Will yoga wreck your body? Yes, or No. Eating chocolate can make you fat (or not) and reading this on your computer can strain your eyes (or not). Similarly, the effects of yoga have everything to do with how one approaches the practice.

The dangers of doing yoga are highlighted in the popular media about every five years. A decade ago it was the L.A. Times with “In Over Their Heads,” a piece on how ill-trained yoga teachers are leading students to practice in injurious ways. A few years ago Time magazine published “When Yoga Hurts” and just last week the New York Times chimed in with a piece by William J. Broad, “How Yoga Can Wreck Your Body,” the latter causing a flurry of reactions across the blogosphere and in other online forums and publications.

It will be a few weeks before the yoga community has the opportunity to read the Broad’s forthcoming book, The Science of Yoga, but we can already see from his NYT article that this Pulitzer Prize-winning journalist can be fairly charged with unbalanced and selective reporting in the case he makes against yoga. It is also not at all surprising that only one of one his seven advance reviewers, David Gordon White, has any claim to yoga expertise—and while White is an insightful philosopher and historian of religion, he is not a yoga teacher or asana expert.

Broad draws extensively from the experience and opinions of one yoga teacher, Glenn Black, who has reportedly caused self–inflicted injuries doing asanas that were inappropriate for him. Black, who admits having no formal training that would enable him to effectively guide students in doing appropriate asanas or doing asanas appropriately, generalizes his personal experience to the yoga community with statements such as “the vast majority of people” should give up yoga altogether. Broad and Black together (it’s often unclear which says what) betray a limited reading of the classics (such as claiming that Iyengar never addresses risks in asanas) and confused knowledge of basic things like functional anatomy (as when they confuse hyper-extension with hyper-flexion is their discussion of shoulder stand and cobra pose). So we can reasonably approach the article and forthcoming book aware that we are being given a very limited perspective buoyed by bombastic assertions certain to stoke controversy (and sell books) but not shed much helpful light on teaching and practicing yoga.

The idea that “yoga can wreck your body” reifies yoga—makes it into a thing that is given the power to affect other things (say, your body). But yoga is not a thing. Rather, yoga is a world of practices that one can do; you do yoga, yoga does not do you. Once one gets this basic idea, then it is a simple step to realize that how one does yoga along with what sort of yoga one does will have different effects. If you skip over the first couple hundred pages of Iyengar’s Light on Yoga to the few pages on shoulder stand, look at the pictures, read the brief instructions, then attempt to do it without all the preparation discussed in the previous two-hundred pages, then you’re likely to end up like Black and others who feel that yoga is hurting them. Forget for a moment, as Broad and Black seemingly have, that Light on Yoga was written 50 years ago and that Iyengar has published extensively since then and given more nuanced guidance around things like how to reduce hyper-flexion of the cervical spine—not exactly responsible journalism or scholarship on Broad’s and Black’s parts.

There is no question that many students (and teachers) are getting injured doing yoga. This has a lot to do with two factors: 1) how yoga is being taught, and 2) how yoga is being practiced. With both the teaching and the practicing, there is another variable: the type of yoga being taught or practiced. When a 55-year-old retired school teacher in moderately good physical condition dives in to a vigorous Power Yoga class with the intention to lose 30 pounds in 30 days, it is a likely disaster waiting to happen. When a pregnant student goes to Bikram classes unaware that extreme heat is contra-indicated during pregnancy (or goes to an Anusara class and twists deeply during the first trimester unaware of how this pulls on the broad ligament that attaches to the uterus), miscarriage is more likely. So just to start, it is important for students to find a class style, level and intensity that is a good match for his or her intention and actually existing condition.

Once in a class that is generally appropriate for a student, then it is primarily about how the student approaches the practice. Here the classical yoga values of ahimsa (not hurting), satya (being truthful, including with oneself) and aparigraha (not grasping for what has not come to you) offer a wonderful set of sensitizing principles that allow the practice to be both transformational and sustainable. A generation before the teachers Broad refers to as “reformers” were talking about how to address potential injury when doing asana, Joel Kramer’s 1979 seminal article “Yoga as Self–Transformation” was published in Yoga Journal, giving the yoga community an insightful set of practical principles for being guided from inside. Popularized in Erich Schiffmann’s best–selling Yoga: The Spirit and Practice of Moving Into Stillness, Kramer’s techniques are a sure way to steadily deepen one’s practice without getting hurt.

Having found the right class and perhaps even following Kramer’s pioneering method of “playing the edge,” most students then encounter a yoga teacher leading a class in a certain way. Ideally, students will feel sufficiently empowered and self-respecting to ignore a teacher’s instruction if it goes against the student’s intention or does not feel right, but do not count on it. Problems arise when the teacher is ill-informed yet confidently giving guidance that fails to address the risk issues and contra-indications for any given asana and any given student condition. Yoga teachers should only teach what they know, and that knowledge should include the basic bio–mechanics of every asana they teach and the kinesiology of movement in every transition between asanas. They should also have extensive practice in learning how to observe students in asanas and what modifications are appropriate for each unique student in any given asana. Bringing this knowledge and set of skills together, teachers should craft and teach classes in which asanas are sequenced in an informed manner, not based on whim, random creativity or a universal template.

While yoga is in part about overcoming the ego and thereby opening to clearer awareness, it is important to appreciate that most yoga teachers and students have quite intact egos that are very much influenced by things such as popular culture, peer pressure and habits of thought. This underlines the importance of encouraging students to stay attuned to the breath as the essential barometer for what is happening in the practice, enabling even the newest student (and most experienced teacher) to explore in ways that allow the practice to be done safely and sustainably for one’s entire life.

Keep breathing, pay attention, and yoga will not wreck your body!

Yoga teacher Mark Stephens is the author of Teaching Yoga: Essential Foundations and Techniques (2010). His forthcoming book, Yoga Sequencing: Designing Transformative Yoga Classes, is due out this Fall from North Atlantic Books. Stephens lives and teaches in Santa Cruz, California. To learn more, please visit his website here.