Diabetes is a metabolic disease characterized by chronic high blood sugar and Diabetes is the 7th leading cause of death in America and prevalence rates have …
Web Review - Concept 06
The Health Benefits of Physical Activity
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Web06-01: Actual Causes of Death in the United States p 77
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 recently 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 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 Based on these figures, many scientists
have concluded that physical inactivity has 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:
References:
McGinnis, JM, Foege, WH 1993 Actual causes of death in the United
States Journal of the American Medical Association 270, 2207-2212
The Surgeon Generals Report on Physical Activity and Health:
http://wwwcdcgov/nccdphp/sgr/sgrhtm
Web06-02: Cholesterol and the Atherosclerotic Process p 80
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 cigarrettes
all cause some damage to the vessels The immune
system responds to heal the area but makes the area stickyby 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 Exercise is known to reduce this buildup primarily by
decreasing cholesterol and blood pressure
A recent study in the Journal of the American Medical Association Smith et
al, 1999 has shown that exercise also 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 likely mechanism for the preventive benefits of physical
activity on coronary heart disease
Source:
Smith et al 1999 Long-term exercise and atherogenic activity of blood
mononuclear cells in persons at risk of developing ischemic heart disease
Journal of the American Medical Association, 28118, 1722-1727
The American Heart Association wwwamericanheartorg has a number of
excellent resource documents to help people understand the effect of
cholesterol on
decreasing their risks of heart disease Click here to get
more specific information about cholesterol The American Heart Association
also offers a program called Cholesterol Low Down that provides behavioral
strategies and tips through monthly emails to help you lower your
cholesterol levels The program is a free service of the AHA that is
sponsored by Pfizer Inc
Web06-03: Homocysteine and the Atherosclerotic Process p 80
A number of biological markers have been found that indicate an increased
risk for heart attacks and strokes A substance that is currently getting a
lot of attention is homocysteine Like other risk factors, the risk from
homocysteine appears to be moderated by a healthy lifestyle The
information below provides some basic information about homocysteine
Individuals interested in further details should consult some of the
references listed below
What is Homocysteine?
Homocysteine is an amino acid produced by the body that is involved in the
metabolism of other amino acids
Why is Homocysteine dangerous?
Homocysteine is toxic to the endothelial cells that line the arteries It
also promotes the oxidation of LDL cholesterol Both factors cause plaque
to form in
the arteries leading to atherosclerosis
Can Homocysteine be reduced?
Yes, another substance available in foods folic acid converts
homocysteine into a harmless amino acid methionine In fact, folic acid
levels are a good predictor of homocysteine levels Individuals with low
folic acid levels tend to have higher homocysteine levels
How can you increase folic acid levels?
Folic acid can be found in a variety of foods but it is especially high in
green vegetables and legumes beans and nuts Individuals eating these
foods probably meet the current RDA of 200 ug/day or the USRDA of 400
ug/day Individuals should try to obtain this nutrient through their diet
but if not possible a supplement may be considered See Table below to see
foods high in folic acid
Note: The FDA has recently mandated that all enriched grain/cereal
products be fortified with folic acid The primary reason for this is the
documented effect of folic acid supplementation on reducing the risk of
neural tube birth defects Because the folic acid is needed within the
first month of pregnancy, the supplementation helps to ensure that most
women have sufficient amounts The supplementation should also contribute
to
lowering homocysteine levels The American Heart Association provides
additional information about homocysteine
Web06-04: Exercise and High Blood Pressure p 82
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 strokeBecause of the strong
links to heart disease and stroke, increasing awareness about hypertension
is a major goal of the American Heart Association AHA They offer a
number of resources to help people learn more about hypertension
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
Web06-05: Peripheral Vascular Disease p 83
Peripheral vascular disease is a form of atherosclerosis in the
extremities Atherosclerosis refers to a
progressive blockages in arteries
that is created when fatty substances build up inside the artery walls over
time and cause a narrowing of the artery See Web06-02 The buildup
inhibits blood flow to the affected region In the peripheral vessels, this
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 diagram below shows a cross section image of how plaque
may build up within the arteries
The American Heart Association wwwamericanheartorg has a variety of
resources on reducing risk for heart disease and peripheral vascular
disease Click on the link to learn more about peripheral vascular disease
Web06-06: Physical Activity and Cancer p 83
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
Web24-02 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 Effects of Physical Activity and Cancer
A number of studies have linked physical inactivity with cancer The
Surgeon Generals Report provides a detailed review of the evidence
currently available to support links between physical activity and
different site-specific cancers The Report indicates that there is strong
evidence to support a beneficial effect for colo-rectal cancer but no
association for rectal cancer Data for breast, endometrial, ovarian,
prostate, and testicular cancers were too limited or inconclusive to
support any firm conclusions They pointed out that physical activity in
adolescence and early adulthood may protect against future risk of breast
cancer and recommended further research on the topic
Additional information on physical activity and cancer can be found at the
American Cancer Society website wwwcancerorg
Web06-07: Physical Activity and Diabetes p 83
Diabetes is a metabolic disease characterized by chronic high blood sugar
and insufficient
insulin secretion or utilization See Web24-02 Diabetes
is the 7th leading cause of death in America and prevalence rates have
increased dramatically in recent years The American Diabetes Association
wwwdiabetesorg estimates that there are 157 million people or 59 of
the population in the United States who currently have diabetes While an
estimated 103 million have been diagnosed, unfortunately, 54 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 bodys 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
The Effects of Physical Activity on Diabetes
Physical activity can significantly reduce a persons risk of diabetes and
also help current diabetics by reducing insulin requirements The Surgeon
Generals 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
Information on oral glucose tolerance tests used to diagnose diabetes is
provided on Web24-03
Additional information on physical activity and diabetes can be found at
the American Diabetes Association website wwwdiabetesorg
Web06-08: Physical Activity and Osteoporosis p 84
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 The pictures below show microscopic images of healthy bone left
and less dense osteoporotic bone right
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 15 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
Effect of Physical Activity on Reducing Risks of Osteoporosis
A number of controlled trial studies have reported that bone mineral
density bmd is improved with weight bearing exercise On the graph the
points that fall above the diagonal line represent studies in
which the
treatment group exercise was better than the control group non-
exercise The fact that more points are above the line provides strong
evidence that physical activity can increase bone mineral density and
reduce the associated risks of osteoporosis
For further information on osteoporosis, visit the National Osteoporosis
Foundation at wwwnoforg
Web06-09: Functional Disability and Aging p 86
By the year 2025, approximately 25 of the population in the US 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 The fact that disability rates have begun decreasing
among the elderly is evidence that healthy lifestyles are having a positive
benefit for many elderly individuals Additional efforts are needed to
reduce the potential health risks among the elderly
Source: US Census Bureau
A recent report highlights objectives and strategies to promote physical
activity among the fast growing elderly
population The report called the
National Blueprint: Increasing Physical Activity Among Adults Aged 50 and
Older, recognizes the important health issues associated with the expanding
geriatric population and the important role that physical activity can have
in promoting improved health The report was a combined effort by a number
of professional organizations including AARP, the American College of
Sports Medicine, the American Geriatrics Society, the Centers for Disease
Control and Prevention, The National Institute on Aging, and The Robert
Wood Johnson Foundation Information on the report is summarized in a media
release and the available from the Robert Wood Johnson Foundation
wwwrwjforg
Web06-10: Activity and Aging p 86
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 results of several recent
studies among the elderly are described below
In one study 1, a cohort of middle-aged and older men n 3495
and
women n1175 from the Aerobic Center Longitudinal Study were followed up
for an average of 55 years to examine the effect of fitness on the
prevalence of functional limitations The results showed a clear
association with higher levels of fitness associated with lower prevalence
of functional limitations see graph below An interesting finding in the
study was that a lower percentage of high fit men in their 60s reported
limitations than low fit participants in their 50s This suggests that
physical activity and physical fitness can somewhat counteract the typical
deterioration of physical function that occurs with age
Another recent study 2 examined the effect of physical activity on the
commonly observed decline in cognitive function with age This study
involved a cohort of 347 elderly Dutch men with a mean age of 75
Individuals in the less active group had a two fold greater risk of
cognitive impairment than individuals in the more active group The authors
identified a specific genetic marker that may increase the risk of decline
in some individuals but physical activity was viewed as an important
intervention strategy to maintain function in the elderly
References cited:
1
Huang, Y, Macera, CA, Blair, SN, Brill, PA, Kohl, HW,
Kronenfeld, JJ 1998 Physical fitness, physical activity, and
functional limitation in adults aged 40 and older
2 Schuit, AJ, Feskens, EJM, Launer, LJ, Kromhout, D 2001
Physical activity and cognitive decline, the role of the
apolipoprotein e4 allele Medicine and Science in Sports and Exercise
335, 772-777
Web06-11: Hyperkinetic Conditions p 89
Hyperkinetic conditions refer to problems that can occur from too much
exercise While some exercise-related injuries can occur from an acute
trauma or fall, many perhaps even the majority are associated with
overuse A common injury from overuse is a strained muscle or tendon Like
ankle sprains See Web03-08, these are graded on a 1,2, or 3 scale with a
3 being the most severe injury The graphic below shows a strain to the
quadriceps tendon A more common site for a muscle strain is the hamstring
since the quadriceps are usually stronger and can overpower the hamstring
during sprinting or high-intensity activities
Graphic provided with permission: Athletic Injury Assessment by Booher and
Thibodeau, 1994
Another relatively common
overuse injury among runners is stress fractures
in the bones of the lower leg This area takes considerable pounding during
high-level training and if proper time is not provided for recovery stress,
small cracks or stress fractures in the bone can form A study done in the
military indicated that approximately 85 of the new recruits suffered
stress fractures during the grueling 8-week basic training regimen that
they undergo upon enlistment A variety of factors were found to influence
risk Most noteworthy was that a history of regular exercise was protective
against stress fracture, and a longer history of exercise further decreased
the relative risk of fracture This suggests that regular, progressive
exercise can build up the strength and integrity of joints and possibly
reduce the risk of injury The information provided here is only for
general interest and are not to be used for diagnostic purposes
Individuals with some form of athletic injury are encouraged to seek
professional assistance to assist in diagnosing and treating their injury
Reference cited:
Lappe JM, Stegman MR, Recker RR 2001 The impact of lifestyle factors on
stress fractures in female Army recruits Osteoporos
Int 2001;121:35-42
We06-12: Supplemental Readings p 90
ACSMs Health and Fitness Journal 221998: 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,
3061998:975
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, 306,1998:992
American Heart Association A Statement on Exercise: Benefits and
Recommendations for Physical Activity Programs for All Americans
Circulation 911995, 580
Beck, B R Shoemaker, M R Osteoporosis: Understanding key risk
factors and therapeutic options Physician and Sportsmedicine 282, 67-
81, 2000
Biddle, S Exercise and Psychosocial Health Research Quarterly for
Exercise and Sport 661995:292
Blair, S, et al Physical Activity and Health: A Lifestyle Approach
Medicine,
Exercise, Nutrition and Health 11992:54
Blair, SN, and RS Paffenbarger Physical Activity and Risk of
Cancer ab Medicine and Science in Sports and Exercise 191987:418
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 322, 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 ACSMs Health and Fitness
Journal 241998:35
Chambers, M Exercise: A Prescription for a Good Nights Sleep?
Physician and Sportsmedicine 191991:107
Chandrasheckhar, Y, et al Exercise as a Coronary Protective Factor
American Heart Journal 1221991:1723
Corbin, CB, R P Pangrazi The Health Benefits of Exercise
Research Digest for Physical Activity and Fitness 11993:1
Corbin, C B R P Pangrazi, R P edTowards 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 284, 63-81, 2000
Courneya, K S, Mackey, J R, Jones, L
W Coping With Cancer: Can
exercise help? Physician and Sportsmedicine 285, 49-74, 2000
Dembo, L McCormick, K M Exercise prescription to prevent
osteoporosis ACSMs Health and Fitness Journal 41, 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 1931997:249
Leutholtz, B C Exercise Can Reduce Incidence and Severity of
Hypertension ACSMs Health and Fitness 251998:36
Manilow, M R, Bostom, AG Krauss, R M Homocysteine, diet and
cardiovascular disease: A statement for health care professionals from
the nutrition committee of the American Heart Association, Circulation
991, 178-182, 1999
Nieman, D C Exercise soothes arthritis: joint effects ACSMs Health
and Fitness Journal 43, 20-28, 2000
Nieman, D C Moderate Exercise Boosts the Immune System ACSMs Health
and Fitness Journal 151997:19
Ortal, M C Sherman Exercise Against Depression The Physician and
Sports Medicine 26101998:55-60
Osness, W H Exercise and the Older Adult Reston, VA: AAHPERD, 1998
Pescatello, L S Exercise Prescription and Management for
Cardiopulmonary
Health ACSMs Health and Fitness Journal 32, 15-21,
1999
Physician and Sportsmedicine Homocysteine and heart disease: A culprit
or just a suspect? Physician and Sportsmedicine 277, 13-16, 1999
Powell, KE, et al Physical Activity and the Incidence of Coronary
Heart Disease Annual Review of Public Health 81987:253
Powell, KE, et al Physical Activity and Chronic Diseases American
Journal of Clinical Nutrition 491989:999
Rejeski, WJ, et al Physical Activity and Health-Related Quality of
Life Exercise and Sport Sciences Reviews 241996:71
Shephard, R J Shek, P N Exercise, immunity and susceptibility to
infection Physician and Sportsmedicine 276, 47-71, 1999
U S Department of Health and Human Services 1996 Physical Activity
and Health: A Report of the Surgeon GeneralAtlanta, GA: U S Department
of Health and Human Services, Chapter 6
Van Loan, M D What Makes Good Bones: Factors Affecting Bone Health
ACSMs Health and Fitness Journal 241998:27
Vuori, I Exercise and Physical Health: Musculoskeletal Health and
Functional Capacities Research Quarterly for Exercise and Sport
661995:276
Whaley, M H et al Physical fitnerss and clustering of risk
factors
associated with metabolic syndrome Medicine and Science in Sports and
Exercise 312, 287-293, 1999
Wells, C L Physical activity and Cancer prevention: Focus on Breast
Cancer ACSMs Health and Fitness Journal 31, 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 25101997:72
———————–
Major Dietary sources
of Folic Acid
Black Eyed Peas
Beans kidney, pinto, navy
Spinach
Asparagus
Broccoli
Beets
Sunflower Seeds
Atherosclerotic Plaque
