The Most Dangerous Word in Exercise

A Hall of Fame NFL running back I knew once suffered a knee sprain. His trainers, some of the best in the world, set up a training protocol that involved aggressive strengthening for the quadriceps muscle, coupled with increasing the flexibility of the hamstring muscle. The result: The quadriceps remained tight and explosively powerful, but the hamstring was comparatively flexible. Weeks later he was back on the field for the first game since his injury. There was considerable buzz and anticipation: How would he perform? Then, on his first play, on national television, in super slow-mo, he took the ball and exploded out of the backfield, powerful legs churning. No one touched him as he reached peak power and stride. What happened next is that his flexible hamstrings couldn’t counteract their opposition, so his knee hyperextended, tearing his hamstring, and he went down like a sack of bricks. Across America, people cringed in empathetic agony, but hardly anyone got the message. His problem had to do with flexibility: too much of it!

Okay, so most of us are not pro football players, yet the point is the same. In fact, it may well be more relevant to many of us. Beyond a certain age, most of us are training for life, more specifically quality of life. That quality of life is measured physically by our functional capacity to do all the stuff we like to do—like taking a hike in the mountains, dancing at weddings, and picking up kids and grandkids and pets. These critical life movements each require a specific functional range of motion for each joint involved. Too little range of motion, and we can’t do what we want without straining. Too much range of motion, and we too are likely to go down like a sack of bricks.

This is why I don’t like to use the word flexibility. The culture of the word implies that more is better, and that is simply not true. A healthy goal is not flexibility but rather joint stability with a sufficient, functional range of motion. It sounds complicated, and is—but also is not.

That brings me to yoga, which I take with at least a grain of Sanskrit.

My job as a medical exercise specialist is to assess people’s medical conditions, their co-morbidities, and their contraindications, as they relate to exercise programs. Co-morbidity simply means you have more than one medical thing going on at a time. A contraindication refers to a movement or activity that would be bad for that condition. Things get especially tricky when you have contraindications within co-morbidities, meaning that what might be good for one condition could be disastrous for another.

There are so many yoga poses and medical contraindications that it would take a book address them. But let me put it this way: I get a lot of “rehab” business as a result of yoga. The basic problem is that “progress” tends to mean getting deeper into a pose—increasing “flexibility” by creating an increasingly dubious, if not actually dangerous, range of motion. When instructed to breathe and sink deeper into a pose, the first question to ask your instructor is “Why?” Is there a functional good beyond achieving the pose itself? If you’re young, you may not have to pay a price for being overly flexible for many years. If you’re older, paying the price can happen fast.

Let’s say you join a yoga class because your primary goal is to loosen your psoas muscles and strengthen your core. These are pretty common issues, and you inform your instructor of them before class. You also mention that you have spondylolisthesis. Maybe your instructor doesn’t know what that is (an anterior slippage of a lumbar vertebra), or does and figures the core and psoas work will ultimately help support the spine, so off you go. The contraindication here is that even the most basic back bend (think “upward dog”) for someone with spondylolisthesis creates what is commonly known as “the watermelon seed” effect, exacerbating the anterior slippage of the affected vertebra. You had the best of intentions, but now you are sidelined and injured.

My advice is to let your yoga instructor know your various conditions and ask her if she is comfortable with accommodating you. If her eyes glaze over, move on down the road. There are many, many ways to become and remain functionally fit—and they each have pros and cons. But please consider evaluating every program using a very simple measure: Will this movement be useful for the rest of my life?