Figure 4 —

Health benefits of exercise are determined, in part, by the energy expenditure associated with physical activity. Both too much (excessive) and too little (sedentarism) exercise can impair health. As shown, the range of healthy exercise is narrower in the child with chronic disease or disability. CPET and physical fitness testing must be designed to identify biological mechanisms that can be translated into finding the mode, frequency, duration, and intensity of exercise that can benefit health during critical periods of growth. CPET indicates cardiopulmonary exercise testing.