Pranayam and cardio pulmonary fitness

The heart supplies blood to all the organs in the body, it pumps out blood via blood vessels, once the blood reaches these places it empties its package of nutrients and the needs to get back for a refill of nutrients! there are veins that carry blood back to th heart.

The blood in the feet, calves and thighs is far away from the heart how does it get back?

This is where a simple arrangement of valves and respiratory or breathing movements comes to work and pushes or 'sucks' the blood back to the heart(venous return).

The calf muscle and the thigh muscles play the important roles of a pump squeezing the blood upwards as they contract, and there are, located in the veins of the calves and the thighs a number of valves that allow blood to flow only up, towards the heart, for example 1 valve is in the calf next one higher up next still higher up in the thigh, the valve, opening only when the blood is flowing up to the heart and then closing when the blood 'falls' back when the muscles are momentarily relaxing! Thus the blood flows only up.

In this way the blood reaches the abdominal cavity.

When we exhale the lungs constrict, creating a vacuum or negative pressure below in the abdominal cavity, this vacuum in the abdominal cavity sucks up the blood from the thighs and the blood travels upwards. The blood does not flow back into the lower extremities as the valves mentioned earlier close upon the back flow of blood.

After exhalation we inhale this expands the lungs which in turn increase in size and push down upon the abdominal cavity squeezing it, the pressure within the abdominal cavity rises the blood rushes up to the thoracic cavity (region of lesser pressure) and, finally into the heart!

This principle of pressure changes during respiratory movements is used in the exercise of PRANAYAM.

This activity deals with breathing exercises which aid venous return thus improving cardio-pulmonary fitness, reducing cardiac workload so improving the efficiency of the heart as a pump. If done correctly it will help reducing risk of cardiac ailments and will improve cardiovascular fitness.