Pranayamam

Pranayamam is essentially a respiration control
Letting out air is called "Rechaka"; Taking in air is called "Puraka" and holding air inside is called "Kumbaka"
Pranayamam has high place in all vedic rites and is used as a purificatory process. Sages like yagnavalkya, bhodayana have elaborated the greatness of Pranayamam. Manu says that the practice of pranayamam correctly (as detailed earlier) with Vyahrithis, gayathri and gayathri siras, is itself a tapas (austerityor penance) of high order. It purifies the practitioner and purges him of all sins.
Pranayama is used by natural therapists for curing various ailments. According to them, pranayamam helps to control the five basic elements (Fire, etc.) and thus the Bio-electricity.Keeping together (or making contact) of the thumb and first finger of the left hand with the palm facing skywards is also significant. This is known as "meditation mudra". The palm of hand and tips of fingers have chakras. These are capable of absorbing life energy from surroundings. This also helps in respiratory control during pranayamam. Left hand is also known as "amrita hasta" that is a hand with nectar.
Advantages are Absorb, digest and distribute vital energy all over the body. This results in improved health, blood circulation, digestion and other body activities. This also helps to improve memory,sharpness of intellect, mind control, self confidence and many other benefits.
Preserve the functioning of the physical body.
According to our sages, the chakras not only help to maintain a healthy physical body but also help to mould the mind and character of the person. Activation of some chakras result in development of certain pshychic faculties or special powers.