ABSTRACT

Importance of Fitness ................................................................... 113 5.5 Conclusions................................................................................................. 115 References ............................................................................................. 116

The purpose of this chapter is to review the research literature, examining and analyzing gender differences with respect to the amounts and types of physical activity needed to decrease morbidity and to promote health and independence in older adults. In epidemiological studies, the dose of physical activity required for beneficial effects has been assessed in terms of the total energy expenditure, the duration or energy expenditure of physical activities termed

exercise,

or the fitness levels achieved. The terms

physical activity, exercise,

and

physical fitness

have distinct definitions, and their differences may have distinct effects on outcome measures as well. Physical activity is defined as any bodily movement produced by skeletal muscle that results in energy expenditure. Exercise, a type of physical activity, is planned, structured, and repetitive bodily movement undertaken to improve or maintain one or more components of physical fitness. Physical fitness is a set of attributes that people have or achieve relating to their ability to perform physical activity. The majority of the literature has focused on physical activity measurements (using questionnaires to accommodate large surveys) and the amounts and types of physical activity needed to prevent disease and promote health. Whether the physical activity is classified as exercise is determined by the quantity or intensity of physical activity, or is reflected in the measurement of physical fitness levels.