Physical Activity and Health
A Report of the Surgeon General of the United States:
The publication of the Surgeon General’s report titled “Physical Activity and Health” is a landmark in the history of muscle and exercise physiology and disciplines related to sports medicine, not only because it summarizes results of research from diverse fields, but also because the document serves as an articulation of public policy. The main message of this report is that Americans can substantially improve their health and quality of life by including moderate amounts of physical activity in their daily lives.
In 1994 the Office of the Surgeon General of the United States authorized the Centers for Disease Control and Prevention (CDC) to serve as the lead agency in preparing the first Surgeon General’s report on physical activity and health. The CDC was joined in the effort by the President’s Council on Physical Fitness and Sports (PCPFS), the Office of Public Health and Science, the Office of Disease Prevention at the National Institutes of Health (NIH), and several institutes from the NIH, including the National Heart, Lung, and Blood Institute; the National Institute of Child Health and Human Development; the National Institute of Diabetes and Digestive and Kidney Diseases; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases. In addition, the CDC’s efforts were buttressed by several nonfederal scholarly and professional organizations, including the American Alliance for Health, Physical Education, Recreation, and Dance (AAHPERD); the American College of Sports Medicine (ACSM); and the American Heart Association (AHA). Representatives of those organizations provided consultation throughout the development process.
The report is noteworthy in several respects. As previously stated, it recognized that physical activity is essential for the health and well-being of the general population, and it emphasized the importance of regular, moderate-intensity exercise as well as Vigorous activity to achieve and maintain cardiorespiratorv fitness. The report encourages people of all ages to include a minimum of 30 minutes of physical activity of moderate intensity (such as brisk walking) on most days. Further, the report was definite in recommending physical activity as a means to manage chronic diseases other than cardiovascular disease, such as diabetes, colon cancer, osteoa Arthritis, and osteoporosis. The Surgeon General’s report noted also that in addition to promoting muscle strength and minimizing injury due to falls in the aged, regular exercise may be important in relieving symptoms of depression and anxiety, thereby improving mood and promoting a sense of well-being.
The interim between publication of the third and fourth editions of Exercise Physiology was marked by publication of the Institute of Medicine’s report on dietary macronutrient consumption titled “Dietary Reference Intakes: Energy, Carbohydrate, Fiber, Fatty Acids, Cholesterol, Protein, and Amino Acids” (http://www.nap.edu/openbook.php?isbn=0309085373/). Contents of this report, generally referred to as the Macron utrient Report, are detailed in Chapter 28, but impact of this momentous report is detailed here.
In 2000 the NIH and Health Canada commissioned the National Academies of Science (NAS) to:
(1 )review the scientific literature regarding macronutrients (proteins, amino acids, phospholipids, cholesterol, complex carbohydrates, simple sugars, dietary fiber, energy intake, and energy expenditure) to determine the roles, if any, they play in health;
(2) review selected components of food that may influence the bioavailability of these compounds;
(3) develop estimates of dietary intake of these compounds that are compatible with good nutrition throughout the life span and that may decrease the risk of chronic disease determine the tolerable upper intake levels for each compound.
Through its ancillary organizational units, specifically the Food arid Nutrition Board of the Institute of Medicine (TOM), a panel of experts were convened to meet and author a technical report to provide guidance to health care professionals when making dietary recommendations. Because the possibilities for conflicts of interest and industrial espionage were rife, the NAS was commissioned to produce the Report under a federal statute dating from the U.S. Civil War; the NAS and its entities are immune from subpoena by all entities, including the U.S. Congress. The 2002 Macronutrient Report
follows similar reports released in 1974, 1980, and 1989 in which distinguished panels of the Food and Nutrition Board labored to define Recommended Daily Allowances (RDAs) of dietary macronutrients. Fundamental to work of the most recent panel authoring the Macronutrient Report was the decision to base daily dietary energy intake recommendations on energy expenditure. This approach became possible because of new doubly labeled water (DLW) isotope tracer technology so that energy expenditures of large numbers of people could be estimated with certainty. Those analyses revealed a wide range of energy expenditures by healthy adults, but the mean physical activity level (PAL) of those with stable body weights in the healthy range was 1.6, or 60% over basal. In terms of an activity that most people can relate to as well as accomplish, healthy people with favorable body weights and compositions are active equivalent to walking briskly an hour or more a day. Hence, the equivalent of walking briskly for 60 mm/day became the physical activity recommendation by the IOM Macronutrient panel. The physical activity recommendation was only a small part of the overall list of recommendations in dietary macronutrient composition (Chapter 2), but for the first time dietary and physical activity recommendations were combined and presented in quantifiable terms. Hence, on a population basis, the recommendation for “a minimum of 30 minutes of physical activity of moderate intensity (such as brisk walking) on most, if not all, days of the week” in the 1996 Surgeon General’s report has been more precisely determined and the recommendation is for activity equivalent to 60 mm/day of brisk walking.
In short, like the 1996 Surgeon General’s report on the health benefits of physical activity, the 2002 IOM Macronutrient Report combining physical activity and dietary recommendations represents a major departure from previous practices. It is testament to the growing recognition that prudent dietary and physical activity habits are important in promoting physical and mental health throughout the life cycle.
Source: McGraw Hill, Brooks, Fahey, Baldwin – Exercise Physiology, Human Bioenergetics and Its applications – Fourth Ed(book)
