This book helps to observe and find out the reality of factors which are creative causes and effective in generating, retaining & enhancing the energy and power in human body to perform various types of physical work and activities, particularly in sports. Bio-energy deals with various aspects of energy provided within the biological metabolic reactions creating output in human resource in forms like speed, strength and endurance of aerobic and anaerobic components of energy. Energy productivity is a biological and natural process in the human body which may deviate according to variation in age, nutrition, psychological activities and psychological conditions. The important aspects to be emphasized in order to achieve high level of performance is physiological development. Since what makes an individual difference from the other, depends upon the organism with respect to circulatory, respiratory, metabolic, neurological, temperature regulating functions, motar components and variables of physical activities. Physical education acts as intermediary between health and fitness. The degree of fitness depends on the individual's state of health formed by present and past activities.