What is the ability of the cardiovascular system of the body to supply energy during continous?

Your circulatory system, also called the cardiovascular system or vascular system, transports oxygen, nutrients and hormones to your body's cells to use for energy, growth and repair. Your circulatory system also removes carbon dioxide and other wastes your cells do not need.

These key parts of your circulatory system maintain blood flow to your body so you can survive:

blood, made up of cells and plasma
the heart, a muscular organ that pumps blood to all parts of your body
blood vessels, a network of arteries, capillaries and veins to carry blood pumped by your heart

Illustration showing the circulatory system.

Blood that is low in oxygen collects in your heart's right atrium, one of the heart’s 4 chambers.

It moves into the right ventricle, which pumps this blood to your lungs where your red blood cells pick up oxygen and get rid of carbon dioxide. You exhale the carbon dioxide.

The oxygen-rich blood returns to your heart's left atrium, then into your left ventricle. The left ventricle pumps oxygen-rich blood through your aorta, into your arteries, then to all parts of your body. Along the way, the blood gathers food nutrients from your small intestine.

As it enters the capillaries, your blood makes close contact with tissues and cells. It delivers oxygen and nutrients and removes carbon dioxide and wastes. Now low in oxygen, the blood travels through the veins to return to your heart's right atrium, where the circuit starts all over again.

Cardiovascular disease

Cardiovascular disease (CVD) refers to all diseases of the heart and blood vessels.

Most CVD occurs when fatty substances, called plaque or atheroma, build up in the lining of blood vessels, causing them to narrow and allow less blood to pass through. This process is called atherosclerosis.

Atherosclerosis causes coronary heart disease, also known as ischaemic heart disease. The slowing of the blood flow reduces the oxygen and nutrients available to the heart muscles. This can cause angina or a heart attack, which will require emergency medical attention. The most common symptom of heart attack or angina is chest pain.

When the supply of blood to part of the brain is interrupted because of a blocked or burst artery, a person will have a stroke. A stroke is also an emergency and will require urgent medical treatment.

Read more about heart problems and cardiovascular health here.

High or low blood pressure

As your heart pumps blood into your arteries, the blood pushes against the artery walls. This is what determines your blood pressure. Most doctors consider that a healthy blood pressure is higher than 90/60mm/Hg and lower than 140/90mm/Hg.

High blood pressure, also known as hypertension, can raise your risk of cardiovascular disease. It is the most common condition of the circulatory system.

Low blood pressure, also known as hypotension, is a sign of good health for some people but can be a problem for others. If you have symptoms of low blood pressure, such as dizziness or fainting, you should see a doctor.

2. What is the ability of the cardiovascular system of the body to supply energy duringcontinuous physical activities such as biking and running?A. AerobicsB. Aerobic ExerciseC. Aerobic FitnessD. Zumba

Cardiorespiratory fitness is defined as a component of physiologic fitness that relates to the ability of the circulatory and respiratory systems to supply oxygen during sustained physical activity.

From: The Sports Medicine Resource Manual, 2008

Cardiorespiratory fitness (CRF) refers to the ability of the circulatory and respiratory systems to supply oxygen to skeletal muscles during sustained physical activity. The primary measure of CRF is VO2 max.[1] In 2016, the American Heart Association published an official scientific statement advocating that CRF be categorized as a clinical vital sign and should be routinely assessed as part of clinical practice.[1]

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.[2] A 2005 Cochrane review demonstrated that physical activity interventions are effective for increasing cardiovascular fitness.[3]

There are many benefits of cardiorespiratory fitness. It can reduce the risk of heart disease, lung cancer, type 2 diabetes, stroke, and other diseases. Cardiorespiratory fitness helps improve lung and heart condition, and increases feelings of wellbeing.[2] Additionally, there is mounting evidence that CRF 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 CRF were associated with early deaths <65 years old among recent generations. Low CRF might be emerging to a new risk factor for early death among US Baby Boomers and Generation Xers.[4] Significantly, CRF can be added to these traditional risk factors to improve risk prediction validity.[1]

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 and 85% of the maximum heart rate.[5]

The cardiovascular system responds to changing demands on the body by adjusting cardiac output, blood flow, and blood pressure. Cardiac output is defined as the product of heart rate and stroke volume which represents the volume of blood being pumped by the heart each minute. Cardiac output increases during physical activity due to an increase in both the heart rate and stroke volume.[6] At the beginning of exercise, the cardiovascular adaptations are very rapid: "Within a second after muscular contraction, there is a withdrawal of vagal outflow to the heart, which is followed by an increase in sympathetic stimulation of the heart. This results in an increase in cardiac output to ensure that blood flow to the muscle is matched to the metabolic needs".[7] Both heart rate and stroke volume vary directly with the intensity of the exercise performed and many improvements can be made through continuous training.[citation needed]

Another important issue is the regulation of blood flow during exercise. Blood flow must increase in order to provide the working muscle with more oxygenated blood which can be accomplished through neural and chemical regulation. Blood vessels are under sympathetic tone; therefore, the release of noradrenaline and adrenaline will cause vasoconstriction of non-essential tissues such as the liver, intestines, and kidneys, and decrease neurotransmitter release to the active muscles promoting vasodilatation. Also, chemical factors such as a decrease in oxygen concentration and an increase in carbon dioxide or lactic acid concentration in the blood promote vasodilatation to increase blood flow.[8] As a result of increased vascular resistance, blood pressure rises throughout exercise and stimulates baroreceptors in the carotid arteries and aortic arch. "These pressure receptors are important since they regulate arterial blood pressure around an elevated systemic pressure during exercise".[7]

Although all of the described adaptations in the body to maintain homeostatic balance during exercise are very important, the most essential factor is the involvement of the respiratory system. The respiratory system allows for the proper exchange and transport of gases to and from the lungs while being able to control the ventilation rate through neural and chemical impulses. In addition, the body is able to efficiently use the three energy systems which include the phosphagen system, the glycolytic system, and the oxidative system.[6]

In most cases as the body is exposed to physical activity, the core temperature of the body tends to rise as heat gain becomes larger than the amount of heat lost. "The factors that contribute to heat gain during exercise include anything that stimulate metabolic rate, anything from the external environment that causes heat gain, and the ability of the body to dissipate heat under any given set of circumstances".[6] In response to an increase in core temperature, there are a variety of factors which adapt in order to help restore heat balance. The main physiological response to an increase in body temperature is mediated by the thermal regulatory center located in the hypothalamus of the brain which connects to thermal receptors and effectors. There are numerous thermal effectors including sweat glands, smooth muscles of blood vessels, some endocrine glands, and skeletal muscle. With an increase in the core temperature, the thermal regulatory center will stimulate the arterioles supplying blood to the skin to dilate along with the release of sweat on the skin surface to reduce temperature through evaporation.[6] In addition to the involuntary regulation of temperature, the hypothalamus is able to communicate with the cerebral cortex to initiate voluntary control such as removing clothing or drinking cold water. With all regulations taken into account, the body is able to maintain core temperature within about two or three degrees Celsius during exercise.[7]

Aerobic conditioning
Central governor
Physical fitness
Exercise physiology
VO2 max

^ a b c Ross, Robert; Blair, Steven N.; Arena, Ross; Church, Timothy S.; Després, Jean-Pierre; Franklin, Barry A.; Haskell, William L.; Kaminsky, Leonard A.; Levine, Benjamin D. (2016-12-13). "Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association". Circulation. 134 (24): e653–e699. doi:10.1161/CIR.0000000000000461. ISSN 0009-7322. PMID 27881567. S2CID 3372949.
^ a b Donatello, Rebeka J. (2005). Health, The Basics. San Francisco: Pearson Education, Inc.
^ Hillsdon, M.; Foster, C.; Thorogood, M. (2005-01-25). "Interventions for promoting physical activity". The Cochrane Database of Systematic Reviews (1): CD003180. doi:10.1002/14651858.CD003180.pub2. ISSN 1469-493X. PMC 4164373. PMID 15674903.
^ Cao, Chao; Yang, Lin; Cade, W. Todd; Racette, Susan B.; Park, Yikyung; Cao, Yin; Friedenreich, Christine M.; Hamer, Mark; Stamatakis, Emmanuel; Smith, Lee (2020-01-30). "Cardiorespiratory Fitness Is Associated with Early Death Among Healthy Young and Middle-aged Baby Boomers and Generation Xers". The American Journal of Medicine. 133 (8): 961–968.e3. doi:10.1016/j.amjmed.2019.12.041. ISSN 0002-9343. PMID 32006474.
^ Pollock, M.L.; Gaesser, G.A. (1998). "Acsm position stand: the recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults". Medicine & Science in Sports & Exercise. 30 (6): 975–991. doi:10.1097/00005768-199806000-00032. PMID 9624661.
^ a b c d Brown, S.P.; Eason, J.M.; Miller, W.C. (2006). Exercise Physiology: Basis of Human Movement in Health and Disease. Lippincott Williams & Wilkins. pp. 75–247. ISBN 978-0781777308.
^ a b c Howley ET, Powers SK (1990). Exercise Physiology: Theory and Application to Fitness and Performance. Dubuque, IA: Wm. C. Brown Publishers. pp. 131–267. ISBN 978-0078022531.
^ Shaver, L.G. (1981). Essentials of Exercise Physiology. minneapolis, MN: Burgess Publishing Company. pp. 1–132. ISBN 978-0024096210.