The first chapter of this manual discusses the impact physical activity has on the growth and development of youngsters. It offers a rationale for including physical education in the school curriculum. Guidelines for exercising children safely are offered, including a section on weight training for children. Chapter 2 includes the Physical Best fitness test, as well as guidelines for testing, measuring, and evaluating physical fitness. A discussion explains efficient test administration procedures and planning for fitness testing in the school setting. The third chapter focuses on special populations including obese and handicapped children. A number of suggestions for modifying activities to meet the needs of special populations include consideration of the problems of asthmatic youngsters. Chapter 4 looks at fitness, nutrition, substance abuse, and the role they play in developing wellness in children. Emphasis is placed on developing positive attitudes. The fifth chapter offers many activities for developing fitness in children of all ages. Effectively teaching a class in the fitness environment is discussed as is the importance of understanding the role of fitness in the total physical education lesson. (JD)