34 SPENCER RM et al. Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp CVD and stroke by 20%." 4 The committee was tasked with defining cardiovascular health, a concept that encompasses the presence of 7 ideal health behaviors and factors, including physical activity level. Thus, the AHA claims that cardiorespiratory fitness is an uncertain risk factor, but physical activity at goal levels is an ideal health behavior. This review aims to

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... h physical activity from physical fitness, more specifically cardiorespiratory fitness, as well as to address the question whether physical inactivity and cardiorespiratory fitness are independent risk factors for CVD. Definition of Terms Although physical activity, exercise, and physical fitness are closely related, they are distinct and require unique assessment methods. Physical activity is defined as "any bodily movement produced by skeletal muscles that results in energy expenditure." 5 Physical activity is measured via criterion methods, objective methods, and subjective methods. 6 Criterion methods include doubly labeled water, indirect calorimetry, and the gold standard, direct calorimetry. Doubly labeled water measures metabolic rate and requires ingesting 2 isotopes of water and assessing the difference in elimination rates of the isotopes over a certain time period. 6 Indirect calorimetry uses oxygen consumption or carbon dioxide elimination to indirectly estimate energy expenditure, while direct calorimetry measures energy expenditure through heat production. 6 Objective methods of physical activity include pedometers, accelerometers, espite major improvements in its treatment, cardiovascular disease (CVD) remains the leading cause of death worldwide. 1,2 In 2012, 17.5 million people died of CVD and this figure is expected to grow to 23.6 million by 2030. 2 Thus, understanding risk factors is integral to the prevention of CVD-related morbidity and mortality. Preserving cardiovascular health and treating modifiable risk factors instead of advanced disease benefits the long-term health of patients. Models for risk prediction have evolved since cardiovascular epidemiology began in the 1930 s. Various 5-and 10-year risk prediction models have been widely adopted, and include common variables such as age, sex, cholesterol, smoking status, diabetes, and systolic and diastolic blood pressures (SBP, DBP). However, despite abundant research focused on understanding the effect of physical activity and fitness on cardiovascular outcomes, these risk models do not include physical activity or fitness. In Primary and primordial prevention of cardiovascular disease (CVD) requires not only identification of risk factors, but also appropriate and timely therapy. In order to prevent the expected increase in prevalence of CVD, it is essential that clinicians are aware of behavioral cardiovascular risk factors. A basic review is critical to clarify the difference between physical activity and fitness, as well as to discuss the role each plays in cardiovascular outcomes. We discuss observational epidemiological studies and randomized control trials that have examined the effect of physical activity and cardiorespiratory fitness on CVD. (Circ J 2016; 80: 34 -43)