For thousands of years yogis preserved and carefully guarded the knowledge of the inner and outer workings of a human being, very cautiously revealing the technology, selectively passing it down verbally from Master to chosen disciple. They were selective because knowledge gives power, and power can corrupt. Kundalini Yoga was always kept very secret. It was never taught publicly until 1969, When Yogi Bhajan challenged the ages-old tradition of secrecy.
The word kundalini literally means "the curl of the lock of hair of the beloved." It is a metaphor, a poetic way of describing the flow of energy and consciousness which already exists within each one of us. The practices enable you to merge with or "yoke" with the universal Self. This merging of individual consciousness with universal consciousness creates a "divine union" called "yoga." The technology of Kundalini Yoga applies its science to our bodies and minds, and is aimed at spirit which has no boundaries, no discrimination. Therefore it is for everyone. It is universal and nondenominational.
Kundalini Yoga deals specifically with the most powerful thing in the universe, the basic life energy, prana. Prana is the sub-atomic energy, the life force. Kundalini Yoga is the path of discovery of the source of the prana in us and teaches us how to use it. In Kundalini Yoga we harness the mental, physical and nervous energies of the body and puts them under the domain of the will, which is the instrument of the soul. Kundalini Yoga perfects the finite life while connecting it to the infinite experience.
The practice of Kundalini Yoga also balances the glandular system, strengthens the nervous system and enables us to harness the energy of the mind and the emotions, so we can be in control of ourselves, rather than being controlled by our thoughts and feelings. Of all the technology and wisdom that Yogi Bhajan could have taught from his vast storehouse of mastery, he chose to teach Kundalini Yoga because it is so effective, comprehensive, and so "do-able."
No matter what we achieve, what success in the world we have, it ends up being hollow unless we fulfill the soul's yearning to bring higher consciousness into our daily lives. Kundalini Yoga is much more than just a system of physical exercise. It is a dynamic, powerful, tool for expanding awareness. Approach it with respect, with reverence, and openness.
Excerpt taken from 3HO Web Site:
Kundalini yoga is based on kriyas, or specially formulated sets of exercises. This allows you to target specific benefits and work on exactly those aspects of yourself that need work at the current time. Any amount of time spent practicing - whether three minutes or an hour a day - produces significant benefits, and in turn, motivate individuals to dedicate more time to its practice.
Practicing Kundalini Yoga keeps the body in shape and trains the mind to be strong and flexible in the face of stress and change. It increases oxygen capacity, boosts blood flow, balances the glandular system, strengthens the nervous system, and reduces stress-induced toxins such as adrenaline and cortisol. The effect is a heightened self-awareness and vitality that allows you to harness mental and emotional energy. Individuals feel more in control of themselves, with enhanced peace of mind, concentration, and a deep inner calm and self-confidence. No matter what someone's age or physical capacity is, Kundalini yoga and meditation can have immediate benefits.
[Excerpt from “KUNDALINI YOGA: The Flow of Eternal Power An Easy Guide to the Yoga of Awareness – As Taught by Yogi Bhajan, Ph.D”, written by Shakti Parwha Kaur Khalsa.]