Active Voice: Physical Activity – A Vital Health Measure

By Leonard A. Kaminsky, Ph.D., FACSM

Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM.

Lenny Kaminsky is a professor of exercise science at the Ball State University Human Performance Laboratory. He is the coordinator of the master’s degree program in Clinical Exercise Physiology and Director of the Adult Physical Fitness Program. His research interests center on the unique roles of physical activity, exercise, and physical fitness in the prevention and rehabilitation of chronic disease. He presently chairs an American Heart Association (AHA) Advisory Board, charged with establishing a national cardiorespiratory fitness registry.

This commentary provides an overview of the importance of physical activity assessment, as outlined in an AHA Scientific Statement, which published in late 2013 and developed by a writing group that Dr. Kaminsky co-chaired with Dr. Scott Strath.

Although great strides have been made in treatment of cardiovascular diseases (CVD), these diseases are still responsible for one in every three deaths in the United States. Prevention of CVD, therefore, is being re-emphasized as major goal by many organizations, including the American Heart Association (AHA) and the Centers for Disease Control and Prevention (2020 Impact Goals). A key component of this preventative strategy is to assess CVD risk factors. Although clinicians and allied health professionals do an excellent job of assessing five of the six modifiable CVD risk factors (smoking status, blood pressure, cholesterol, diabetes, and obesity), assessment of physical activity status is seldom performed.

One of the primary reasons for lack of physical activity assessment in the healthcare setting is the wide range of different methods that exist, with no clear understanding which would be the best choice. However, a 2013 Scientific Statement by the AHA now provides clinicians and researchers with an excellent resource to understand physical activity assessment and guide their selection of an appropriate method. Although the purpose of this AHA report was not to provide a comprehensive review of physical activity assessment, it does an excellent job of overviewing related key concepts. These concepts include explaining the four dimensions of physical activity (frequency, intensity, time, and type) and the four physical activity domains (occupational, domestic, transportation, and leisure time). Additionally, it describes the approaches to quantifying physical activity, including the elements of total energy expenditure (kilocalories), metabolic equivalents (METs), or time spent in different intensity levels. The difference between absolute (external work requirement) and relative (compared to the individual’s maximal capacity) intensity also is discussed and explained related to assessment of physical activity.

The most useful feature of this AHA Scientific Statement is the section that overviews how to select the best physical activity assessment method, which includes a decision-matrix – a series of questions with different answers leading to different recommendations. This guide provides clear suggestions of which physical activity assessment method would be appropriate, depending on considerations such as how many people need to be measured, how quickly are the results needed, and the financial resources available. The recommendations range from subjective, self-report approaches, to objective (simple to complex) monitoring. The user is guided through the selection process with an understanding of the advantages and disadvantageous of the different assessment choices.

Hopefully, this AHA Statement will lead more clinicians to assess physical activity, which can be considered a vital health measure. As such, physical activity assessment should be routinely performed along with the quantification of other major CVD risk factors.

Editor’s Note: ACSM issues Position Stands that evaluate and integrate advances in science related to sports, physical activity, health, and safety. In other publications, the College translates such information into educational resources for health professionals, for health policy decision makers, and for the general public. For the Position Stand that most closely relates to this Active Voice commentary, see Garber et al. Medicine in Science in Sports & Exercise® (2011).