Some time back a new energy form found in the human body, which is not electrical energy, not magnetic energy and not the heat, but it is biological in nature. Hence it is concluded as Bioplasmic energy in 1935 by Dr. Harold Burr- 1935. This was later on experimented and supported by a lab technician, Kirlian. According to National Institute of Health Scientists in 1994, this is called as Biofield. This is composed of both electro-magnetic energy and hypothetical energy. This is also termed as human energy field or Aura. Vedic cultures of India said this as Prana, Chinese culture termed it as Chi or Qi.
Bioplasmic energy mix with free electrons and quantum energy from the inhaled Oxygen and manifests as ionized atomic particles in the body. These particles emit a strange, complex pattern of light that is bioluminescence about 4-5 inches above the physical body. This can be captured by rare equipment like Gas discharge Visualization, Acugraph, Aura machine etc., These are truly beyond the modern medical diagnostic tools.
Hence breathing and its manipulation is important to have an equal proportion of Prana around the body. This is how the Pranayama was brought to the world from ancient days. Pranayama means manipulation of breath or life force. Breathing exercise is the modern term for few techniques for the respiratory system. If we extend the awareness towards ancient texts, few techniques like; Nadishodhana (alternate nostril breathing) which switches the awareness towards the autonomic nervous system. Eg: Swami Rama could slow down his Heart for a while and bring to normal voluntarily. Some like Sheetali (Tongue breathing), cools down the body temperature and some like Bhramari (Honey bee sound) smoothens the brain activity.