Vedantaanga

Yoga is anabolic which conserve energy / Exercise is catabolic which is capable of breaking down the energy. Yoga practices slow dynamic movements / Exercise involves rapid forceful movements. Yoga practices reduced muscle tension, progressive movements / Exercise involves increased muscle tension.

When we relax, the flow of blood increases around our body giving us more energy. It helps us to have a calmer and clearer mind which aids positive thinking, concentration, memory and decision making. Relaxation slows our heart rate, reduces our blood pressure and relieves tension.

Patanjali explains that the control of prana is the regulation of inhalation and exhalation. This is accomplished by eliminating the pause between inhalation and exhalation, or by expanding the pause through retention. Then, by regulating the breath, the heart and the vagus nerve are controlled. The refinement and control of the breath affect the function of the vagus nerve, which in turn affects heart rate.

The science of pranayama is thus intimately connected with the autonomic nervous system and brings its functions under conscious control through the mastery of the breath, which requires taking conscious control of the diaphragm.

It is all about our Nervous system,

We have 2 main nervous system Central NS (brain and spine) and Peripheral Nervous S.

The autonomic nervous system is the part of the peripheral nervous system that regulates processes in our body which are not normally under our voluntary control, such as secretion by the digestive organs, the beating of the heart, and the movement of the diaphragm and other muscles that control intrathoracic pressure and therefore the flow of air into and out of the lungs.

Autonomic NS is divided into 2
Sympathetic NS and Parasympathetic NS.

The sympathetic side of the system is the one that produces the fright, fight and flight reaction. Basically, when we find ourselves in a life threatening situation, we get a flood of hormones that make us ready for anything. Our heart rate rises, our blood pressure goes up, our muscles are alert and our senses are heightened. In other words our body is primed to fight, or run, for our life.

Fear is not the only thing that stimulates the sympathetic nervous system – any form of stress on the body will have the same effect. Anxiety, bereavement, lack of sleep, relationship worries, money trouble, any form of illness, over training and pressure at work are just a few of the things that will increase activity in the sympathetic nervous system. Sadly, few of us live lives free of stress, so most of us have times in our lives when our sympathetic nervous system is highly active.

On the other side of the coin is the parasympathetic nervous system. When the parasympathetic system is stimulated muscles become less tense while the heart rate and blood pressure lower. The parasympathetic system cancels out the sympathetic system and has a calming effect on the body. 

Ideally, these two systems balance each other so that for every fight and flight moment there is a calming, settling time afterwards and the body comes back into equilibrium. Unfortunately, modern life with its stresses and pressure has a tendency to cause a lot more ‘fight and flight response’ with not much calming to balance us. This results in a gradual dominance of the sympathetic over the parasympathetic with resulting health issues like raised blood pressure, raised heart rate, increased muscle tension, digestive problems, headaches and poor sleep patterns.

The good news is that yoga stimulates the parasympathetic, or calming, side of the equation. It does this through breath control in your āsana practice, during specific breathing exercises, or Prānāyāma, and when you meditate. All of these yoga practices have been been shown to reduce blood pressure and heart rate. So, when you do yoga you are stimulating your parasympathetic system and as a result you will feel calmer, less stressed and sleep better.

Sources: sally schofield, Swami Rama,

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