Departments of Exercise Science, University of South Carolina, Columbia, South Carolina, USA; Epidemiology/Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA.
Non-communicable chronic diseases (NCDs), such as cardiovascular disease, diabetes, and cancer, are currently responsible for 65% of all deaths worldwide and are projected to cause over 75% of all deaths by 2030. A substantial accumulation of epidemiological and experimental evidence has established a causal relationship between NCDs and well-known yet preventable risk factors (e.g., physical inactivity and obesity). Given that physical activity has both direct and indirect effects on the mortality and morbidity of NCDs via other risk factors (e.g., obesity, diabetes, and hypertension), it is now undeniable that sedentary lifestyles are one of the most significant public health problems of the 21st century. In 2007, the American College of Sports Medicine (ACSM) and American Medical Association (AMA) launched the Exercise is Medicine® (EIM) initiative in recognition of the fundamental importance of physical activity to health and well-being. EIM is on the forefront of a global movement to reduce sedentary lifestyles, foster implementation of exercise counseling into clinical practice, and disseminate exercise therapy on a global scale. If the devastating human losses and financial burden of inactivity-induced chronic disease are to be ameliorated, the wide-ranging cost-effective health benefits and financial feasibility of physical activity interventions must be appreciated and promoted.