<unk>  <unk>  refers to the ability of the circulatory and respiratory systems to supply oxygen to skeletal muscles during sustained physical activity. The primary measure of<unk>  is VO2 max. In 2016, the American Heart Association published an official scientific statement advocating that<unk>  be categorized as a clinical vital sign and should be routinely assessed as part of clinical practice. Regular exercise makes these systems more efficient by enlarging the heart muscle, enabling more blood to be pumped with each stroke, and increasing the number of small arteries in trained skeletal muscles, which supply more blood to working muscles. Exercise improves not just the respiratory system but the heart by increasing the amount of oxygen that is inhaled and distributed to body tissue. A 2005 Cochrane review demonstrated that physical activity interventions are effective for increasing cardiovascular<unk> . There are many benefits of<unk> . It can reduce the risk of heart disease, lung cancer, type 2 diabetes, stroke, and other diseases.<unk>  helps improve lung and heart condition, and increases feelings of wellbeing. Additionally, there is mounting evidence that<unk>  is potentially a stronger predictor of mortality than other established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes. Recently, a new study demonstrated the levels of<unk>  were associated with early deaths <65 years old among recent generations. Low<unk>  might be emerging to a new risk factor for early death among US Baby Boomers and Generation Xers. Significantly,<unk>  can be added to these traditional risk factors to improve risk prediction validity. The American College of Sports Medicine recommends aerobic exercise 3–5 times per week for 30–60 minutes per session, at a moderate intensity, that maintains the heart rate between 65–85% of the maximum heart rate.
Cardiorespiratory fitness
Cardiovascular fitness
Physical fitness
Exercise physiology
Physical strength
Cardiac reserve
Body composition
Breathing circuit