The Cardiovascular System and Physical Activity
Edited By: Jasleen Sekhon
The cardiovascular system is a crucial system that allows your body to perform basic life-sustaining functions. It has 3 components: blood which contains oxygen, nutrients, and waste, blood vessels that carry the blood, and the heart which pumps the blood throughout the body. The main functions of the cardiovascular system are to make sure the body is supplied with oxygen and nutrients and to carry away things it doesn’t need.
Your heart is working all day and night even when you are asleep and circulates about 2,000 gallons of blood every day
Your heart is about the size of your fist, but the blood vessels run throughout your body so the network is as tall and wide as you.
The blood vessels in your body are so numerous to supply the entire body such that if they were all laid flat, they would cover a total distance of 100,000 kilometers, equivalent to two and a half times round the earth!
Cardiovascular diseases (CVDs) are the leading cause of death worldwide, accounting for 32% of all global deaths. Of which, 85% were due to heart attack and stroke.
CVDs include conditions that effect the blood vessels supplying:
The heart muscle itself - coronary artery disease (CAD)
The brain - cerebrovascular disease
The arms and legs - peripheral vascular disease
The venous system of the legs as a blood clot (Deep vein thrombosis)
The clot can dislodge and travel up to the heart then to the lungs (Pulmonary embolism)
A common cause of CVD is atherosclerosis, or cholesterol plaque buildup in the vessel wall which narrows the blood vessel and restricts the amount of blood flow that it can supply
Physical activity and the cardiovascular system
In clinical practice, the gold standard for patients diagnosed with stable CAD is a stenting procedure to widen the involved arteries called percutaneous coronary intervention.
Physical activity is a known modifiable risk factor that can prevent getting the disease, and patients can still benefit from exercise after a coronary intervention, however since these patients are more likely to experience a myocardial infarction (heart attack) due to exertion, it is essential to be cleared for exercise by your doctor
Regular exercise is known to have many health benefits, but can also significantly lower the risk of CVD
Improving fitness levels in both men and women can reverse the rates of all-cause mortality and CVD mortality
Studies show that physical activity when sustained is “associated with a more favorable inflammatory marker profile, decreases heart failure risk, and improves survival at 30 years follow-up in individuals with coronary artery disease” (Pinckard et al., 2019)
Kinds of exercise you can do:
It has long been shown that exercise reduces the risk of CAD with generally higher levels of activity receiving the most benefits. So, the higher the level of activity, the lower the risk of CAD right? Not entirely. Studies have found that the risk reduction in subjects that participated in the highest running intensity plateaued or even had a loss in protection.
However, the literature does agree that before high level of intensity is reached there is a benefit to increasing exercise intensity and most importantly, even participating in a low level of activity significantly protects against CAD compared to nonactive patients.
Which exercise program is best is still a topic of debate, however since doing something is still better than doing nothing, you can find a method of staying active that is tolerable and most importantly, sustainable for you.
A common recommendation is aerobic exercise such as walking, jogging, or cycling, aim for moderate to vigorous activity on most if not all days of the week and set a target for 2.5 hours a week of exercise
How Specific SES groups are affected
There are many contributors that make up a person’s health. Socioeconomic status (SES) has been studied in this context and research reveals SES is inversely associated with CVD risk in men and women meaning low SES has the highest CVD risk
While there are many reasons how SES can affect cardiac health, multiple behavioural and psychosocial risk factors exist among those of low SES that can explain this trend.
Parental SES, early-life factors, health service inequities all contribute to the CVD risk in people of low SES living in high-income countries
What is your cardiovascular system? (2021). Cleveland Clinic. https://my.clevelandclinic.org/health/body/21833-cardiovascular-system
What are blood vessels? (n.d.). AmealPeptide. https://www.amealpeptide.com/report/blood_vessels/
Pinckard, K., Baskin, K. K., & Stanford, K. I. (2019). Effects of Exercise to Improve Cardiovascular Health. Frontiers in cardiovascular medicine, 6, 69. https://doi.org/10.3389/fcvm.2019.00069
Winzer, E. B., Woitek, F., & Linke, A. (2018). Physical Activity in the Prevention and Treatment of Coronary Artery Disease. Journal of the American Heart Association, 7(4), e007725. https://doi.org/10.1161/JAHA.117.007725
Coronary Artery Disease: Exercising for a Healthy Heart. (n.d.). My Health Alberta. https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=te7797
Clark, A. M., DesMeules, M., Luo, W., Duncan, A. S., & Wielgosz, A. (2009). Socioeconomic status and cardiovascular disease: risks and implications for care. Nature reviews. Cardiology, 6(11), 712–722. https://doi.org/10.1038/nrcardio.2009.163