The self-perpetuating human body can be considered as a type of battery composed of three vital parts.

1. Structure: The cells and the organs, bones, muscle, skin layers, blood vessels, nerves and other physical structures that they form.
2. 2. Liquid: The intra and inter-cellular liquids that play important roles in the generation of electrical energy.
3. Electrical charge: The charge responsible for activating the body and its structures. It is called the "life-force", life energy, spirit or electromagnetism. The Chinese refer to this as "chi".

Of the three components, the last – electrical charge is least understood, since it’s presence is not immediately obvious to naked eye. Electrical energy is detected only in a roundabout way, because it is most obvious when it is absent. If there is partial absence of energy in the body, weakness or disease invades. When there is total absence of vital energy, there is death. (cessation of heartbeat does not necessarily mean death, for many yogis have stopped their own heartbeat, yet remain alive because their bodies still hold vital energy.)

Exhaustion is a symptom of low energy levels. Anytime you use your body or your mind you lose energy. According to scientific studies, if you focus your eyes on an object for one minute it will take twenty minutes of rest to regain the amount of energy lost. Furthermore, studies have been done in which dying people have been put on a scale and weighted, at the point of death, there has been recorded a weight loss of six ounces, varying from person to person. It is believed that the six ounces weight loss reflects the weight of vital energy, which is material and measurable.

The aura or energy field around a person’s body has been known for many years, but it now has been proved to exist with the advent of Kirlian photography. A simple description of the aura suggests that it is made up of coloured flames of energy that are emitted from the human body. The colours of the aura have been determined to be reflective of health and energy levels. Light, clear colours indicate good health and high energy levels, whilst dark, heavy colours indicate disease.

Minute after minute, hour after hour, day after day we lose energy by body movements and mental activities. In time, if this constant loss of energy if not replenished, weakness and illness will follow.

Of course we also acquire vital energy too, through the food we eat, the air we breathe and cosmic radiation. We also require normal, restful sleep, which relaxes the acupoints of exit and entry and allows the universal energy to travel through the meridians and reach and recharge every cell in the body.

Another way we can increase our vital energy is by practising the internal art of Qigong and Tai Chi regularly.