Physical activity and movement in children: its consequences for growth and development.

The value of physical activity to health and fitness and normal growth and development is undisputed. In contrast, lack of exercise or excesses in physical activity can be harmful to the growth and development process. Normal physical maturation represents a succession of events which appear in the same sequence in all individuals but vary in both starting point and speed of occurrence. It is often difficult to distinguish the effects of regular physical activity upon fitness from the changes associated with growth and maturation. An integral component of the relationship between health and fitness is body composition. Maintenance of a desirable body composition is an integral component in health status and in the evaluation of health, fitness and physical performance of individuals. Traditionally, discussions that have considered the benefits of regular physical activity have referenced cardiorespiratory and other components of physical fitness such as muscular strength and endurance. More recently, body composition has received considerable attention with numerous individuals of all ages preoccupied with body characteristics such as body fat and muscularity. Less recognition has been given to the role that exercise plays in the maintenance of skeletal health and the potential benefits to be gained by this component of body composition. This is gradually changing with the knowledge that osteoporosis is mediated by nutritional, physical activity and hormonal influences and that inappropriate physical activity can be potentially hazardous to the immature and mature skeleton. Regular physical activity that provides an appropriate weight bearing stimulus is critical for the maintenance of desirable body composition including normal skeletal health, irrespective of age or sex. Benefits derived for body composition are equally important to personal health as the development of other components of fitness.