To clarify the science of yoga and make it accessible to the majority of seekers, Seami Vishnu-devananda extracted its essence and presented yoga in five universal principles for physical and mental health as well as spiritual growth.These five principles constitute the essence of the teachings of the Sivananda Yoga Vedanta Centres.Proper Exercise(Asanas). Our physical body is meant to move and exercise. If our lifestyle does not provide natural motion of muscles and joints,then disease and great discomfort will ensue with time. Proper exercise should be pleasant to the practitioner while beneficial to the body,mind and soul.
Proper Breathing(Pranayama)

Yoga teaches us how to use the lungs to their maximum capacity and how to control the breath. Proper breathing should be deep, slow and rhythmical. This increases vitality and mental clarity.
Proper Relaxation(Savasana)

Long before the invention of cars, planes, telephones, computers, freeways and other modern triggers of stress, the rishis(Sages or seers) and yogis of yore devised very powerful techniques of deep relaxation.