Introduction
Body size, proportions, physique and composition are factors which influence physical fitness. Historically, stature and weight, both indicators of overall body size, have been used extensively with age and sex in efforts to identify some optimum combination of these variables for classifying children, youth and young adults in a variety of physical activities. Skinfold thicknesses are routinely used to estimate body composition, and are now included in physical fitness test batteries. Body size, specifically body weight, is the standard frame of reference for expressing physiological parameters, such as VO2max. Hence, anthropometry is central to the study of physical fitness in the general population and in special populations, including elite athletes and those chronically stressed by under nutrition.
The present chapter considers the anthropometric correlates of physical fitness, and builds upon an earlier review (Malina, 1975). It is limited largely to samples of well-nourished children and youth, but also considers related data for disadvantaged and undernourished samples. Fatness as a factor affecting fitness is considered separately, as is the possibility of an optimal body size for physical fitness and performance.
Fitness and performance
Performance is viewed in the context of standardized strength and motor tasks, which were historically defined as the components of physical fitness. More recently, however, the definition of fitness has taken a health-related perspective, in which fitness is operationalized as cardio-respiratory endurance, abdominal muscular strength and endurance, lower back flexibility, and fatness (Malina, 1991). Hence, the terms health-related fitness and motor fitness are used. The concept of fitness continues to evolve as apparent in the morphological, muscular, motor, cardio-respiratory and metabolic components of physical and physiological fitness offered by Bouchard & Shephard (1993).