Amrita 6: Asana through the ages - Magazine - Page 35
Take a Deep Breath
The functions of the diaphragm and how to strengthen it using headstand
HAVE YOU SEEN the Iyengar video where he inhales for about
50 seconds? Try it yourself and see how you get on. How did he
do it? Firstly he was using a partially closed glottis (Ujjayi breath)
to restrict the air flow, so effectively ‘thinning out’ his breath, a
bit like turning a running water tap to nearly closed. You may
think he must have increased his lung capacity, meaning his
lung size had increased. However, in general regular exercise
does not substantially change measures of pulmonary function
such as total lung capacity, the volume of air in the lungs after
taking the largest breath possible (TLC), and forced vital capacity, the amount of air able to be blown out after taking the largest
breath possible (FVC). Studies comparing TLC and FVC show
little difference between regular exercisers and non-exercisers.
What can be be altered is the volume of the thoracic cavity.
Air is drawn into the lungs when the pressure in the thoracic
cavity is less than the outside, atmospheric, air pressure. The
more the volume of the thoracic cavity increases, the greater
the pressure difference, and the more air is drawn in. There are
two ways to increase the volume of the thorax, or chest: Expand the chest size by engaging the intercostal muscles, and
by taking the diaphragm to the full limit of its descent. The
length and depth of breathing is dependent on how much the
diaphragm moves between a full inhalation and a full exhalation. In an average healthy adult this is between 3 to 5 centimetres, and in a well-conditioned adult it increases to as
much as 8 centimetres. Iyengar is essentially demonstrating a
well-conditioned and strong diaphragm, moving through its
full range of motion.
The native Americans saw the diaphragm as the horizon
between Heaven and Earth. With its central location in the
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body, dividing the thoracic and abdominal cavities, it is often
described as a ‘separating structure’. But we can also see it as
a connecting structure between the upper and lower body.
The diaphragm mediates between heaven and earth, between the mind and body. It does this through the breath.
When the breath and the diaphragm move freely, we experience a sense of wholeness, integration and lightness.
Why it’s important to have a strong diaphragm
The Respiratory Pump
The heart pumps blood through a network of arteries, arterioles and capillaries to supply oxygen and nutrients to every
cell in our body. Blood is then returned to the heart through
a system of veins. Blood is emptied from the veins into a
large vein known as the Vena Cava, which runs from the lower abdomen to the right atrium of the heart. During inspiration, the descending diaphragm compresses the abdominal
organs producing a positive intra-abdominal pressure. The
pressure in the thoracic cavity is negative, creating a pressure
gradient between the lower and upper parts of the vena
cava. This pulls blood towards the right atrium and plays a
key role in venous return.
In other words, the diaphragm is a membrane pump,
bringing blood back to the heart. When the diaphragm
pumps stronger, the venous return increases. Increased venous return increases the force of contraction of the heart
muscles, often described as the Frank-Starling law. An optimally functioning diaphragm is directly linked to good cardio-vascular function.
AMRITA Issue 6 / Spring 2021 33
