'On the Web' is an internet-based supplement that provides additional web content to supplement the material in Concepts of Fitness and Wellness. Browse through the whole document to explore web content related to this concept. If you know the specific 'On the Web' number or page number of the web icon in the text you can click on the direct link you are looking for below. Click here to access the other Online Learning Center resources available from the McGraw Hill Website (http://www.mhhe.com/corbin7e).

The material available here is for the exclusive use of students and instructors using the Concepts-based textbooks. All rights reserved (McGraw Hill Higher Education).

On the Web - Concept 04

Web04-01: Health Benefits of Physical Activity

Web04-02: Sedentary Death Syndrome

Web04-03 Atherosclerosis and Cardiovascular Disease

Web04-04 Emerging Risk Factors for Heart Disease

Web04-05: Physical Activity and Heart Attack

Web04-06: Measurement and Interpretation of Blood Pressure

Web04-07: Advances in Medical Technology and Emergency Care

Web04-08: Physical Activity and Cancer

Web04-09: Physical Activity and Diabetes

Web04-10: Physical Activity and Osteoporosis

Web04-11: Functional Disability and Aging

Web04-12: Worksite Health Promotion

Web04-13: Heart Disease Risk Assessments

Web03-14: Supplemental Readings

Web04-15: Supplemental Readings

Web04-01: Health Benefits of Physical Activity

Coronary heart disease, cancer and strokes are considered to be the leading causes of death in the United States. To a large extent, these conditions are all directly related to lifestyle behaviors. Therefore, the REAL causes of death can actually be attributed to unhealthy lifestyles. A leading public health official estimated of the percentages of deaths that are related to different behaviors and environmental conditions. The second leading cause of preventable mortality was found to be diet/physical inactivity. While tobacco was found to have a stronger overall effect on health, the number of people at risk for smoking (~30%) is much lower than the number of people who are inactive (~50%) or those that are overweight/obese (~ 50%). Based on these figures, many scientists have concluded that physical inactivity and weight control have a greater "population attributable risk" than other established risks or conditions. In other words, more deaths could be prevented by getting the population to be physically active than could be spared by getting everyone to quit smoking. See figure below:

The health benefits of physical activity have now been well documented. The Surgeon General's Report on Physical Activity and Health provides the most definitive summary of the health benefits of an active lifestyle Click here to access key facts from the Surgeon General's Report on Physical Activity and Health

Web04-02: Sedentary Death Syndrome

":Sedentary Death Syndrome, or "SeDS," is the term developed by more than 200 of the nation's leading physiologists to diagnose the growing epidemic of physical inactivity and its relationship to chronic, preventable diseases. It is estimated that 60 percent of all Americans are currently at risk for SeDS, a condition that leads to premature disability or death. Approximately 2.5 million Americans will die prematurely in the next ten years due to SeDS, a number greater than all alcohol, guns, motor vehicles, illicit drug use and sexual behavior related deaths combined. These researchers call SeDS the second largest threat to public health!"

The data is now conclusive that inactivity is a major risk factor for many chronic diseases. As described in Web04-01, inactivity is second only to smoking as the largest threat to public health (it may become the largest risk because smoking rates have come down in recent years while inactivity has remained constant).

The term "Sedentary Death Syndrome" has caught on within the scientific community and the public at large. An advocacy group called Researchers Against Inactivity (RID) has been established to facilitate the dissemination of the message. Click here to see a list of related links on SeDS. To get a sense of how the message has spread type the phrase "Sedentary Death Syndrome" into a search on www.yahoo.com or www.google.com and follow some of the many links. The term has now been linked to the Word Spy website that tracks newly coined terms and phrases.

Web04-03 Atherosclerosis and Cardiovascular Disease

Atherosclerosis refers to the progressive blockages in arteries that are created when fatty substances build up inside the artery walls over time and cause a narrowing of the artery. The buildup inhibits blood flow to the affected region. In the heart, atherosclerosis can lead to blockage or occlusion of a vessel in the heart and lead to a heart attack (myocardial infarction). In the brain, the occlusions can precipitate a stroke or hemorrhage. Blockage in other vessels in the body leads to another type of cardiovascular disease known as peripheral vascular disease. This peripheral blockage is most likely to occur in the arteries of the lower abdomen leading to the legs, the renal arteries which supply blood to the kidneys, the carotid arteries which lead to the neck and brain, and the arteries that feed blood to the arms.

The atherosclerotic process typically begins with some damage to the walls of the arteries. High blood pressure, high levels of LDL cholesterol and compounds in cigarettes all cause some damage to the vessels. The immune system responds to heal the area but makes the area "sticky" by releasing various cytokines into the area. If a person has high levels of LDL cholesterol, the compounds in the cholesterol become stuck on the surface of the vessels and lead to the formation of fatty plaques (atherosclerosis). The American Heart Association (www.americanheart.org) has a number of excellent resource documents to help people understand the effect of cholesterol on decreasing their risks of heart disease. ).

Physical activity is known to reduce the buildup of atherosclerosis by decreasing cholesterol and blood pressure. Research has also demonstrated that exercise may decrease the activity of blood mononuclear cells and thereby reduce the amount of atherogenic substances that are released in the vessels. This beneficial effect on the immune system is another possible mechanism for the preventive benefits of physical activity on coronary heart disease.

Click here to read the American Heart Association's recommendation on physical activity.

Click here for more information on atherosclerosis from the American Heart Association's Heart and Stroke Encyclopedia.

Click here to learn about how diet may modify cholesterol levels and reduce atherosclerotic plaque.

Web04-04 Emerging Risk Factors for Heart Disease

The processes leading to the buildup of atherosclerotic plaque are quite complex. Scientists are still working to resolve how the process starts and to identify factors that may contribute to the process or that may speed it along. The lipid deposit theory described in the book is well established now and clearly plays a role but a number of other compounds appear to influence the atherosclerosis process. Some of these compounds may serve as important markers of atherosclerotic plaque or as additional risk factors that doctors can use to help screen patients that may be at risk. Compounds that have received a lot of attention in recent years are homocysteine, Apolipoprotein B (ApoB) and CRP.

• Homocysteine is an amino acid produced by the body during the metabolism of other amino acids. It is toxic to the endothelial cells that line the arteries and promotes the oxidation of LDL cholesterol. Both factors cause plaque to form in the arteries leading to atherosclerosis. Homocysteine levels have been considered as an important marker of risk for atherosclerosis but not a separate independent risk factor. Diet appears to be important in controlling or reducing homocysteine. Folic acid, an important nutrient in foods can convert homocysteine into a harmless amino acid (methionine). Folic acid can be found in a variety of foods but it is especially high in green vegetables (spinach, asparagus, broccoli) and legumes (beans, black eyed peas and nuts ). Individuals eating these foods probably meet the current USRDA of 400 ug/day. The AHA does not recommend supplemental amounts of folic acid in the diet unless individuals don't get enough in their diet. The FDA currently mandates that folic acid be included in all enriched grain/cereal products and it is estimated that this provides an additional 100ug/day for most Americans. The primary reason for this supplementation is to reduce the risk of neural tube birth defects but this supplementation should also contribute to lowering homocysteine levels in the population. Click here for more information on homocysteine from the American Heart Association's Heart and Stroke Encyclopedia. Click here to read or review the AHA Scientific Statement on Homocysteine, Diet and CVD.
• Apolipoprotein B particles are tiny fat particles that float around in the blood and contribute to the progression of atherosclerosis. Recent studies have shown that high levels of ApoB are a better predictor of heart disease risk than high levels of "bad" cholesterol (LDL). Similar to the frequently used ratio of LDL:HDL scientists now suggest that the ratio of ApoB to ApoA1 may provide a more effective diagnostic screen of a patients risk for atherosclerosis. Click here to read a recent press release on ApoB from WebMD. Click here to see an interactive model that shows conversions between the various compounds that are involved in the processing of lipids in the body. The description is intended only to demonstrate the complexity of these processes.
• C-Reactive Protein is a special type of protein produced by the liver that is only present during episodes of acute inflammation. Research has suggested that CRP may levels may be elevated in heart attacks but the specific role of CRP in coronary artery disease remains unclear. It is not clear if CRP is merely a marker of disease or whether it actually plays a role in causing atherosclerotic disease. Some experts consider elevated CRP to be a risk factor for coronary artery disease and clinical tests are often conducted to screen for this protein. Click here to read a brief overview of the role of CRP in heart disease by the American Heart Association.

Web04-05: Physical Activity and Heart Attack

The American Heart Association estimates that approximately a third of the population has high blood pressure without knowing it. The cause of high blood pressure is not known in 90-95% of the cases but it can be easily detected and controlled with proper medical attention. Many medications, known as antihypertensives are available to help people control their blood pressure. Some are called diuretics and help to lower blood pressure by promoting the excretion of excess water and sodium. Other drugs are referred to as "beta-blockers" which reduce the heart rate and the output of blood from the heart. Other classes of medications (ACE inhibitors or calcium antagonists) reduce blood pressure by interfering with the bodies' production of angiotensin, a compound that causes the arteries to constrict.

The decision of the right medication or treatment for control of high blood pressure must be done through appropriate medical attention. The important thing is to have your blood pressure checked so that corrective actions can be taken. Compared to people with controlled high blood pressure, people with uncontrolled high blood pressure are 3 times more likely to develop coronary heart disease, 6 times more likely to develop congestive heart failure and 7 times more likely to have a stroke. Because of the strong links to heart disease and stroke, increasing awareness about hypertension is a major goal of the American Heart Association (AHA). Click here for more information on hypertension from the American Heart Association's Heart and Stroke Encyclopedia.

The Effects of Physical Activity on Hypertension
Physical activity is not a complete cure-all for treating hypertension but it can be an important preventive measure and treatment option. It has been estimated that inactive and unfit individuals are at 30-50% greater risk of developing high blood pressure than more active and fit individuals. Physical activity is also beneficial for reducing high blood pressure. See the Physical Activity and Cardiovascular Health fact sheet prepared by the AHA. Also, check the current physical activity recommendations endorsed by the AHA.

Web04-06: Measurement and Interpretation of Blood Pressure

It is important that blood pressure is measured accurately. There are many ways to measure blood pressure including: at the doctor's office, at home, and at a place of business. Blood pressure can be measured manually or with an automated blood pressure cuff. Generally at home or a place of business an automated cuff is used, while a health expert may measure blood pressure manually. A manual reading takes proper training while automated cuffs require proper calibration for an accurate measurement.

A number of new technologies are available to assist with home monitoring of blood pressure. Click here to go to see examples of some of the new home monitoring technology available for monitoring blood pressure. It is also important to understand what these numbers mean. The American Heart Association explains how to interpret blood pressure results (AHA blood pressure results).

See AMA guide and reference the book.
http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZVV6DWGLC&sub_cat=74

This CDC website (www.cdc.gov/bloodpressure) also provides valuable information about blood pressure. It includes facts and statistics about blood pressure as well as valuable resources and prevention tips.

Web04-07: Advances in Medical Technology and Emergency Care

Regular activity and healthy lifestyles are the key to reducing early deaths from chronic diseases, but there is hope for those who have already developed heart disease. Open-heart bypass surgery has become much less common than less invasive angioplasty that involves inserting a catheter through a blood vessel in a limb into the heart. A balloon or laser is then used to break up deposits in the obstructed artery.

Many recent technological advances have contributed to the recent 3% drop in heart disease deaths. Examples include:

• Angioplasty for the brain. This procedure, formerly used only in the heart, uses a catheter with a balloon to clear an artery in the brain and a wire mesh cylinder (stent) to keep the artery open.
• Dual chamber pace makers. A device with two electrodes is placed in the heart muscle to synchronize the two halves of failing heart. The device reduces death rates.
• Statins and plaque busters. Statins are a new class of drugs that improve lipid profiles. Plaque busters, (referred to as "liquid Drano" for the heart) have even greater potential for clearing clogged arteries

See the following resources:
Angioplasty.org
Mayo Clinic
American Heart Association
Pacemakers
Statins

Web04-08: Physical Activity and Cancer

Cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells. Cancer is the second leading cause of death in America. Nearly 1 in 3 Americans will develop cancer and approximately 1 in 4 will die from cancer (American Cancer Society, 1996). Recent trends show that the prevalence of most cancers is declining (see Web24). Part of this reduction is due to better awareness and better treatment options. Additional progress can be made in cancer reductions through efforts to promote physical activity and healthy eating. The American Cancer Society has recently released a new document called "Nutrition and Physical Activity Guidelines for Cancer Reduction" that provides recommendations on appropriate diet and physical activity levels for reducing cancer risks. Click here to read the press release.

While physical activity has been shown to be beneficial for overall health and can reduce the risks of certain types of cancer, there is some evidence that extremely high levels of physical activity in adolescent males and young men can increase risks for testicular cancer. Lance Armstrong (an elite cyclist) recovered from testicular cancer and went on to win multiple Tour de France races. Click here to read information on physical activity and testicular cancer from the ACS web page.

Web04-09: Physical Activity and Diabetes

Diabetes is a metabolic disease characterized by chronic high blood sugar and insufficient insulin secretion or utilization (See Web 24-02). Diabetes is the 7th leading cause of death in America and prevalence rates have increased dramatically in recent years. The American Diabetes Association (www.diabetes.org) estimates that there are 15.7 million people or 5.9% of the population in the United States who currently have diabetes. While an estimated 10.3 million have been diagnosed, unfortunately, 5.4 million people are not aware that they have the disease.

The major types of diabetes are described below:

• Type I Diabetes (also called insulin dependent diabetes mellitus) is an auto-immune disease in which the body does not produce any insulin. It is generally considered to be a genetic disorder that is most often diagnosed in children and young adults. People with type I diabetes must take daily insulin injections to provide insulin since the pancreas is unable to produce or secrete it. Type 1 diabetes accounts for 5-10 percent of diabetes.
• Type II Diabetes (also called non-insulin dependent diabetes mellitus or NIDDM) is a metabolic disorder resulting from the body's inability to make enough, or properly use, insulin. Type 2 diabetes accounts for 90-95 percent of diabetes and rates are increasing due to the increasing prevalence of obesity and high levels of inactivity in the country.

Physical activity can significantly reduce a person's risk of diabetes and also help current diabetics by reducing insulin requirements. The Surgeon General's Report provides a detailed review of studies on physical activity and NIDDM. The Report indicates that "the epidemiology literature strongly supports a protective effect of physical activity on the likelihood of developing NIDDM in the populations studied." (p. 128). Additional information on physical activity and diabetes can be found at the American Diabetes Association or the Canadian Diabetes Association.

Visit the Heart of Diabetes webpage from the American Heart Association to learn how diabetes increases the risk of cardiovascular disease (http://www.s2mw.com/heartofdiabetes/index.html.)

Web04-10: Physical Activity and Osteoporosis

Osteoporosis is a generalized thinning and demineralization of the bone that typically occurs in postmenopausal women and is associated with aging and physical inactivity. Osteoporosis develops when the calcium present in the bones slowly decreases and the bones become brittle and prone to fracture.

Bone density is measured by bone scan machines that examine the density of specific bones in the body. The image below shows the bone density graph for the lumbar spine of a 36 year old male. The blue zone is the normal range. Note that with age, there is a normal, progressive decline in bone density that occurs. If bone density gets to a certain critically-low level (signifying osteoporosis) then there is an increased risk for bone fractures, particularly of the spine, hip, and wrist. Osteoporosis is thought to cause more than 1.5 million fractures each year. While not life threatening by itself, approximately 20 percent of hip fracture victims die within one year, usually from complications such as pneumonia. Hip fracture also limits mobility and impairs the quality of life for many elderly individuals.

The National Osteoporosis Foundation (www.nof.org) strongly endorses the importance of physical activity to maintain bone health. They have released a custom exercise video called Be BoneWise (http://www.nofstore.org/Merchant2/merchant.mvc?Screen=PROD&Product_Code=V140&Category_Code=CR&Product_Count=0) to promote appropriate weight bearing exercise to reduce risks of osteoporosis.

Web04-11: Functional Disability and Aging

By the year 2025, approximately 25% of the population in the U.S. will 60 or older (see map below). Because of the expanding geriatric population, there is concern about the additional health care costs associated with disability in old age. Physical activity and healthy lifestyles can reduce the likelihood of disability and improve the quality and quantity of life for all Americans. A number of research studies have documented that physical activity and other healthy lifestyles can help to slow the normal aging process. By shortening or "compressing" periods of morbidity prior to death a person can maintain a higher quality of life for their later years. This is also known as a "compression of morbidity".

The American College of Sports Medicine has posted a Position Stand called "Exercise and Physical Activity for Older Adults" that summarizes the benefits of activity for this population. Visit the ACSM (www.acsm.org) webpage to download the report (access through the Position Stands section).

Web04-12: Worksite Health Promotion

The Wellness Councils of America (WELCOA) is a national organization dedicated to improving the lifestyles of Americans particularly through worksite health promotion. WELCOA provides resources for companies to use to create or enhance their own worksite health promotion program (such as newsletters, power point presentations, and intervention programs). Local wellness councils have also been organized under the national umbrella to help support businesses locally. Through a series of steps, companies can apply for a "Well Workplace" designation that provides recognition for companies that have taken action to improve the health of their employees. More information can be found at WELCOA.

Successful worksite health promotion programs have been shown to increase productivity, decrease absenteeism and medical care costs, and increase the company's profit. Companies with well established comprehensive programs have been shown to save $4 for every dollar the company invested into the program. Several companies such as Wellsource and Trale provide lifestyle management tools for companies to purchase to help create and maintain their worksite health promotion programs. These companies provide a variety of easy to manage resources that allow companies to customize the program to meet their specific needs.

More worksite health promotion resources can be found at the following links:
ACSM's Worksite Health Promotion Manual: http://www.exrx.net
ACSM-Worksite Health Promotion Special Interest Group: http://www.uwsp.edu

Web04-13: Heart Disease Risk Assessments

There are a number of lifestyle behaviors that can influence a person's risk of cardiovascular disease. The Heart Disease Risk Factor Assessment in Lab 6A provides a way to systematically look at your overall risk. A number of other online assessments are available. It is important to judge the quality of the web sites and the quality of the assessment before considering them for your own use. Two quality online assessments are described below.

The American Heart Association has developed an interactive heart disease risk assessment that is directly linked to results from the famous Framingham Heart Study. It may be interesting to compare the results from the different assessments. Click here to access the AHA assessment.

The Harvard Center for Cancer Prevention has developed several interactive assessments for different diseases including heart disease. The Center has utilized scientific research to create its assessments. The interactive tool will estimate your risk for developing heart disease as well as provide prevention information based on your risks. Click here to access the Harvard Center assessment.

Web04-14: Web Resources

Alzheimer's Association - www.alz.org

American Cancer Society - www.cancer.org

American Diabetes Association - www.diabetes.org

American Heart Association - www.americanheart.org

American Lung Association - www.lungusa.org

Arthritis Foundation - www.arthritis.org

Canadian Diabetes Association - www.diabetes.ca

Centers for Disease Control and Prevention - www.cdc.gov

Healthy People 2010 - www.health.gov/healthypeople

National Osteoporosis Foundation - www.nof.org

National Stroke Association - www.stroke.org

Worksite Wellness Information - healthproject.stanford.edu/koop/work.html

Web04-15: Supplemental Readings

References new to 7e/14e

American Heart Association. 2005. Metabolic Syndrome. Dallas, TX: American Heart Association. Available at www.americanheart.org/presenter.jhtml?identifier=4756

Chenoweth, D. et al. 2006. The cost of sloth: Using a tool to measure the cost of physical activity. ACSM's Health and Fitness Journal. 10(2):8-13.

Jurea, R. et al. 2005. Physical activity and nontraditional CHD risk factors. President's Council on Physical Fitness and Sports Research Digest. 6(4): 1-8.

Ogden, C. L. et al. 2006. Prevalence of overweight and obesity in the United States. Journal of the American Medical Association. 295(13), 1539-1548.

U. S. Department of Health and Human Services. 2004. Bone Health and Osteoporosis: A Report of the Surgeon General. Rockville, MD: U.S.D,H.H.S., Office of Surgeon General.

Rererences from Past Editions

• ACSM's Health and Fitness Journal. 2(2)(1998): entire issue. This issue contains 11 articles dealing with the health benefits of physical activity.
• American College of Sports Medicine. The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults. Medicine and Science in Sports and Exercise. Medicine and Science in Sports and Exercise, 30(6)(1998):975.
• American College of Sports Medicine. Exercise and Physical Activity for Older Adults. Medicine and Science in Sports and Exercise. Medicine and Science in Sports and Exercise, 30(6),(1998):992.
• American Heart Association. "A Statement on Exercise: Benefits and Recommendations for Physical Activity Programs for All Americans." Circulation 91(1995), 580.
• Beck, B. R. & Shoemaker, M. R. Osteoporosis: Understanding key risk factors and therapeutic options. Physician and Sportsmedicine. 28(2), 67-81, 2000.
• Biddle, S. "Exercise and Psychosocial Health." Research Quarterly for Exercise and Sport 66(1995):292.
• Blair, S., et al. "Physical Activity and Health: A Lifestyle Approach." Medicine, Exercise, Nutrition and Health 1(1992):54.
• Blair, S.N., and R.S. Paffenbarger. "Physical Activity and Risk of Cancer." (ab.) Medicine and Science in Sports and Exercise 19(1987):418.
• Brill, P. A., Macera, C. A., Davis, D. R. Blair, S. N., & Gordon, N. Muscular strength and physical function. Medicine and Science in Sports and Exercise. 32(2), 412-416, 2000.
• Bouchard, C., et al., eds. Physical Activity, Fitness, and Health. Champaign, IL: Human Kinetics Publishers, 1994.
• Campaigne, B. N. Exercise and Type I Diabetes. ACSM's Health and Fitness Journal .2(4)(1998):35.
• Chambers, M. "Exercise: A Prescription for a Good Night's Sleep?" Physician and Sportsmedicine 19(1991):107.
• Chandrasheckhar, Y., et al. "Exercise as a Coronary Protective Factor." American Heart Journal 122(1991):1723.
• Corbin, C.B., & R. P. Pangrazi. "The Health Benefits of Exercise." Research Digest for Physical Activity and Fitness 1(1993):1.
• Corbin, C. B. & R. P. Pangrazi, R. P. (ed).Towards a Better Understanding of Physical Fitness and Activity. Scottsdale, AZ: Holcomb-Hathaway, 1999, Sections II, III, and IV.
• Colberg, S. R. & Swain, D. P. Exercise and Diabetes Control. Physician and Sportsmedicine. 28(4), 63-81, 2000.
• Courneya, K. S., Mackey, J. R., & Jones, L. W. Coping With Cancer: Can exercise help? Physician and Sportsmedicine. 28(5), 49-74, 2000.
• Dembo, L. & McCormick, K. M. Exercise prescription to prevent osteoporosis. ACSM's Health and Fitness Journal. 4(1), 32-38, 2000.
• Etnier, J. L. et al. The influences of physical fitness and exercise upon cognitive functioning: A meta analysis. The Journal of Sport and Exercise Psychology.. 19(3)(1997):249.
• Leutholtz, B. C. Exercise Can Reduce Incidence and Severity of Hypertension. ACSM's Health and Fitness. 2(5)(1998):36.
• Manilow, M. R., Bostom, A.G. & Krauss, R. M. Homocysteine, diet and cardiovascular disease: A statement for health care professionals from the nutrition committee of the American Heart Association, Circulation. 99(1), 178-182, 1999.
• Nieman, D. C. Exercise soothes arthritis: joint effects. ACSM's Health and Fitness Journal. 4(3), 20-28, 2000.
• Nieman, D. C. Moderate Exercise Boosts the Immune System. ACSM's Health and Fitness Journal.. 1(5)(1997):19.
• Ortal, M. & C. Sherman. Exercise Against Depression. The Physician and Sports Medicine. 26(10)(1998):55-60.
• Osness, W. H. Exercise and the Older Adult. Reston, VA: AAHPERD, 1998.
• Pescatello, L. S. Exercise Prescription and Management for Cardiopulmonary Health. ACSM's Health and Fitness Journal.. 3(2), 15-21, 1999.
• Physician and Sportsmedicine. Homocysteine and heart disease: A culprit or just a suspect? Physician and Sportsmedicine. 27(7), 13-16, 1999.
• Powell, K.E., et al. "Physical Activity and the Incidence of Coronary Heart Disease." Annual Review of Public Health 8(1987):253.
• Powell, K.E., et al. "Physical Activity and Chronic Diseases." American Journal of Clinical Nutrition 49(1989):999.
• Rejeski, W.J., et al. "Physical Activity and Health-Related Quality of Life." Exercise and Sport Sciences Reviews 24(1996):71.
• Shephard, R. J. & Shek, P. N. Exercise, immunity and susceptibility to infection. Physician and Sportsmedicine. 27(6), 47-71, 1999.
• U. S. Department of Health and Human Services. (1996). Physical Activity and Health: A Report of the Surgeon General.Atlanta, GA: U. S. Department of Health and Human Services, Chapter 6.
• Van Loan, M. D. What Makes Good Bones: Factors Affecting Bone Health. ACSM's Health and Fitness Journal. 2(4)(1998):27.
• Vuori, I. "Exercise and Physical Health: Musculoskeletal Health and Functional Capacities." Research Quarterly for Exercise and Sport 66(1995):276.
• Whaley, M. H. et al. Physical fitnerss and clustering of risk factors associated with metabolic syndrome. Medicine and Science in Sports and Exercise. 31(2), 287-293, 1999.
• Wells, C. L. Physical activity and Cancer prevention: Focus on Breast Cancer. ACSM's Health and Fitness Journal. 3(1), 13-18, 1999.
• Wilmore, J. H. Exercise, Obesity and Weight Control. In Corbin, C. B. & Pangrazi, R. P. (ed.). Towards a Better Understanding of Physical Fitness and Activity. Scottsdale, AZ: Holcomb-Hathaway, 1999, Chapter 16.
• Youngstedt, S. D. Does Exercise Truly Enhance Sleep? Physician and Sportsmedicine. 25(10)(1997):72.