Showing posts with label baroreceptors. Show all posts
Showing posts with label baroreceptors. Show all posts

Monday, May 21, 2012

Getting Comfortable in Forward Bends

by Nina

I have always known that seated forward bends are considered quieting poses, but it wasn't until I interviewed Shari (see Talking About Baroreceptors and Yoga) about baroreceptors that I discovered that forward bends are quieting for the same reason that inverted poses are calming: pressure on the baroreceptors causes your body to lower your blood pressure and reduce your stress hormones. No wonder three minutes in a forward bend seems to turn off the noise in my head and put me in a relaxed, almost dreamy state. But this got me curious because you're not exactly upside down in a forward bend, so I asked Baxter if he knew why forward bends had the same effect as inversions (I'm like that about yoga, I always want to know why!). Here's what he said:

Regarding the beneficial effect of seated forward folds on lowering blood pressure, I would hypothesize that the fold brings enough pressure onto the abdominal area to place pressure on the main blood vessel in the belly, the abdominal aorta. If this caused a temporary narrowing in the vessel, this could create a back pressure up to the baroreceptors in the neck and aortic arch. This would have the same effect as inversions.

By now you may be reading this and thinking, "That's fine for you to say, but I hate forward bends.  Just the thought of doing them makes me feel cranky, not relaxed." Yes, I realize that I'm one of the lucky few who is flexible enough to be comfortable in forward bends. And I do know that a large number of people, especially those with tight hamstrings, are, shall we say, quite the opposite of comfortable in forward bends. For those people, discomfort in the pose pretty much negates the soothing effects because being physically uncomfortable tends to irritate the nervous system.

But does that mean you have to miss out entirely on the blissful feeling I've just described? Definitely not! Because in today's post I'm going to present two different ways to prop your forward bends to take remove the yuck and bring on the bliss.

The first way is to place a round bolster or a very thick blanket roll behind the thigh of your straight leg or behind both legs if you are doing Paschimottanasana (as shown in the photo below). With the bolster behind your thigh, you knee or knees will be bent and supported.
Bend from your hips to come into the forward bend and then slowly round your back into a gentle curve. Baxter is someone who has very tight hamstrings and normally doesn't enjoy forward bends, but just look how comfy he looks in these photographs!
Stay in the pose at least three minutes (I've found it takes that long for the pose to work its magic). Whhen you are ready to come out of the pose, come out very slowly, rolling up to an upright position.

And if that propping doesn't work for you, I've got another trick up my sleeve. In the second version of a supported forward bend, you use a bench or chair on which to rest your arms and head. Position the chair over your straight leg (or legs), far enough away so you can keep your spine long and straight when you come into the forward bend. If the bench or chair isn't high enough for you to easily reach, add folded blankets or towels to increase the height. To come into the pose, bend from your hip joints, keeping your spine straight and long (in this version you do not round your back). Place your folded arms on the chair or bench, and rest your head on your hands. If possible, catch your forehead skin on your hands and tug it gently down toward your eyebrows.
Again, stay in the pose at least three minutes. When you are ready to come out of the pose, come out very slowly, using your hands to press yourself into an upright position.

I often teach this second version of the pose, and I'm always so pleased to see almost everyone in the class come out of the pose with a calm, relaxed expression on their faces! I'd love to hear how it feels to you!

For cautions for these forward bends (and forward bends in general), see Which Forward Bends Are Safe?



Wednesday, May 16, 2012

Blood Pressure: Talking about Baroreceptors and Yoga

by Shari and Nina 

Nina: Yesterday, Baxter gave us a little background on blood pressure (see So, what is blood pressure, anyway?). I thought today you could talk a bit more about the relationship between blood pressure and yoga.

Shari: First some more background! Of particular importance is the effect of our baroreceptors on blood pressure. Baroreceptors are stretch receptors that found in the major arteries, and they are activated when our arteries are over- or under-pressured by blood flow. This in turn changes our heart rate and arterial diameters. Baroreceptors are found abundantly in the carotid sinuses, the carotid arteries of the neck and the aortic arch of the heart.

Carotid Sinuses (Carotid Arteries of the Neck)

Aortic Arch of the Heart
When there is an increase in arterial pressure because of increased blood flow, vasodilation occurs and the heart rate will then drop. This causes a decrease in cardiac contraction and in turn causes a decrease in blood pressure.

Nina: For all of us overstressed folks, decreasing blood pressure is a good thing. And I’m betting yoga can help with this....

Shari: Absolutely. Research has shown that both forward bends and inversions affect the cardiac baroreceptors, ultimately causing a decrease in blood pressure and heart rate! Inversions and forward bends also increase baroreceptor sensitivity toward the fluid dynamic changes. So both forward bends and supported inversions are both recommended for reducing blood pressure.

Nina: That explains why both forward bends and supported inversions are considered calming poses. I certainly use both in my home practice for stress reduction. Do you have any favorite poses for lowering blood pressure?

Shari: I like supported Setubanda Sarvangasana (Bridge pose, with straight legs), perhaps with a head wrap. I also like Viparita Karani (Legs Up the Wall pose) with a head wrap. When the going gets rough, these are my “comfort poses.”

Nina: I also love Legs Up the Wall pose. And supported Child's pose is a good example of a forward bend that is very comforting—just thinking about it makes me relax. And we’ll definitely have to talk about the head wrap sometime soon!


Wednesday, November 23, 2011

Just in Time for the Holidays: Inverted Poses

by Nina

In my original post about the relaxation response and yoga (see here), I mentioned that inverted yoga poses are one of the many ways you can trigger the relaxation response. Inverted poses are my personal go-to stress busters of choice, and if I could get my hands on Paul Weston (see here), I’d certainly teach him one or more of these amazing poses. So today I’m going to explain what I mean by “inverted poses,” and I’ll also provide some scientific background on them because understanding why these poses work can help you get the most out of them. Okay, here goes:

Any yoga pose where your heart is above your head is considered to be an inversion. Inverted yoga poses include full inversions, such as Headstand and Shoulderstand, where your heart is directly over your head and the rest of your body is also fully inverted. Also included as inverted poses are partial inversions, such as Downward-Facing Dog pose and Standing Forward Bend, where your heart is less directly over your head and your legs are either not fully and not at all inverted.
Standing Forward Bend from Yoga: The Poetry of the Body
The reason these poses trigger the relaxation response turns to be related to the mechanisms that control your heart rate and blood pressure. The nerves that control your heart rate and blood pressure are regulated through pressure sensors called baroreceptors. Your baroreceptors are located in the wall of each internal carotid artery at your carotid sinus (the arteries on each side of your neck that carry blood from your heart to your brain) and in the wall of your aortic arch (just above your heart). These baroreceptors detect any changes in your blood pressure, stretching when blood pressure is high and shrinking when blood pressure is low.

If your baroreceptors detect a fall in your blood pressure, they send signals via your nerves to increase your heart rate, constrict your blood vessels to raise your blood pressure, and switch your nervous system to fight or flight mode. Likewise, if your baroreceptors detect abnormally elevated blood pressure, they send signals to slow your heart rate, relax your blood vessels to lower your blood pressure, and switch your nervous system to relaxation mode.

In an inverted pose, your heart is higher than your head, the opposite of its position when you are upright. With your heart higher than your head, gravity causes more blood to flow in the direction of your head, creating more pressure than usual on your carotid sinus and aortic arch. As the arterial pressure is increased, your baroreceptors are stretched and signals are transmitted to your central nervous system as if your blood pressure was high throughout your body. Feedback signals are then sent back to your body to reduce the arterial pressure, slowing your heart rate, relaxing your blood vessels, and releasing hormones that decrease adrenaline production. This automatically switches your body to relaxation mode.

In addition, inverted or partially inverted poses where your neck is flexed (that is, your chin is pointing toward your chest), as in Shoulderstand, Plow pose, or Bridge pose, puts additional pressure on your carotid sinus (the arteries on each side of your neck that carry blood from your heart to your brain). This added stimulation of your baroreceptors may enhance the calming effects of the inversion.

How simple is that? As long as you are warm, quiet, and comfortable in the inverted pose, all you have to do is let pose work its magic! Naturally, supported versions of the poses (such as Shoulderstand with a chair or Bridge pose on blankets) are more relaxing than straight versions of poses in which you must support yourself, so if you’re practicing inversions for stress reduction, choose the supported versions.

In the coming weeks, I’ll provide details about the various inverted poses, but until then, the following is classic sequence of calming inversions. You can do any or all of these poses, but if you do more than one, I recommend doing them in the order shown below.

1.    Downward-Facing Dog pose, with your head resting on a block or folded blankets (1 to 3 minutes)
2.    Standing Forward Bend, with your head resting on a block or with folded arms and head resting on a chair seat (1 to 3 minutes)
3.    Wide-Legged Standing Forward Bend (Prasarita Padottansansa), with your head resting on the ground, a block, or the seat of a chair (1 to 3 minutes)
4.    Headstand (3 to 10 minutes)
5.    Shoulderstand, with a chair (3 to 10 minutes)
6.    Half Plow pose, with your legs supported by a chair seat (1 to 3 minutes)
7.    Supported Bridge pose, with your shoulders and head resting on the floor, your torso and legs supported by blankets or bolsters (5 to 15 minutes or longer)
8.    Legs up the Wall pose (Viparita Karani) with your pelvis supported with a bolster or blankets (5 to 15 minutes)

I’ve taught this sequence many times, and there are always people in each class who have difficulty with one or more of these poses. So I always teach a non-classic pose as well, Easy Inverted Pose (see here), because this is one pose almost everyone can do. Use this as a substitute for Shoulderstand, Plow pose, Bridge pose, or Legs Up the Wall pose, or just use it on its own.

Caution: Inverted poses may be unsafe for those with certain medical conditions (see here).