Continuing from our last post…
There are two main reasons we don’t subscribe to the notion that inversions reverse the effects of gravity (in addition to a host of other purported benefits):
Reason #1) Homeostasis, as applied to biology, is the physical body’s way of preserving an internal state of balance. An example of homeostasis is thermoregulation or the maintenance of body temperature: (from another site) special sensors sense the temperature of the blood and send the information to a part of the brain known as the hypothalamus. The hypothalamus “knows” that the proper temperature should be about 98.6°F. If the sensed temperature is significantly higher, the hypothalamus sends signals to the sweat glands of the skin and the surface blood vessels. The sweat glands produce sweat evaporates and the blood vessels dilateallowing more heat loss through the skin. In contrast, if the sensed temperature is low, the hypothalamus sends signals to muscles to cause shiveringand the surface blood vessels to constrict.
So this basic concept of our body, keeping a constant and certain standard in many biological functions is a key principle to our survival. Let’s think about that. Will putting your legs up the wall really make it easier on your heart to pump blood to extremities? No. It will do what it has to do to make sure our extremities don’t lose circulation, as it successfully does all the time. Just like going upside down won’t stop the menstrual flow or reverse it (another controversial issue in the female yoga practice). Being upside down also won’t send more blood to the brain, not if your blood brain barrier is working. Will being upside down help with lymph flow? Maybe, sure, why not? All movement keeps lymph flow at an optimal level, so yeah. Coincidentally, the sometimes not so pleasant sensation of “blood rushing to your head,” is actually not blood. It’s a fluid from the vestibular sacs in your inner ear. JUST SO YOU KNOW, blood is inside of vessels and has its own pump system for a reason; it doesn’t just pool where gravity’s pull is most evident.
Circulation to the brain, which is another assumed benefit of inverted postures, does not increase. If you were never upside down in your whole life you probably would still have the brain function you need. Optimal brain function is influenced by other factors.
Bottom line: Your body will (for most of us) fight to maintain a standard of function despite your relationship with gravity, even if that relationship varies. So going upside down does not necessarily combat gravitational forces, especially given the fact that we have a particular and active relationship with gravity most of the time. Any little bit of time we spend upside down won’t be enough to permanently change anything. Even if we spent 50% of our time “upside down,” that condition might become the new “right side up” to certain internal structures, thus sabotaging the ideas put forth in yoga classes. Some part of you will always be subject to gravity at all times! We simply do not have the scientific data of enough people spending enough time in these poses to create a real picture of what the effects on the physical body would be.
(Before people start screaming, are there good reasons for ever being upside down? Yeah, sure! But that post is coming a little later.)
Reason #2) Belief in the inherent value of yoga postures is a slippery slope to an unjustifiable dogma. You know what we mean. You hear wanna-be axioms such as; “Twists cleanse your organs,” “Being upside down increases brain activity,” “Doing shoulder stand is good for the thyroid,” “Belly breathing is the most beneficial way to breathe,” etc. By now you know us well enough to know that we don’t agree with any of that. This disagreement is not evidence of our contrarian nature. It is evidence of the fact that we are critical thinkers who don’t take information for granted without exploring it in our own bodies or doing research in the academic/scientific realm.
What this means: like many of our beloved teachers, we do not subscribe to a system of yoga. We do not believe as an absolute truth that certain yoga poses themselves embody any inherent or immediate benefits or harm, as applied to the entire human population.
Questions or comments about that? Let us know below!