Kundalini Yoga for Youth and Joy by Yogi Bhajan will leave you feeling healthy and energetic, with renewed enthusiasm for life. A body which is strong, flexible and radiant need not be young in years, as a stiff, slow, fragile body need not be advanced in age. An aging body is a body out of tune, out of shape and most often is the result of the inability to handle mental and physical stresses in the environment.