the effects of exercising more dramatically. Hmmm.

    “In particular, the occurrence of severe adverse events that interfered with subsequent yoga practice was high among elderly participants (70 years or older) and those with chronic musculoskeletal diseases.”

    Again, hmmm. Basically, the study says that when you are doing yoga, you are exercising.

    • A good point. A number of the complaints tie in with the instructor’scomments about people not knowing how much effort is needed and overexerting themselves. When studying Chen tai chi (previously did Taekwondo and wrestling) , I saw people forcing breathing and movements underthe mistaken impression it was thecorrect way. Perhaps theinstructors should instruct more. Likwise, in UK most responsible sports clubs require a new member to sign declarations about health.

      • Do people, especially people who are chronically ill, need to know their limits? Or is it responsibility of yoga therapist? I have heard interviews of Russian doctors who are complaining that yoga classes, especially those done in hot rooms, lead to serious injuries, requiring surgeries and long rehabilitation. But if patient has come because advertisement tells that exercising ar 35-40 Celsius allows to be more flexible?

        • Yes they do in some cases. Yoga instructors are not necessarily doctors and ill people and newbies do not always understand what they should or shouldn’t be doing.

          A physio once told that some particular exercises which seemed safe and reasonable should not be done early in the day.

    • Yes, this.

      I think it’s odd to classify yoga as an “alternative therapy”. It’s a form of exercise, and like most forms of exercise that train strength, flexibility and balance, it will have some benefits and carry some risks of injury.

      Like with crossfit (another controversial exercise program) the risk of injury decreases with the quality of coaching and teaching, and how strongly participants are advised to be aware of their bodies and its limits and to accept them so they can challenge themselves but not overdo it or push beyond their personal limits. It’s worthwhile for individuals to research the facility and to participate in a critical manner, not robotically do whatever the instructor says to do, even when it might not be suitable to them. Good yoga instructors, just like good crossfit coaches, good weightlifting coaches and good personal trainers, will have a number of options to modify movements based on a participants’ varying levels of strength, flexibility and general ability.

      There’s a lot of unfortunate woo associated with yoga, but it’s also very stress-relieving and relaxing and fun. I find I can easily tune out the woo and get a lot of benefit from the balance-challenging poses and meditation aspects.

      • @Kuri
        Smith, Kelly B.; Pukall, Caroline F. (May 2009). “An evidence-based review of yoga as a complementary intervention for patients with cancer”. Psycho-Oncology 18 (5): 465–475. doi:10.1002/pon.1411. PMID 18821529.
        Sharma, Manoj; Haider, Taj (October 2012). “Yoga as an Alternative and Complementary Treatment for Asthma: A Systematic Review”. Journal of Evidence-Based Complementary & Alternative Medicine 17 (3): 212–217. doi:10.1177/2156587212453727.
        Innes, Kim E.; Bourguignon, Cheryl (November–December 2005). “Risk Indices Associated with the Insulin Resistance Syndrome, Cardiovascular Disease, and Possible Protection with Yoga: A Systematic Review”. Journal of the American Board of Family Medicine 18 (6): 491–519. doi:10.3122/jabfm.18.6.491
        Vancampfort, D.; Vansteeland, K.; Scheewe, T.; Probst, M.; Knapen, J.; De Herdt, A.; De Hert, M. (July 2012). “Yoga in schizophrenia: a systematic review of randomised controlled trials”. Acta Psychiatrica Scandinavica 126 (1): 12–20. doi:10.1111/j.1600-0447.2012.01865.x
         
        Sorry, but yoga is a form of exercise surrounded by a lot of “unfortunate woo”, including claims as therapy for a number of disparate conditions (see examples above). As such it’s fair game for Edzard Ernst’s blog.

        • This post was not about therapy, Franko. It was about safety.

          “But at least it is safe! At least this is what yoga enthusiasts would claim. Unfortunately, this is not entirely true; adverse events have also been reported with some regularity.”

          Worst case scenario (chronic conditions, elderly), the recommendation is special attention, not avoid or discontinue. So it seems that the cited study supports the yoga enthusiasts claims about safety – adverse events and “reported with regularity” seem to be quite the exaggeration. According to the research, anyway.

          Seems that any physician recommending exercise should steer patients towards yoga – even for the elderly or folks with chronic conditions.

          • @jm,
            “BACKGROUND:
            Yoga is a representative mind-body therapy of complementary and alternative medicine. In Japan, yoga is practiced widely to promote health, but yoga-associated adverse events have also been reported. To date, the frequencies and characteristics of yoga-related adverse events have not been elucidated. This study was conducted to elucidate the frequencies and characteristics of adverse events of yoga performed in classes and the risk factors of such events.” (My emphasis.)

          • @Frank

            The cited study was looking at safety. Nothing more.

            “BACKGROUND:
            This study was conducted to elucidate the frequencies and characteristics of adverse events of yoga performed in classes and the risk factors of such events.”

            And apparently the conclusion was that yoga is quite safe.

          • @jm
            I was clearly responding to Kuri, who found it “odd to classify yoga as an ‘alternative therapy'” as it is characterized in the opening sentence of the original post. There’s a nicely written, light-hearted piece (from 2012) about the safety of yoga, whether used purely as exercise or as a method for spiritual and medical enlightenment, at http://www.nytimes.com/2012/01/08/magazine/how-yoga-can-wreck-your-body.html.
            Yoga teachers usually regard the practice as part of Ayurvedic medicine.

          • Frank,

            You said “@jm
            I was clearly responding to Kuri, who…”

            In the future, it would be much clearer if you start your responses to Kuri with “@Kuri” rather than “@jm”.

          • @jm
            What’s going on here jm? This feels very silly. Are we suffering from the curious way responses are arranged and indented in these threads? Sorry to prolong a trivial business, but you just wrote, clearly irritated…

            “In the future, it would be much clearer if you start your responses to Kuri with “@Kuri” rather than “@jm”.”

             
            But my response to Kuri did start “@Kuri”. Look up the thread a bit to April 27. It’s there in black and white indented as a response directly under Kuri’s post. He originally wrote “I think it’s odd to classify yoga as an “alternative therapy”.” I responded listing four publications that assess yoga as therapy for a range of conditions, thus justifying why yoga should indeed be classified as an alternative therapy.
             
            You responded (next indent) “This post was not about therapy, Franko.” That prompted a response (to you) from Frank Collins, to which you replied, and later from myself to you — the response you’re grumbling about. But by now we’d run out of indentations and it perhaps became less clear who was replying to what.
             
            You’ve twice stated that the post was about safety and nothing more. But it was Kuri who steered things slightly off topic, not me. He attracted two responses, from myself and Frank Collins, both saying essentially the same thing. Kuri’s claim that yoga is not altmed ignores the opening sentence of the safety paper’s background (as I note you do too in your latest response to Frank Collins!), and the opening sentence of the whole blog.
             
            Sorry to be now so wildly off topic, but I reserve the right to respond to inaccuracies in comments, including your own inaccurate suggestion that I don’t know how to address responses to the correct person.

          • @jm
            “In the future, it would be much clearer if you start your responses to Kuri with “@Kuri” rather than “@jm”.”
            FrankO said this;
            “FrankO on Monday 27 April 2015 at 17:15
            ,
            @Kuri”
            Having seen many of your posts, I’m sure there is a problem with, either, comprehension or processing written text. The above could not be any clearer. Another alternative is that you are in such a hurry to reply that it just doesn’t sink in.
            ~
            In the same way that the background says’ “Yoga is a representative mind-body therapy of complementary and alternative medicine.”, as it conflicts with your perspective, it is of no consequence to you. This is an extraordinary degree of selective bias.
            ~
            By the way, what brand of alt-med do you practise?

          • @Franko-

            Heh – sorry about that. Transposed my Franks. Not irritated at all, was simply amused. Also didn’t mean to imply that either Frank didn’t know how to address responses. Sometimes typos happen.

            “Kuri’s claim that yoga is not altmed ignores the opening sentence of the safety paper’s background (as I note you do too in your latest response to Frank Collins!), and the opening sentence of the whole blog.”

            Not ignoring the classification of yoga as alt med at all. It’s just not relevant to the cited study. No matter how you classify it, the study indicates that yoga is apparently a very safe practice. Who knew?

          • Might I suggest the classification of yoga as a form of medical treatment, alternative or otherwise is precisely ine of the reasons for the study? If yoga is being marketed as a healthy activity by its practitioners and prescribed by doctors for their patients, then the matter of whether it is indeed a safe, appropriate practice for certain conditions is obviously connected.

            One of the problems is that it may appear that this is merely an attempt to debunk pseudoscience rather than explore the limitations of yoga as a beneficial exercise in all cases.

            My reservations on the study are that, as someone else suggested, many of the things that are described ss problems (breathlessness/sputum etc) are effects found in many other exercises and not necessarily unique to yoga. Likewise, more focus needs to be placed on whether the exercises are being done correctly.

        • But you’ll see the same sorts of studies on running, cycling or pilates. That doesn’t make either of them “not exercise” or elevate them to “alternative therapy”. They are activities and worthy of study for their affect on the body, so such studies should exist. However, placing yoga in the same category as “therapies” such as acupuncture, homeopathy or ear-candleing is as strange as placing crossfit or spin class in that category.

  • It’s not that I don’t believe you Ed, but dammit I enjoy an occasional gentle stretch and it does make me feel good.

  • Well, Harvard et. al. says that something that is good for you may actually be good for you:

    http://cpr.sagepub.com/content/early/2014/12/02/2047487314562741.abstract

  • Saying that yoga is unsafe for treatment of disease is like saying any exercise is unsafe because there are regular “adverse events.” People run frequently and at some point or another you experience an “adverse event” regardless of the method of exercise or physical activity you choose. Should we all stop exercising and performing physical activities because we might hurt ourselves?

    @Edzard I know your website is intended to debunk alternative therapies but when will you share what you feel is actually effective and worthwhile for people to pursue? Telling us what doesn’t work does nothing to improve our lives if you aren’t giving us what does.

Leave a Reply

Your email address will not be published. Required fields are marked *

Please answer the following: *

Recent Comments

Note that comments can now be edited for up to five minutes after they are first submitted.


Click here for a comprehensive list of recent comments.

Categories