Cardiovascular Fitness
Cardiovascular Fitness

Cardiovascular Fitness

Lead Author(s): Denel Bingel

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Designed for Exercise Science students, and for those hoping to become certified personal trainers, this text provides science basics along with opportunities to integrate these principles and apply them to real world clients.

The Benefits of Cardiovascular Exercise

Objectives:

  • Define cardiovascular exercise.
  • Describe the benefits of performing cardiovascular exercise, including physiological, health, performance, and psychological benefits.

Cardiovascular (CV) endurance is arguably the most important component of physical fitness. People of all ages can improve the quality of their lives and reduce the risks of disease with ongoing participation in moderate physical activity and exercise. Daily exercise will also enhance one’s mental well-being and promote healthy musculoskeletal function throughout life.

What Cardiovascular Exercise?

Cardiorespiratory fitness refers to the ability of the circulatory and respiratory systems to supply oxygen to the muscles during physical activity. Aerobic exercise helps the body work more efficiently and is especially important in preventing many chronic conditions including diseases of the CV system, diabetes, and cancer. CV exercise also increases feelings of well-being and intellectual performance. A poorly conditioned heart has to pump more often just to keep a person alive. This translates to the person not being able to perform activities of daily living (ADL) such as yard work, caring for children, or running to catch the bus.

The typical American is NOT a good model. Although exercise is vital to healthy lifestyle, more than half of U.S. adults do not get ≥ 30 minutes of moderate-intensity exercise per day at least 5 days per week (Centers for Disease Control and Prevention [CDC] 2007a). The American College of Sports Medicine (ACSM) recommends aerobic exercise 3–5 times per week for 20–60 minutes per session, at an intensity that maintains the heart rate between 65% and 90% of the maximum heart rate (ACSM, 2006).


Image courtesy of "Mike" Michael L. Baird under CC BY 2.0

Although we will discuss the anatomy and physiology of the CV system in later chapters, a basic introduction is warranted. The main purpose of the CV system is to transport oxygen and nutrients to the organs and tissues of the body, as well as to remove CO2 and waste. As a person breathes, oxygen is taken up in the lungs and transported to the heart. The heart then pumps the oxygenated blood through the circulatory system to the organs and muscles. At the cellular level oxygen is then used to convert the food we eat into the energy necessary for basic metabolism or physical activity.

Exercise creates a need for greater energy, causing adaptations to the system. CV exercise is described as activity using large muscle groups continuously for a given period of time. Some examples of CV activities are jogging, swimming, biking, kickboxing, zumba, basketball, and soccer.

Everyone who participates can expect a number of benefits from training. Researchers are continually investigating how certain levels of physical activity may positively affect cardiovascular, musculoskeletal, respiratory, and endocrine function, as well as mental health. For the purpose of this chapter, the benefits of CV exercise have been divided into athletic benefits, health benefits, physiological benefits, and psychological benefits

Cardiovascular Exercise Can Improve Athletic Performance

When training the CV system, one must look at individual athletes and the sport they play. In exercise science, the specificity principle tells us that we should train for the specific results we want. What sport performance would we like to improve? A basketball player will train differently than a baseball player. Putting athletic skill aside, no matter what sport you play, CV training can likely improve your performance.

Training can improve endurance. For example, a soccer player must be able to play for 90 minutes. A player cannot be successful without the ability to perform well throughout the whole game. Obviously skill is related to performance, but a high VO2MAX is also required to play well. VO2MAX is generally viewed as the best indicator of aerobic fitness. Briefly, VO2MAX is a measure of the highest amount of oxygen an athlete can distribute and use in the body to produce energy. In many endurance sports, an athlete must be able to produce energy for a long period of time. Increased VO2MAX allows the athlete to perform at a higher workload at maximal effort. Running around the track or back and forth across the field will become easier. The athlete will also be able to keep a lower HR at a given workload. After training, a given workload (e.g., a 6- minute mile) will become easier and elicit a lower HR response. CV training increases the use of fat for fuel, which spares glycogen. This is important so that the athlete doesn’t run out of fuel halfway through the game. CV training also conditions the body to increase the lactate threshold. This means that the body will tolerate high-intensity effort and not fatigue as quickly.

Image courtesy of Skeeze under CC0 Public Domain​

Image courtesy of Skeeze under CC0 Public Domain

Trained athletes have a faster recovery time, meaning trained individuals recover more rapidly after exercising. A fit system is able to restore homeostasis after exercise has disrupted it. This is especially important when competing in various events in a short time period or recovering over halftime of a game. You may notice this even as you walk up the stairs with unconditioned friends… it takes them 5 minutes to catch their breath! The principle of recovery heart rate will be used when we perform the 3- minute step assessment in the next chapter.

CV training can lead to increased speed and agility. An example would be a traditional suicide drill or box drill. CV training can include plyometric training, which can improve skills for basketball, volleyball, among other sports.

CV training can lead to better control of body fat. This is more important in some sports than others. Dancers, gymnasts, and body builders all need a very low percentage of body fat to perform well.


CV fitness

The most valid measure of cardiorespiratory fitness is:

A

Maximum heart rate

B

Target heart rate

C

50 yard dash

D

VO2MAX


Improved Physiological Cardiovascular Function

The CV system, including the heart, lungs, and blood vessels, will work more efficiently as the athlete becomes more conditioned. This reduces the effort required to perform activities of daily living (ADL). VO2MAX is arguably the best measure of CV fitness. VO2MAX is a measure of how much oxygen the body can transport and use to create energy at maximum effort. It encompasses many physiological adaptations. With chronic long-term exercise, individuals can increase their VO2MAX an average of 15–20%, although increases of 50% have been reported (McArdle, Katch, & Katch, 1996. Exercise improves myocardial strength. Like any other muscle, the heart responds to training by increasing in size and strength. This allows the heart to pump more blood each beat, raising the stroke volume. This allows the heart to beat less often (lower resting heart rate) but still supply the body with the needed amount of oxygen. The system also functions better at the cellular level. Chronic exercise will increase the number of capillaries, increase size and number of mitochondria, and reduce platelet stickiness.

Chronic exercise will lower blood pressure. Regular physical activity makes your heart stronger, and a stronger heart can pump more blood with less effort. If your heart can work less to pump, the force on your arteries decreases, lowering your blood pressure. Becoming more active can lower your systolic blood pressure—the top number in a blood pressure reading—by an average of 4–9 millimeters of mercury (mmHg). That is comparable to some blood pressure medications. If your blood pressure is at a desirable level—less than 120/80 mmHg—exercise can help keep it from rising as you age. It takes about 1–3 months for regular exercise to have an impact on your blood pressure. The benefits last only as long as you continue to exercise.

Image courtesy of ChadoNihi under CC0 Public Domain​

It will also improve the cholesterol profile by increasing HDL (the “happy, healthy” cholesterol) and decreasing the LDL (“lousy” cholesterol).

Increased blood volume has also been documented as a consequence of endurance exercise training. The hypervolemia may provide advantages of greater body fluid for heat dissipation as well as larger filling pressure for greater stroke volume and lower heart rates during exercise (Convertino, 1991). Exercise training can also increase hemoglobin and red cell mass, which enhances oxygen-carrying capacity.

Exercise can have either a positive or negative effect on the immune system. Moderate endurance exercise boosts immune function, whereas overtraining depresses it. Physically fit people get fewer colds and upper respiratory tract infections than people who are not fit. In addition to getting regular moderate exercise, you can strengthen your immunity by eating a balanced diet, controlling stress, and getting sufficient sleep. Athletes often do not consider rest an important part of training. Rest is required for the body to repair and the mind to relax.

Reduced Risk of Chronic Diseases

Physically active people have a lowered risk of death from all causes. Regular exercise will improve immune function and lower the risk of CV disease, cancer, type II diabetes, osteoporosis, and obesity.

Cardiovascular Disease

The leading health-related cause of mortality for men and women in the United States is cardiovascular disease (ACSM, 2006). Research indicates that hypertension, lipid profile, and inflammation (C-reactive protein) are appropriate markers of heart disease risk. Hypertension is a major health problem. Elevated systolic and diastolic blood pressure levels are associated with a higher risk of developing coronary heart disease (CHD), congestive heart failure, and stroke (Bouchard & Despres, 1995). Moderate- intensity aerobic exercise (40–50% of VO2MAX), performed three to five times per week for 30–60 minutes per session appears to be effective in reducing blood pressure (when elevated). In many cases, clients can reduce elevated blood pressure by decreasing weight and lowering alcohol and salt intake in their diet. Regular exercise can improve lipid profile by raising HDL and lowering LDL. It has also been shown to reduce inflammation.

The medical community suggests the link between high levels of cholesterol and CHD has been established through long-term studies. Currently, many debate whether this is completely true. Some researchers suggest that chronic inflammation is to blame (Roifman et al, 2011). Exercise is effective at reducing inflammation (Gleeson et al, 2011).

It is well established that a sedentary lifestyle contributes significantly to the development of CHD and to unfavorable elevation of blood fats and cholesterol levels; physical activity plays an important role in decreasing these health risks.

Physical activity exerts a positive effect in lessening the risk of stroke in men and women.

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Individuals who engage in moderate to high amounts of physical activity have a lower risk of stroke incidence compared with people who accumulate little exercise. Statistics show that those who are moderately active have a 20% lower risk of stroke while those who are highly active have a 27% lower risk of stroke (Sacco et al., 2006). Sacco and colleagues also suggest that moderate to high levels of physical activity tend to lower blood pressure (if high), reduce body weight (if overweight), enhance vasodilation of blood vessels (widening of interior of blood vessels), and promote cardiovascular health.

Cancer

CV exercise has a positive effect on the immune system in general, so it is not hard to believe that it can lower the risk of cancer. Physical activity is correlated with a lower incidence of colon cancer in men and women, and breast cancer in women. Lee (2003) reports that physically active men and women have a 30–40% reduction in relative risk for colon cancer compared with their inactive counterparts. In addition, physically active women have a 20–40% reduction in relative risk for breast cancer compared with their inactive counterparts. Although more research is needed, it appears that physically active individuals may also have a lower risk of lung cancer, although lung cancer is relatively uncommon in nonsmokers (Lee, 2003).


Cancer

What types of cancer are most affected by CV exercise?


Type II Diabetes

Type II diabetes has reached endemic proportions, affecting 170 million individuals worldwide (Stumvoll, Goldstein, & van Haeften, 2005). Physical inactivity can lead to the weakening of the body’s insulin regulatory mechanisms. Elevated insulin and blood glucose levels may occur. When insulin function starts breaking down, the body’s blood sugar levels rise, leading eventually to the onset of type II diabetes. Previously a disease of older adults, diabetes incidence is growing among youth and younger adults, due to sedentary lifestyles. “Regular aerobic exercise meaningfully increases insulin sensitivity and glucose metabolism, which means the body’s cells can more efficiently transport glucose into the cells of the liver, muscle and adipose tissue” (Steyn et al., 2004).

Osteoporosis

Osteoporosis is a degenerative disease characterized by a loss of bone mineral density resulting in a susceptibility to bone fractures and health problems. Weight-bearing exercise helps build bone at young ages and maintain bone density with aging. Most CV exercise will stimulate bone growth. Physical activities that stimulate bone growth must be weight bearing, meaning the body holds up its own weight. Therefore, basketball or running would be better than biking or swimming. Both resistance training and weight- bearing aerobic exercise provide a stimulus for bone growth (Kohrt et al., 2004).

Body Composition

Obesity has risen to epidemic levels in the United States, with more than 65% of adults overweight and 31% obese (ACSM, 2006). Obesity is linked to various disease states, including hypertension, type II diabetes, CHD, and stroke. Cardio exercise increases calorie expenditure during exercise. If exercise is intense, the calorie burn can last for hours after exercise (Excess Post Exercise Oxygen Consumption or “EPOC”).According to the ACSM (2006), weight loss is best achieved when moderate-intensity cardiovascular exercise is increased up to 200–300 minutes accumulated over 5–7 days per week. CV exercise alone does not cause permanent changes to the body’s metabolism. Once the body has returned to homeostasis, its metabolism is back to prior levels. Therefore, the most effective way to lose weight long term includes resistance training in order to increase lean body mass. An effective program will also include some behavioral changes and possible calorie restriction.


Health Benefits

Which are health benefits of regular aerobic exercise?

A

Lower risk of CV disease

B

Lower risk of type II diabetes

C

Increased bone density

D

All of the above


Better Psychological Health

Although not usually the first thing that comes to mind when discussing exercise, CV can play a large role in improving psychological health (Dubbert, 2002). CV exercise has been shown to lessen anxiety and depression. In some cases, exercise has been shown to be more effective than antidepressant medication (Dunn et al., 2002). In addition, even acute bouts of exercise may improve a person’s present mood state. It has been shown that a single bout of 25–60 minutes of aerobic exercise (at low, moderate, or high intensity) increases positive mood feelings while also decreasing negative mood feelings (Lane & Lovejoy, 2001; Fox, 1999). It also appears that both acute exercise bouts and chronic exercise training programs have a positive effect on people with clinical depression (Dunn et al., 2002). The results of over 30 published papers substantiate a link between acute and chronic exercise and the reduction of anxiety (Scully et al., 1998).

Exercise can improve sleep. Studies show that regular exercise can help you fall asleep and help you improve sleep quality. Getting enough sleep (at least 7 hours) is important for mood, productivity, performance, and health. It is generally suggested not to exercise a few hours before bedtime.

Exercise can help to reduce stress. Fit individuals are capable of managing stress more effectively than those who are less fit (Hassmen, Koivula, & Uutela, 2000).

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Exercise also has a positive influence on self-esteem (Callaghan, 2004). The effect appears to be more potent in those with lower self-esteem. Perceived sport competence, physical condition, body image, and strength contribute to self-esteem (Scully et al., 1998). Exercise provides a medium for social interaction, whether through a pick-up game of basketball or a zumba class.

CV exercise can lead to enhanced intellectual function and improved work productivity. For example, a study from the University of Bristol shows that exercise during the workday improves job performance. After exercising, participants returned to work more tolerant of themselves and more forgiving of their colleagues. Their work performance was consistently higher. They improved their time management and mental sharpness. The superior productivity surprised the researchers, who simply hypothesized that it would improve mood (Coulson, McKenna, Field, 2008). So exercising before your next exam might be a good idea!

And CV exercise is just FUN! If people can find something they enjoy, they will stick with it and realize all of the benefits that exercise offers.

Image courtesy of PublicDomainPictures by CC0 

As future health and fitness professionals, it is important to educate the public about all the benefits of exercise. Cardiovascular exercise has been proven to increase CV function, increase VO2MAX, Lower resting heart rate, Improve cholesterol profile,  Lower risk of some cancers, Lower risk of heart disease and stroke, Lower risk of type II diabetes, Lower body weight, Lower blood pressure, lessen anxiety, improve sleep, increase intellectual function, improve immune system function, improve athletic endurance, improve recovery time, social interaction, enjoyment. Exercise is a HUGE part of a healthy lifestyle.



Why Do Cardio Exercise?

Summarize this chapter by listing benefits of CV exercise. Place an asterisk next to one benefit you were unaware of prior to class (one per section, total of four). Please complete all four sections and submit to your instructor.​


Q1.1

Disease Prevention Benefits:

  1. Example: Lower risk of CHD, helps to prevent plaque buildup in the coronary arteries

2.

3.

4.

5.


Q1.2

Physiological Benefits:

  1. Example: Lower RHR, which means the heart can work more efficiently

2.

3.

4.

5.


Q1.3

Psychological Benefits:

  1. Example: Exercise can reduce depression. In some studies, exercise worked just as well as medication.

2.

3.

4.

5.


Q1.4

Performance Benefits:

  1. Example: CV exercise can increase endurance on the field in sports such as soccer.

2.

3.

4.

5.


References:

American College of Sports Medicine. (2006) ACSM's Guidelines for Exercise Testing and Prescription 7th Edition. Philadelphia, PA: Lippincott Williams & Wilkins

Bouchard, C., & Despres, J.P. 1995. Physical activity and health: Atherosclerotic, metabolic, and hypertensive diseases. Research Quarterly for Exercise and Sport, 66, 268–75.

Brosse, A.L., et al. 2002. Exercise and the treatment of clinical depression in adults: Recent findings and future directions. Sports Medicine, 32 (12), 741–60.

Callaghan, P. 2004. Exercise: A neglected intervention in mental health care? Journal of Psychiatric and Mental Health Nursing, 11, 476–83.

Centers for Disease Control and Prevention. 2007a. U.S. physical activity statistics.http://apps.nccd.cdc.gov/PASurveillance/StateSumResultV.aasp;(BROKEN LINK) retrieved June 20, 2007.

Convertino, Victor A. "Blood volume: its adaptation to endurance training."Medicine and Science in Sports and Exercise 23.12 (1991): 1338-1348.

J.C. Coulson, J. McKenna, M. Field, (2008) "Exercising at work and self-reported work performance", International Journal of Workplace Health Management, Vol. 1 Iss: 3, pp.176 - 197

Dubbert, P.M. 2002. Physical activity and exercise: Recent advances and current challenges. Journal of Consulting Clinical Psychology, 70 (3), 526–36.

Dunn, A.L., et al. 2002. The DOSE study: A clinical trial to examine efficacy and dose response of exercise as treatment for depression. Controlled Clinical Trials, 23 (5), 584– 603.

Fox, The influence of physical activity on mental well-being. Public Health Nutr. 1999 Sep;2(3A):411-8.

Gleeson, Michael, et al. "The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease." Nature Reviews Immunology 11.9 (2011): 607-615.

Hassmen, P., Koivula, N., & Uutela, A. 2000. Physical exercise and psychological well- being: A population study in Finland. Preventative Medicine, 30 (1), 17–25.

Kravitz. The 25 Most Significant Health Benefits Of Physical Activity & Exercise, IDEA Fitness Journal » October 2007

Lane, A.M., & Lovejoy, D.J. 2001. The effects of exercise on mood changes: The moderating effect of depressed mood. Journal of Sports Medicine and Physical Fitness, 41 (4), 539–45.

Lee, I.M. 2003. Physical activity and cancer prevention—data from epidemiologic studies. Medicine & Science in Sports & Exercise, 35 (11), 1823–27.

McArdle, W.D., Katch, F.I., & Katch, V.L. 1996. Exercise physiology: Energy, nutrition, and human performance. Baltimore, Maryland: Williams & Wilkins.

Roifman, I., Beck, P. L., Anderson, T. J., Eisenberg, M. J., & Genest, J. (2011). Chronic inflammatory diseases and cardiovascular risk: a systematic review. Canadian Journal of Cardiology, 27(2), 174-18

Sacco, R.L., et al. 2006. Guidelines for prevention of stroke in patients with ischemic stroke or transient ischemic attack. Stroke, 37, 577–617.

Scully, D., et al. 1998. Physical exercise and psychological well-being: A critical review. British Journal of Sports Medicine, 32, 111–20.

Steyn, N.P., et al. 2004. Diet, nutrition and the prevention of type 2 diabetes. Public Health and Nutrition, 7 (1A), 147–65.

Stumvoll, M., Goldstein, B.J., & van Haeften, T.W. 2005. Type 2 diabetes: Principles of pathogenesis and therapy. Lancet, 365,1333–46.