4 years.Minor issues are water retention in mus-
cles,muscle cramping,and overall body dehydra-
tion.Once a person stops taking creatine,water
retention and temporary muscle enlargement due to
that retention disappear.Since the long-term effects
of creatine use are unknown,however,potential
users should proceed with caution.
Dehydroepiandrosterone (DHEA) is the body’s most
common hormone and acts as a weak steroid chemi-
cal messenger (a conveyor of internal control signals
and information).Although DHEA occurs naturally
in the body,manufacturers produce and sell it as a
supplement in a synthetic concentrated form despite
no deﬁnitive proof of its safety or effectiveness.
DHEA proponents claim that it increases muscle
mass and strength,lowers body fat,alters natural
hormone levels,slows aging,and boosts immune
functions.Despite manufacturers’ claims,research
studies have produced some conﬂicting results on
DHEA but overall do not provide strong evidence of
a large positive effect on muscle mass and strength,
or on body fat levels.
Androstenedione (nickname “andro”) is another
naturally occurring steroid hormone with a struc-
ture related to both DHEA and testosterone.It is
found naturally in meats and some plants.Even
though manufacturers claim “andro”will increase
testosterone levels,one pivotal study found that it
actually lowers the body’s natural production of
testosterone,did not increase the body’s adaptations
to resistance training,and increased heart disease
risk in men.
Androstenedione was ordered off the
market by the FDA in 2004,and its use is dwin-
dling.Both DHEA and androstenedione appear to
decrease HDL or “good”cholesterol,
explain why these substances increase heart attack
risks and other cardiovascular problems.Both also
increase the risk of developing certain cancers and
accelerating the growth of existing cancers.These
serious side effects strongly argue against the use of
DHEA or “andro.”
Your body’s pituitary gland produces human growth
hormone (GH),which promotes bone growth and
muscle growth and decreases fat stores.Drug manu-
facturers produce GH synthetically for medical use
steroids increase the risk of liver and heart disease,
cancer,acne,breast development in men,and mas-
culinization in women.Anabolic steroid use can also
promote connective tissue and bone injuries because
dramatically stronger muscles may exert more force
than the body can handle.Steroid use can also be
habit forming,lead to other drug addictions,and
even cause death,as explained in the box Spotlight:
Behind the Steroid Warnings.
Steroid use is relatively high among young ath-
letes in certain sports.Public awareness is continuing
to increase along with media coverage of steroid scan-
dals in the sports world.In 2005,for example,a
series of congressional hearings investigated steroid
usage in major league baseball.Members of Congress
examined the adequacy of drug testing and the
impact of steroid use by professional sports ﬁgures on
impressionable teenagers.Most of the baseball play-
ers called before the committee denied using steroids,
but popular player José Canseco stated that steroids
were “as prevalent in ...the late 1980s and 1990s as
a cup of coffee.”A 2005 survey of drug use among U.S.
adolescents reported that steroid use is down signiﬁ-
cantly among 8th and 10th graders from its peak in
2000 and has declined among 12th graders from its
peak in 2004.
Creatine is a legal nutritional supplement contain-
ing amino acids.It is most often sold as creatine
monohydrate in powder,tablet,capsule,or liquid
form.The body’s natural form of creatine (phospho-
creatine) is generated by the kidneys and stored in
muscle cells.You can also consume creatine in the
diet by eating meat products.
Creatine taken at recommended levels can
improve performance by temporarily increasing
the body’s normal muscle stores of phosphocrea-
tine.Since this natural energy substance powers
bursts of activity lasting less than 60 seconds,cre-
atine users sometimes find they can train more
effectively in power activities and may be able to
maintain higher forces during lifting.This can
result in increased training adaptations such as
strength and muscle size.Creatine intake also
causes a temporary retention of water in muscle
tissue that produces a small temporary increase in
size,strength,and ability to generate power.Crea-
tine has no effect on performance of aerobic
So far,there have been few serious side effects
reported in studies of people using creatine for up to
BUILDING MUSCULAR STRENGTH AND ENDURANCE
GET FIT,STAY WELL!
the human brain. The same may be true of a region
that produces serotonin and is involved in depres-
sion. Such changes during teenage brain develop-
ment could mean lifelong changes in a person’s
aggression and depression levels, even after he or
she stops using steroids.
5. Steroids disrupt the way the body processes
cholesterol. As a result, steroids promote heart
disease, heart attacks, and strokes, even in athletes
younger than 30. The liver and kidneys must
detoxify and remove steroids from the body, and
both organs are more prone to cancerous tumors
in steroid users. The drugs also cause blood-ﬁlled
cysts in the liver that can burst and cause serious
6. Injecting steroids, rather than taking them orally,
and sharing needles with other users can lead to
dangerous infections transmitted through dirty
needles. The disease risks include hepatitis; HIV;
and endocarditis, a bacterial infection of the heart.
American Psychological Association (APA). “Animal Models
Show that Anabolic Steroids Flip the Adolescent Brain’s
Switch for Aggressive Behavior.” Press release. February 26,
Grimes, J. M. et al. “Plasticity in Anterior Hypothalamic
Vasopressin Correlates with Aggression during
Anabolic-Androgenic Steroid Withdrawal in Hamsters,”
Behavioral Neuroscience120, no. 1 (2006): 115–124.
National Institute on Drug Abuse (NIDA). Research Report
Series—Anabolic Steroid Use. September–November, 2006.
BEHIND THE STEROID WARNINGS
The National Institute on Drug Abuse (NIDA) publishes
two postcards for young men and women with a
potent message on the dangers of anabolic steroids.
Each card lists the risks and side effects of steroid use,
ranging from cancer and heart disease to HIV infec-
tion, behavioral problems, and unwelcome body
changes. Why are government drug regulators—not
to mention parents, educators, and coaches—so
worried about steroid use in young people?
Steroid use in teens and young adults is a problem
for several major reasons:
1. Use of these drugs is surprisingly common. More
than half a million 8th and 10th graders have used
anabolic steroids, as have tens of thousands of
high school seniors. According to NIDA, steroid use
is also “probably widespread among athletes and
would-be sports competitors at all levels.”
2. Steroid use can lead to the abuse of other drugs.
Some of the side effects of steroid use—insomnia,
fatigue, restlessness, depression—are so disruptive
that people turn to opiate drugs such as cocaine
and heroin to relieve their distress.
3. Anabolic steroids can permanently disrupt normal
development. A person’s body and brain are still
developing during adolescence and into their early
20s. Steroids interfere with the normal maturational
effects of sex hormones. In males, this interference
can shrink the testes and reduce sperm production,
stunt normal height, induce breast development,
and cause baldness. In females, steroids can reduce
breast size, deepen the voice, and induce excessive
body hair growth while thinning the head
hair. Most of these changes are irreversible.
4. Steroid use can lead to behavioral changes,
including irritability, hostility, aggression,
and depression. Researchers injected adoles-
cent hamsters with commonly used steroids,
then observed as their playful ﬁghting—
wrestling and nibbling—turned to outright
attacking and biting at levels 10 times
higher. This aggression went on even after
the drugs were withdrawn and stayed
throughout half of the hamsters’ remaining
adolescence. The researchers found
increased levels of a neurotransmitter called
vasopressincoming from one brain region
that closely resembles the same structure in
BUILDING MUSCULAR STRENGTH AND ENDURANCE
in children and young adults with abnormally slow
or reduced growth and related disorders.Although
the FDA regulates growth hormone,athletes want-
ing to gain an edge over their competitors sometimes
obtain and use it illegally.Marketers claim that
growth hormone supplementation will counteract
the muscle mass lost with disuse and aging,among
other alleged beneﬁts.However,GH side effects
include irreversible bone growth (acromegaly/
gigantism);increased risk of cardiovascular
diseaseand diabetes;and decreased sexual desire,
Marketers of oral GH supplements (GH promot-
ers,not actual GH) claim the same positive beneﬁts
to lean muscle mass and fat mass,but this is not
borne out in tests or actual use.Oral GH,in fact,
cannot even be absorbed from your digestive tract
into your bloodstream! A far better way to increase
natural levels of growth hormone is to perform
regular exercise.In a study of women who ran for
exercise,baseline resting GH levels increased by
50percent in those training at higher compared to
Many bodybuilders and weight lifters take amino acid
supplements because they believe that consuming
protein or its building blocks (amino acids) will lead to
enhanced muscle development.However,evidence is
mixed that high intake of protein or taking protein-
based supplements will improve training,exercise
performance,or build muscle mass beyond the levels
achieved through normal dietary protein.When com-
bined with resistance training,moderate increases in
protein intake may lead to small increases in lean
muscle mass and strength beyond resistance training
In contrast,supplementation with the amino
acid glutamine produced no beneﬁcial effect above
and beyond resistance training itself.
ate doses of these supplements has no dramatic side
effects,but large doses of either the supplements or
protein itself can create amino acid imbalances,alter
protein and bone metabolism,and be dangerous to
individuals with liver or kidney disease.
1. How would you answer Gina’s questions about
steroids and creatine?
2. Give two other examples of ergogenic
supplements. How safe are they?
3. Have you ever taken an ergogenic supplement? If
so, how much do you know about the pros and
cons of taking that supplement?
“I’m a big baseball fan. Growing up in San Francisco,
Iused to go to Giants and A’s games all the time. So
Iwas kind of shocked to hear about the allegations of
steroid and drug use among professional baseball
players. I’m confused about the health risks of steroids
and supplements. Are they all dangerous? What about
the products you can buy in a health store, like
GET FIT,STAY WELL!
CRITICAL THINKING QUESTIONS
1. Why is weight training a popular activity among
college students and adults of all ages?
2. Deﬁne sarcopeniaand discuss how it can be reversed
through exercise.How are sarcopenia and atrophy
3. Which ﬁber type is activated most during a sprint?
What is the predominant ﬁber type in the postural
1. Muscular strength is the ability to
a.contract your muscles repeatedly
b.run a 6-minute mile.
c. look “toned”in a swimsuit.
d.contract your muscle with
2. Which of the following beneﬁts of resistance
training will reduce your risk of cardiovascular
a.Increased bone density
b.Increased muscle power
c. Reduced body fat levels
d.Better sports recovery
3. What is a single muscle cell called?
4. Which of the following will result in a stronger
a.Eating more protein before your
c. Taking DHEA before your
d.Activating more motor units
5. Sitting down in a chair and standing up again is an
example of this type of exercise:
4. Discuss the role of resistance training in preventing
5. How does circuit weight training differ from regular
weight training? What are the speciﬁc beneﬁts of
doing circuit weight training?
6. Muscle strength improvements in the ﬁrst few weeks
of a program are due to:
a.Increased size of muscle ﬁbers
b.Increased activation and coordination of motor units
c. Increased ability of muscles to move through a full
range of motion
d.Increased blood ﬂow to working muscles
7. A good test of muscular endurance includes
a.a 1 RM test.
b.a grip-strength test.
c. a 20 RM test.
d.a pull-up test.
8. One disadvantage of using machines for resistance-
training exercises is
a.the machine takes time to adjust for your height
and desired resistance level.
b.the machine does not promote the use of postural
and stabilizing muscles during the exercise.
c. spotters are needed.
d.it can be hard to isolate speciﬁc muscle groups.
9. Which of the following is NOT part of the criteria you
should use when selecting a personal trainer?
a.Certiﬁed by ACSM,NSCA,or ACE
b.Good references by former and current clients
c. Number of years in the ﬁeld
d.The number of dietary supplements they can help
you obtain at a reduced cost
10. Which of the following supplements/drugs have
irreversible bone growth,cardiovascular disease,
diabetes,and decreased sexual desire among its
negative side effects?
c. Growth hormone
CHAPTER IN REVIEW
Documents you may be interested
Documents you may be interested