Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 170

Any discussion of these issues must begin with definitions of terminology.⁷ Physical activity has traditionally been defined as any bodily movement produced by contraction of skeletal muscle that significantly increases energy expenditure, although the intensity and duration can vary substantially. This activity may be performed during leisure or occupational hours, and surveys of older adult should capture both paid and unpaid (volunteer) work. Exercise is a subcategory of leisure‐time physical activity in which planned, structured, repetitive bodily movements are performed, with or without the explicit intent of improving one or more components of physical fitness: aerobic capacity, muscle strength power and endurance, balance, coordination, and flexibility.

Recently, efforts have been focused on merging these formerly distinct entities of structured exercise and physical activity to promote ‘lifestyle integration’ of exercise as a means to enhance long‐term adherence. For example, taking the stairs instead of the elevator, standing on one leg while doing the dishes, or slowly standing and sitting without use of the arms represent ways of incorporating aerobic, balance, and strengthening exercises, respectively, into everyday activities. Current investigations are exploring whether such prescriptive techniques are superior to standard approaches for promoting behavioural change and targeted clinical outcomes such as falls in older adults, for which there is some support in the literature.⁸

Physical fitness, by contrast to the behaviours defined above, is defined as a set of attributes that contribute to the ability to perform physical work (e.g., cardiorespiratory endurance, muscle function, balance, flexibility, and body composition) or influence health status. Metabolic fitness has been advanced more recently as a term that encompasses a range of biologically important traits (increased insulin sensitivity, lipoprotein lipase activity, endothelial cell reactivity, heart rate variability, etc.) that may contribute to health status but do not directly affect exercise capacity. Both genetic predisposition and lifestyle factors contribute to physical and metabolic fitness and the extent to which they are modifiable with exercise training.