Transcript Figure 16.1 - Rowan University

Chapter 16
Exercise Risks
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Musculoskeletal Injuries
See Figure 16.1 for a summary of emergency
room visits for a variety of sports.
Running injuries
The 1-year injury incidence rate for runners varies
from 2-77% or 2.5-12 injuries/1000 hrs running.
Figures 16.3 and 16.5 show that injury rates among
runners tend to rise with increase in weekly running
mileage.
Figure 16.4 shows that the knee and foot are the most
common injury sites.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Performance
Figure 16.7 Overtraining syndrome. See Box 16.1.
1
0.5
0
-0.5
-1
-1.5
-2
-2.5
-3
-3.5
-4
Normal
Below normal
Poor
1
2
3
4
5
6
7
8
9 10 11 12
Weeks
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Figure 16.10
Management of overuse injuries---also see Box 16.2 for a
functional approach to injuries and pain that offers athletes
the best chance for recovery from injury.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Female Athlete Triad
The syndrome of disordered eating (and excessive
exercising), amenorrhea, and osteoporosis is
called the female athlete triad (Figure 16.11). See
Box 16.3 for a summary. See Figure 16.13 for
graph comparing bone mineral mass among
different groups.
The causes of menstrual dysfunction are still hotly
debated but may be related to alterations in sex
hormones and energy drain.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Figure 16.11 Female athlete triad
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Figure 16.13
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise and Pregnancy
Moderate amounts of exercise during pregnancy
are recommended for the health and fitness of the
mother and baby.
Debate still centers on whether intense and
prolonged exercise by the pregnant mother can
cause harm to the growing fetus.
See Box 16.4 for ACOG guidelines for exercise
during pregnancy.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Heat Injuries
See Box 16.5 for risk factors of heat illness.
See Box 16.6 for ACSM recommendations for
race events.
Heat cramps
Heat exhaustion
Heat stroke
Exertional rhabdomyolysis
Measuring temperature for exercise risk (see
Figure 16.14)
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Environmental Pollution
Air pollution and ill health – see Box 16.7 for air quality index
standards
Primary air pollutants
Carbon monoxide
Sulfur dioxide
Nitrogen oxide
Particulate matter
Secondary air pollutants
Ozone
Sulfuric acid
Nitric acid
Peroxyacetyl nitrate
Exercise and ozone – see Figure 16.15
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Sudden Death
From Heart Attack
Is there a risk of dying of a heart attack during exercise?
Yes, but most people over age 30 who suffer a heart attack during
or after vigorous exercise are at high risk for CHD, and then
exercise too hard for their fitness level, triggering the final heart
attack event (see Figure 16.17).
When a young athlete dies during or shortly after exercise, it is most often
due to a birth defect of the cardiovascular system (see Figure 16.16).
If an individual is at low risk for heart disease, has not experienced
any symptoms, and exercises moderately, risk is extremely low,
and overall, heart disease risk should be lowered because of the
regular exercise program. See Figure 16.19.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise and the Common Cold
People who exercise regularly report fewer colds than their
sedentary peers. Numerous surveys indicate that 60%-90% of
physically active individuals perceive themselves as less
vulnerable to viral illnesses than those who are inactive.
Several randomized studies support the viewpoint that near-daily
physical activity reduces the number of days with sickness.
In these studies, subjects in the exercise groups walked briskly 35-45
minutes, five days a week, for 12-15 weeks during the winter/spring or fall,
while the control groups remained physically inactive. The results were in
the same direction reported by fitness enthusiasts--walkers experienced
about half the days with cold symptoms of the sedentary controls.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise Benefits to the Immune System
During moderate exercise, several positive changes occur in the
immune system.
Stress hormones, which can suppress immunity, are not elevated during
moderate exercise.
Immune cells increase recirculation.
Although the immune system returns to pre-exercise levels very quickly after the
exercise session is over, each session represents a boost that appears to reduce
the risk of infection over the long term.
Although public health recommendations must be considered
tentative, the data on the relationship between moderate exercise and
lowered risk of sickness are consistent with guidelines urging the
general public to engage in near-daily brisk walking and other forms
of moderate physical activity.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise and Immunity
Among elite athletes and their coaches, a common
perception is that heavy exertion lowers resistance
to colds.
The immune systems of athletes have been studied
under laboratory conditions before and after
exercising intensely for 2-4 hours. A steep drop in
immune function occurs which lasts 1 to 3 days.
Much of this immune suppression appears to be
related to the elevation of stress hormones which
are secreted in high quantity during and following
heavy exertion. This allows viruses to spread and
gain a foothold.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise and Immunity
The relationship between exercise, infection, and
immune function (often called immunosurveillance)
is given in Figure 16.21).
This model shows that although the risk of infection may
decrease below that of a sedentary individual when one
engages in moderate exercise training, risk may rise
above average during periods of excessive amounts of
high-intensity exercise.
Immunosurveillance is enhanced during moderate
exercise training, but during unusually heavy training, it
is suppressed.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Figure 16.21
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Concerning exercising when sick:
If one has common cold symptoms (e.g., runny nose and
sore throat without fever or general body aches and
pains), moderate physical activity can be continued.
However, wait a few days after the resolution of
symptoms before exercising vigorously.
With symptoms of fever, extreme tiredness, muscle
aches, and swollen lymph glands (e.g., the flu), rest and
avoid all exercise. Once the symptoms are gone,
gradually return to a regular program of exercise, and
allow 2-4 weeks before resumption of intensive training.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
What Is Asthma?
Asthma [Greek “to pant”] is an inflammation of the lungs which
causes airways to narrow, making it difficult to breathe. See
Figure 16.22.
Inflammation makes the airways sensitive to allergens, chemical irritants,
tobacco smoke, cold air, or exercise.
When exposed to these stimuli, an asthma attack can occur, causing the
muscles around the windpipes to tighten, making the opening smaller.
The lining of the windpipe swells (becomes inflamed), and produces mucus.
This leads to coughing, wheezing, chest tightness, and difficulty in
breathing, particularly at night or in the early morning.
Asthma symptoms come and go; they can last for a few moments
or for days. Asthma attacks can be mild or severe and sometimes
fatal. Each year in America, more than 5,000 people die from
asthma, with rates twice as high among blacks compared to
whites. See Box 16.8.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Prevalence of Asthma
Asthma is a major public health problem, affecting more
than 100 million people worldwide and five percent of
Americans (about 17 million).
In the United States, about one child in every 15 has asthma.
During the 1980s, for unknown reasons, asthma rates rose 49
percent, a problem now recognized in many other nation
worldwide.
This may be linked to factors including housing with reduced
ventilation, exposure to indoor allergens (such as domestic dust
mites in bedding, carpets, and stuffed furnishings, and animals
with fur, especially cats), tobacco smoke, viral infections, air
pollution, and chemical irritants.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Asthma Prevention
Guidelines
Asthma episodes can be prevented, but it is
unknown if development of the underlying
inflammatory disease can be averted.
Inflammation makes the airways hypersensitive to a
wide variety of irritants.
Causes of the initial tendency toward inflammation in
the airways are not yet known for certain, but one of
the strongest risk factors is an inherited tendency to
have allergic reactions.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Asthma Prevention Guidelines
The common triggers include:
House dust mites:
These are often a major component of house dust, and feed on human
skin sheddings. Hot laundering, airtight covers, removal of carpets, and
avoiding fabric-covered furniture are recommended.
Animal allergens from animals with fur:
These include small rodents, cats, and dogs, and can trigger asthma.
Animals should be removed from the home.
Tobacco smoke:
Is a trigger whether the patient smokes or breathes in the smoke from
others.
Cockroach allergen:
A common trigger in some locations. Infested homes should be cleaned
thoroughly and regularly.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Asthma Prevention
Guidelines
Mold and other fungal spores and pollens:
These are particles from plants. Windows and doors should be closed,
and those with asthma are recommended to stay indoors when pollen
and mold counts are highest. Air conditioning can be helpful.
Smoke from wood-burning stoves and other indoor air
pollutants:
Produce irritating particles. Vent all furnaces and stoves to the
outdoors, and keep rooms well ventilated.
Colds or viral respiratory infections:
Can trigger asthma, especially in children. Give an influenza
vaccination every year to patients with moderate to severe asthma. At
the first sign of a cold, use asthma medications to control symptoms.
Physical activity:
A common trigger for most people with asthma.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise-Induced Asthma (EIA)
EIA is triggered as the lining cells of the airway are cooled and dried during
exercise.
As air is taken into the lungs, it is warmed and humidified, resulting in a cooling and
drying of the airway lining.
Certain chemicals are then released by the lining cells, causing the airways to
tighten.
This cooling and drying is worsened by several factors, including exercising in cool
and dry air, a switch from nasal to mouth breathing, and fast and deep breathing
from intense exercise.
If pollutants and pollen are in the air, the risk of EIA is increased.
EIA symptoms are most severe within five to 10 minutes after exercise.
The EIA attack generally lasts five to 15 minutes, and symptoms gradually diminish
within 45 to 60 minutes.
If the individual exercises again within 30 to 90 minutes of the first bout, the airway
tightening is markedly less, and fewer EIA symptoms are experienced.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Figure 16.23
Pattern of EIA
EIA goes through at least
3 phases:
Early phase response
Spontaneous recovery
Refractory period
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise Testing
In the exercise laboratory, EIA is diagnosed if
the ability to exhale a certain amount of air from the lungs
quickly (within one second) falls by 15 percent or more
following six to eight minutes of high intensity exercise (90
percent of the maximal heart rate).
Many asthmatics now use peak flow meters which are small
devices that measure how well air moves out of the airways.
Asthmatics should avoid exercising vigorously until the peak
flow reading returns or exceeds 80 percent of the personal best
peak flow reading.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Asthma Treatment
Although asthma cannot be cured, it can be controlled by
establishing a lifelong management plan with a physician.
Individuals who follow their asthma management plans
and keep their asthma under control can usually participate
vigorously in the full range of sports and physical
activities.
Proper management of EIA, includes:
Monitoring air flow with a peak-flow meter.
Avoiding allergic triggers.
Using medication before exercise.
Modifying exercise habits and practices.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Medication
Drugs that relax the muscle spasm in the wall of the airways and
help to open them (e.g., bronchodilators) are often the first line of
treatment in preventing EIA.
Doctors recommend using the medication (typically beta2-agonist) from five
minutes to an hour before exercise.
Beta2-agonist medications will control EIA in more than 80 percent of
asthmatics, and are helpful for several hours.
Cromolyn sodium is often prescribed to treat athletes who have
EIA.
This drug, which is also an inhalant, prevents the lining of the airways from
swelling in response to cold air or allergic triggers.
Cromolyn sodium can be used up to 15 minutes before engaging in physical
activity.
Corticosteroids should be used as preventive medicine, usually on an
ongoing basis, to help control the underlying inflammation.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise Programming
In addition to proper medications, control of triggers, and
use of peak-flow meters, several modifications to the
exercise program have proven valuable:
Adequate warm-up and cool-down periods:
These help prevent or lessen episodes of EIA.
Type of exercise:
Outdoor running is closely linked with EIA, followed by treadmill
running, cycling, and walking.
Swimming rarely leads to EIA because warm and humid air near the
surface of the water prevents cooling and drying of the airways.
Length of exercise:
Long, intense, continuous exercise (e.g., running and cycling) causes
more EIA than repeated short bursts of exercise (generally less than five
minutes each).
Stop-and-go sports like tennis, volleyball, or football may lead to less
EIA for some asthmatics.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Exercise Programming
Intensity of exercise:
High intensity exercise (above 80-90 percent of the maximum heart rate)
causes more EIA than does exercise at more moderate levels (e.g.,
walking).
Nasal breathing:
Nasal breathing warms and humidifies the air better than breathing
through the mouth.
Wear a mask or scarf in cold weather:
This can increase the temperature and humidity of the inhaled air,
reducing cooling and drying of the airway lining.
Monitor the environment for potential allergens and
irritants:
Examples include a recently mowed field, refinished gym floor, smoke
in the air, or high pollen counts during a spring morning.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Benefits of Exercise Training
Despite the fact that exercise may trigger asthma, the
benefits that come from regular physical training are so
important that most asthma experts urge that it be
included as an important part of the management
strategy of the asthmatic.
Regular exercise improves the overall physical fitness level of
the individual with asthma, improves psychological mood
state, decreases the risk for other chronic diseases, and
improves heart and lung function.
Also, several researchers have shown that as the individual
with asthma becomes physically fit, EIA attacks are less
frequent.
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.
Figure 16.24
Nieman DC. Exercise Testing and Prescription: A Health-Related Approach. 6/e.
Copyright ©2007 McGraw-Hill Higher Education. All rights reserved.