Performance
Nutrition
by Kim Schoenhals
Every physical action, voluntary or involuntary, is
achieved through energy metabolism, or bioenergetics--the science of how
the body extracts energy from food. To create energy, the body converts
food into simpler compounds that are transported through the bloodstream
for use in individual cells. Carbohydrates are converted to glucose (sugar),
fats are converted to glycerol (a triglyceride) and fatty acids, and proteins
are broken down into amino acids. Once in the cells, these nutrients are
chemically transformed into the energy molecule adenosine triphosphate
(ATP) through a metabolic process known as Kreb's Cycle. Legal steroid
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ATP, which is produced in the mitochondria, is the basis for all energy
within the human system. The production of ATP is achieved through the
utilization of inherent and dietary nutrients such as vitamins, minerals
and amino acids. In addition to fueling the body's ability to create energy,
many nutrients--and botanicals--can enhance this process when taken as
supplements.
Performance nutrition is a multi-billion dollar market worldwide, and
sports nutrition consumers have more faith in supplements than the general
population. According to the Natural Marketing Institute's (NMI) The Health
& Wellness Trends Database--three years of trended data including
more than 2,000 national consumer households--80.2 percent of sports nutrition
supplement users believe vitamins and minerals are effective in preventing
and treating various health conditions, as compared to 74.5 percent of
the general population. In addition, 65 percent of athletes began using
sports supplements to enhance performance and energy, and 24 percent of
sports supplement users began taking supplements to improve overall health
and wellness.
Enhancing immune function is of particular concern to athletes because
exercise temporarily weakens the immune system.1 Vitamin, mineral and
botanical supplementation can combat this phenomenon.
While a healthy diet is the basis for efficient energy production, adding
supplements to a workout regimen can enhance ATP production, increase
energy, decrease recovery time and attenuate exercise-induced cramps and
muscle soreness, as well as preserve immune function that may suffer as
a result of strenuous exercise.
Vitamins Etc.
Lactic acid, or lactate, is the culprit responsible for muscle soreness
and cramping both during and following exercise. It is a natural compound
produced in the muscles during exercise, but when it accumulates in high
levels, it can cause cramps, spasms and soreness, as well as prolong recovery
time between workouts. While lactic acid buildup has a tendency to damage
muscle tissue, the body's natural antioxidant defense system protects
against that damage, according to researchers at Osmangazi University
in Eskisehir, Turkey.2
Antioxidants have been widely studied for their role in protecting muscle
tissue from free radical production that may occur during exercise, and
they are popular among athletes. For example, 30 percent of joggers and
28.1 percent of bodybuilders take antioxidants as compared to 16.4 percent
of the general population, according to NMI. There is some contention
that free radicals have the chance to damage muscle tissue during exercise,
as the body activates its own antioxidant defense system even as it produces
lactic acid. According to researchers at Toho University School of Medicine
in Tokyo, the increased serum antioxidant concentrations that occur during
anaerobic exercise prevent oxidative damage to skeletal muscle, even though
lactate levels also significantly increase after exercise.3
While there is disagreement that free radicals damage muscle tissue during
exercise, muscle soreness and cramping are a reality in the world of athletic
performance. Antioxidant vitamin C may be able to reduce exercise-related
muscle soreness in those who are unaccustomed to working out, according
to Dylan Thompson, Ph.D., and researchers from the University of Bath
in Swindon, England. They discovered that men (n=8) consuming 200 mg of
vitamin C twice daily for two weeks experienced fewer aches and better
muscle function after prolonged exercise than men in the placebo group
(n=8).4
According to NMI, vitamin C is one of the more popular supplements among
athletes. For example, 50 percent of joggers and 51 percent of bodybuilders
take vitamin C, as compared to 45.4 percent of the general population.
Vitamin C's beneficial effect on muscle soreness may not occur with one-time
supplementation. Thompson and another group of researchers at Loughborough
University in Leicestershire, England, discovered that acute supplementation
of vitamin C did not prove beneficial on exercise-induced muscle soreness
and damage. The habitually active men (n=9) in this study consumed 1,000
mg of vitamin C just before exercise during one test and then consumed
placebo during another. Researchers did not note any beneficial effects
during the treatment period as compared to placebo. They concluded that
this may be because the supplementation occurred at an "inappropriate"
time.5
Antioxidant vitamins may also be useful in helping athletes adjust to
high-altitude performance by reducing the symptoms of acute mountain sickness.
In a placebo-controlled, double blind study, 18 subjects were randomly
assigned to either an antioxidant regimen or placebo. Volunteers taking
the supplement combination--1,000 mg/d of vitamin C, 400 IU/d of vitamin
E and 600 mg/d of alpha lipoic acid--during a 10-day ascent to a Mt. Everest
base camp at approximately 17,000 feet experienced higher oxygen blood
levels and higher caloric absorption compared to the placebo group.6
Vitamin E has also been tested independently for its role in improving
performance recovery by researchers at the College of Veterinary Medicine
at the University of Florida, Gainesville. Eight adult racing greyhounds
were given 680 IU/d of vitamin E (alpha-tocopheryl acetate) for seven
days. Their blood concentrations of alpha-tocopherol were measured before
and after racing prior to the supplementation regimen, as well as seven
days after supplementation began. Results indicated that concentrations
of alpha-tocopherol, a component of vitamin E, were significantly higher
overall during treatment, although levels did not differ before or after
racing. Researchers noted that vitamin E supplementation eliminated the
typical after-racing decrease in alpha-tocopherol that was detected before
supplementation began. They concluded that vitamin E may decrease oxidation
during exercise, making it applicable in the realm of improving performance
or recovery.7
Coenzyme Q10 (CoQ10) is another antioxidant thought to affect athletic
performance. Otherwise known as ubiquinone, CoQ10 is produced in the body
and is responsible for transporting energy from one enzyme to another
during ATP production. As humans age, however, CoQ10 synthesis is affected
and a deficiency can develop.8 A deficiency of CoQ10 can lead to "exercise
intolerance," according to researchers at the Columbia University
College of Physicians and Surgeons in New York.9
Although CoQ10 is responsible, in part, for energy production, there is
a lack of evidence that the nutrient can improve physical performance.
Researchers at the University of Parma in Italy studied 28 healthy male
cyclists who were randomized into two groups--CoQ10 or placebo. Subjects
underwent cardiopulmonary exercise testing at baseline and at the end
of the eight-week study period. At the end of the study period, there
was no difference between the two groups in physiological or metabolic
parameters, although the CoQ10 group reached muscular exhaustion with
higher workloads than the placebo group. Researchers concluded that CoQ10
oral treatment does not improve aerobic power, although it does seem to
slightly improve tolerance to higher workloads, which could be due to
its antioxidant activity.10
Astaxanthin, a naturally occurring carotenoid pigment and powerful antioxidant,
may also have application in the realm of performance nutrition. While
there is some speculation that astaxanthin can reduce muscle soreness
in athletes, research on this topic is scarce. However, an unpublished
human clinical trial conducted at Tennessee's University of Memphis demonstrated
that astaxanthin (as BioAstin®, by Cyanotech Corp.) can reduce knee
soreness after strenuous leg exercises. In addition, the study indicated
that the athletes taking the supplement experienced a significantly stronger
immune system response compared to the control group after exercise.
Aside from antioxidant vitamins, numerous B vitamins play a role in performance
nutrition, as they are responsible for assisting in energy metabolism.
Vitamin B supplements are fairly popular among athletes--25.4 percent
of joggers and 33.3 percent of bodybuilders take B vitamins or a B complex
as compared to 24 percent of the general population, according to NMI.
The body uses vitamin B3 (niacin) to release energy from carbohydrates.
Vitamin B3 comes in two basic forms--niacin (also called nicotinic acid)
and niacinamide (also called nicotinamide). Researchers at the Deakin
University in Burwood, Australia, determined that niacin may improve carbohydrate
metabolism during cycling in women who are unaccustomed to exercise. The
women in the supplement group ingested 7.4 mg/kg body weight 30 minutes
before exercise, 3.7 mg/kg at 0 minutes and 3.7 mg/kg after 30 minutes
of exercise. Glucose kinetics were measured after exercise and researchers
learned that glycerol (a three-carbon alcohol derived from the breakdown
of fats) levels were suppressed throughout exercise. They concluded that
during prolonged moderate exercise, subjects exhibited increased glycogen
utilization, which compensated for carbohydrate oxidation.11
NADH (nicotinamide adenine dinucleotide), sometimes known as coenzyme
1, is the active coenzyme form of vitamin B3 and is necessary for energy
production. NADH is utilized in the body during an oxidation process that
fuels the ignition of ATP. Because it is not manufactured in the body,
NADH must be obtained from dietary sources such as fish, beef and chicken,
as well as foods that are made with yeast.
NADH has been linked to improved mental function and for treating the
symptoms of chronic fatigue syndrome. Currently, some athletes take supplemental
NADH as an ergogenic aid to improve performance. However, there are no
published clinical trials demonstrating the safety or efficacy of this
practice.
Some of the other B vitamins are also involved in energy production, although
research proving their efficacy in performance nutrition is limited. Vitamin
B1 is needed to process carbohydrates, fat and protein, and is required
to produce ATP. Pantothenic acid (vitamin B5) is also involved in Kreb's
Cycle and is essential for producing, transporting and releasing energy
from fats. Vitamin B12 deficiency is known to cause fatigue, and injections
of the nutrient have been used to combat the symptoms of chronic fatigue
syndrome, although the efficacy of this practice is unproven. Vitamins
B6 and B12 are also linked with reducing immunosuppression in athletes.
Minerals
Similar to vitamins, minerals are also heavily involved in energy metabolism.
Specifically, magnesium, zinc and chromium are integral for optimal performance,
according to a research review conducted by Hank C. Lukaski, Ph.D., supervisory
research physiologist at the Grand Forks Human Nutrition Research Center,
an affiliate of the U.S. Department of Agriculture. Lukaski stated in
his review that there is accumulating evidence supporting the hypothesis
that magnesium and zinc are significant for promoting strength. However,
he also stated the supportive evidence for chromium in performance is
not well-established.12
Magnesium is a necessary nutrient for energy metabolism. It activates
the body's store of B vitamins and assists in the formation of protein,
fatty acids and ATP. "Magnesium is vital for energy release,"
wrote Kumar Pati, M.D., and Anthony James Degidio, D.O., M.D., in Vitamin
& Herbal Digest (New Editions Publishing, 1996). "Our muscles
and nerves need magnesium to function properly."
Zinc is also necessary for proper body function and is a component of
more than 300 enzymes that support various body functions, including protein
synthesis. Zinc's immune-boosting properties make it especially popular
with athletes due to exercise-induced immunosuppression. Dietary deficiencies
of protein and specific micronutrients have long been associated with
immune dysfunction, according to a review on the importance of nutrition
in athletes written by researchers at the University of Edgbaston in Birmingham,
England. They suggested that adequate intakes of B vitamins, zinc and
iron are necessary for maintaining immune function in athletes.13
Chromium, an essential trace mineral that helps the body maintain normal
blood sugar levels, may also improve body composition by reducing fat
and increasing lean muscle tissue. A large study conducted by researchers
at the Health and Medical Research Foundation in San Antonio, Texas, determined
that chromium picolinate supplementation can lead to significant improvement
in body composition. Subjects (n=154) were randomly assigned to receive
either 200 mcg/d or 400 mcg/d of chromium picolinate (as Chromax®,
manufactured by Purchase, N.Y.-based Nutrition 21) or placebo for 12 weeks.
At the end of the study period, researchers noted that subjects in both
treatment groups exhibited significant improvements in body composition--reduced
fat and increased lean muscle tissue.14
A smaller, more recent trial comparing chromium picolinate to placebo
failed to duplicate these results. Researchers at California State University
in Fullerton found no significant differences in the muscular strength
or body composition of female softball players who took 500 mcg/d of chromium
picolinate (as Chromax) for six weeks.15
Iron is another mineral that is useful in preventing immunosuppression
and is also necessary for energy production. Iron deficiency can induce
fatigue because it is an essential component of hemoglobin, which is responsible
for transporting oxygen to the cells. Iron-deficient people tire easily
in part because their bodies are starved for oxygen. Also, without enough
iron, ATP cannot be properly synthesized. As a result, some iron-deficient
people become fatigued even when they are not anemic.
Iron deficiency in non-anemics has been known to reduce muscle tissue
oxidative capacity and endurance, although iron supplementation may be
useful for reversing this condition. Two studies have demonstrated this
effect of iron supplementation (50 mg/d). The first study--conducted at
Cornell University in Ithaca, N.Y.--involved 41 iron-depleted, non-anemic
women who were unaccustomed to aerobic activity. Researchers found that
the women's difficulty tolerating aerobic exercise was reversed after
six weeks of iron supplementation.16 A similar trial conducted by the
same researchers included 49 women who supplemented with iron for six
weeks and achieved an improved response to endurance training.17
The Majority of Sports Nutrition Users Say That Vitamins, Minerals and
Herbs Are Effective & Important
Amino Acids
Amino acids are the building blocks of protein, 20 of which exist to build
the various proteins used in the growth, repair and maintenance of body
tissues. Nine of these are essential amino acids that are not produced
in the body and must be obtained from the diet.
Glutamine, the most abundant amino acid in the body, is converted to glucose
when more is required by the body for energy. Reduced plasma glutamine
concentrations have been linked to exercise-induced immune impairment,
according to researchers at The Copenhagen Muscle Research Center in Denmark.18
However, according to a review written by researchers at Deakin University
in Burwood, Australia, there are few controlled trials that support the
supplemental use of glutamine for reducing immunosuppresion.19
An amino acid metabolite, L-carnitine, is created in the body from the
amino acids lysine and methionine. L-carnitine assists the utilization
of fat as energy by transporting fatty acids to the mitochondria, where
ATP is created. Supplemental L-carnitine may improve athletic performance
and aid in muscle recovery. Researchers from the Universidade de Sao Paulo
in Brazil suggested L-carnitine's ability to improve aerobic capacity
may be due to the nutrient's stimulation of lipid oxidation in muscle
cells during long-term exercise.20 And, a study conducted by researchers
from the University of Connecticut in Storrs determined that supplementing
with a combination of 500 mg of L-carnitine and 236 mg of L-tartrate (as
L-Carnipure®, manufactured by Fair Lawn, N.J.-based Lonza Inc.) can
improve recovery from high-repetition muscle training.21
L-theanine, an amino acid derived from green tea, has applications in
immune enhancement, stress management, and physical and mental relaxation.
For these reasons, it may also be applicable to performance nutrition.
One study demonstrated the effects of L-theanine (as Suntheanine®,
manufactured by Taiyo Kagaku in Yokkaichi, Japan, and distributed by NutriScience
Innovations, Fairfield, Conn., and Cyvex Nutrition in Irvine, Calif.)
on alpha-brain waves in humans, which illuminate states of relaxation.
Researchers from Taiyo Kagaku discovered that L-theanine encouraged relaxation
in subjects without inducing drowsiness.22
Soy protein has also been studied in the realm of performance nutrition.
As a protein, soy is a component of amino acids and may be helpful for
improving lean body mass and reducing recovery time. According to a study
conducted by researchers at Ohio State University, soy protein increases
plasma total antioxidants, which can reduce tissue damage that might occur
as a result of exercising. Researchers, who compared 40 mg of soy protein
(as Solae™, manufactured by St. Louis-based DuPont Protein Technologies)
to 40 mg of whey protein in 20 male collegiate athletes, also noted that
the soy group demonstrated larger reductions in creatine kinase and myloperoxidase
levels, which are markers for muscle damage and inflammation, respectively.23
Whey protein is a dairy-based source of amino acids that has been suggested
for athletic performance, specifically in bodybuilding. Whey protein provides
the body with the branched-chain amino acids leucine, isoleucine and valine,
which are needed for muscle maintenance.
Researchers from St. Francis Xavier University in Nova Scotia, Canada,
conducted a study to determine muscular adaptations during six weeks of
resistance training in 36 men who were randomized to receive whey protein,
whey protein combined with creatine, or placebo. The combination group
experienced the best increase in lean muscle mass, although the whey group
also had significant gains as compared to placebo. Men supplemented with
whey protein also experienced greater improvements in lean tissue mass
than men who only trained. And, men in the combination group had greater
increases in lean tissue mass and bench press than those with whey only
or placebo. Continued strength training for an additional six weeks without
supplementation was found to maintain lean muscle mass and strength in
all men.24
Sports Nutrition Users' Top Reasons For First Use of Sports Nutrition
Products: Performance/Energy
Additional Nutrients
Creatine is a popular sports nutrition supplement among both old and young
athletes as an ergogenic aid, as well as for its ability to increase lean
muscle mass and delay muscle fatigue. A survey of 1,349 high school football
players conducted by researchers at the University of Wisconsin Hospital
Sports Medicine Center in Madison indicated that 30 percent of the students
had used creatine, with seniors (50.5 percent) being more likely to use
the supplement than freshmen (10.4 percent).25
The fact that creatine use is popular among teenagers has been of some
concern due to a lack of education and potential side effects. The Blue
Cross and Blue Shield Association distributed an educational advisory
to schools nationwide regarding "potentially dangerous" sports
supplements, including creatine. The Foundation warned that long-term
side effects of sports supplements are unknown and teens should consult
a physician before starting regular supplement use.
The report also mentioned anecdotal evidence linking creatine to kidney
problems. Aside from potential kidney problems, creatine may also cause
leg and stomach cramps, especially if it is not taken with sufficient
amounts of water. One study indicated that creatine supplementation led
to abnormal increases in anterior compartment pressure in the lower leg
at rest and following 20 minutes of level running at 80 percent of maximal
aerobic power.26 However, a retrospective study of creatine use did not
indicate a difference between creatine use and non-use groups with regard
to muscle injury, cramps or other side effects. Researchers concluded
that this data shows long-term creatine supplementation does not lead
to adverse events.27
As for its beneficial effects, creatine has been touted for improving
exercise performance and muscle recovery. A study conducted at the University
of Birmingham in the United Kingdom demonstrated that oral creatine supplementation,
compared to placebo, enhanced exercise performance in nine competitive
squash players who took creatine monohydrate four times daily for five
days.28
Another study conducted by scientists at the University of Saskatchewan
in Saskatoon indicated that creatine supplementation may increase lean
tissue mass in older men. Thirty men involved in a randomized, double
blind study took .3 g/d of creatine for every 1 kg of body weight or placebo
for 12 weeks. Both groups resistance trained three times per week. The
creatine group had significantly higher scores for average power, lean
tissue mass and fat mass. Study authors concluded that supplementation
improved leg strength and endurance.29
Magnesium-creatine chelate may offer enhanced benefits to athletes, according
to an animal study published by Max Motyka, M.S.R., Ph.D., director of
the human products division at Clearfield, Utah-based Albion Advanced
Nutrition.30 Animals supplemented with magnesium-creatine chelate outperformed
animals supplemented with creatine monohydrate, creatine monohydrate plus
magnesium oxide, creatine monohydrate plus magnesium amino acid chelate,
or placebo. Motyka concluded that magnesium-creatine chelate (as Creatine
MagnaPower™, manufactured by Albion) enhanced the animals' ability
to generate and regenerate ATP for muscular performance.
Pyruvate is a product of ATP creation--it is created in the body during
the metabolism of carbohydrates and protein. Research published in 1990
indicated that pyruvate supplementation enhanced exercise endurance, although
more recent research indicates otherwise. Researchers from the University
of Guelph in Ontario, Canada, supplemented nine recreationally active
subjects with 7, 15 and 25 g of pyruvate for seven days. Performance tests
to exhaustion indicated that the subjects taking oral pyruvate did not
achieve enhanced performance during intense exercise.31
Conjugated linoleic acid (CLA), a fatty acid found mainly in milk fat,
may have application in performance nutrition because of its propensity
to reduce body fat and increase lean body mass. An animal study conducted
at the University of Wisconsin in Madison determined that mice supplemented
with CLA (as Tonalin® CLA, manufactured by Vernon Hills, Ill.-based
Natural Inc.) exhibited 57 percent to 60 percent lower body fat and 5
percent to 14 percent increased lean body mass compared to controls.32
These results were duplicated by researchers at Pennsylvania State University
in University Park when they sought to determine CLA's (as Tonalin CLA)
mechanism of action.33
When researchers at the Scandinavian Clinical Research center in Kjeller,
Norway, sought to duplicate these results in humans, they found that subjects
taking 3.4 g/d and 6.8 g/d of CLA experienced a reduction in body fat;
however, researchers did not note a difference in lean body mass between
treatment groups and placebo.34
MSM (methylsulfonyl-methane) is a naturally occurring sulfur compound
said to help maintain the body's protein structure and immune system.
When used as a supplement, MSM is thought to improve injury recovery in
athletes. A double blind, placebo-controlled study of 24 patients selected
from the clinic of Ronald Lawrence, M.D., Ph.D., showed that patients
in the treatment group (taking Lignisul™ MSM, manufactured by Carolwood
Corp. in Greenville, Pa.) had a level of significant recovery (58 percent)
compared to those taking placebo (33.3 percent).
Body Builders Are Three Times More Likely Than GP To Use Sports Nutritional
Products
Botanicals
While numerous nutrients and compounds found in the human body can improve
athletic performance by quickening recovery time and improving strength,
various botanicals can also enhance performance by providing a jolt of
energy and potentially reducing tissue damage.
Cordyceps sinensis, for example, is a traditional Chinese herb that may
enhance endurance and exercise performance, according to researchers who
presented at the annual meeting of the American College of Sports Medicine
(Southwest Chapter) in November 2001. Researchers from the Center for
Clinical and Lifestyle Research in Shrewsbury, Mass., tested 110 healthy,
sedentary adults who were randomized to receive either Cordyceps or placebo
for 12 weeks. Subjects in the treatment group exhibited an increase in
overall maximal oxygen consumption (5.5 percent), an increase in work
output on a bicycle (2.8 percent) and a 20-second reduction in the one-mile
walk. Researchers concluded that Cordyceps (as CordyMax Cs-4, manufactured
by Pharmanex) had a metabolic effect by improving oxygen consumption,
energy metabolism and endurance performance.
Velvet antler (deer velvet) may also have application in the realm of
performance nutrition, according to research published online by Velvet
Antler Research New Zealand (www.velvet.org.nz). One study involving 51
male athletes who were randomized to supplement with New Zealand deer
velvet or placebo demonstrated that velvet antler improved isokinetic
strength and muscular endurance more effectively than placebo. A second
study, which involved 30 athletes, indicated that those athletes taking
New Zealand deer velvet powder for two weeks prior to treadmill exercise
showed reductions of creatine kinase in their bloodstream, a marker for
muscle damage. (These studies were commissioned by Velvet Antler Research
of New Zealand, a joint venture between the New Zealand Game Industry
Board and AgResearch.)
Guarana is another botanical suggested for athletic performance for its
energy-enhancing ability. Guarana is an evergreen vine indigenous to the
Amazon basin that has a similar effect on the human body as caffeine--it
is known to stimulate the nervous system and increase metabolism. Because
of this, the herb has been indicated in cases of over-stimulation.35
"The extract of the guarana plant, grown in Brazil, contains caffeine--many
people's favorite pick-me-up," wrote Pamela Smith, R.D., in The Energy
Edge (LifeLine Press, 1999). "It's chemically the same as an afternoon
espresso. Yes, it's natural, but so are coffee beans. Caffeine is a stimulant
that acts on your central nervous system and can speed up your heart rate."
Unlike guarana, ginseng is not a stimulant; rather, it is an adaptogen
and has positive effects on the immune system. Ginseng is often promoted
for its energy-boosting ability and is favored among athletes, with 21.2
percent of joggers and 19.8 percent of bodybuilders taking it as compared
to 12 percent of the general population, according to NMI.
Ginseng supplements are created from three varieties of the plant: Asian
ginseng (Panax ginseng), American ginseng (Panax quinquefolius) and Siberian
ginseng (Eleutherococcus senticosus). A review of herbs and exercise performance
suggested that Asian ginseng improves exercise performance, including
muscular strength, oxygen uptake, work capacity, heart rate, alertness
and psychomotor skills, in studies of eight weeks or longer.36 The same
review reported that trials utilizing Siberian ginseng are mixed. Researchers
from the University of Southern Mississippi in Hattiesburg conducted a
study with nine highly trained cyclists who took either Siberian ginseng
or placebo for seven days prior to performance tests. Cycling times were
not improved in either group.37
Asian ginseng may prove to be beneficial to athletes by reducing injury
and inflammation, according to researchers from the University of Leon
in Spain.38 However, long-term supplementation with Asian ginseng does
not have an ergogenic effect on recovery from short, high-energy exercise,
according to researchers from Wayne State University, Detroit.39
Joggers Are Four Times More Likely Than GP To Use Ephedra
Controversial Supplements
Probably the sports supplement that has received the majority of the past
year's negative publicity is ephedra, also known as ma huang. However,
this herb is particularly popular among athletes compared to the general
population. According to NMI, joggers and bodybuilders are four times
more likely to use ephedra than the general population.
Ephedra's active ingredients are the ephedrine alkaloids ephedrine and
pseudoephedrine, which can be extracted from the plant or synthetically
made--synthetic ephedrine alkaloids are considered by the Food and Drug
Administration (FDA) to be drugs and are not permitted for use in dietary
supplements.
Ephedra has received negative media coverage because of its suspected
correlation with adverse events--ranging from increased blood pressure
to death--due to its effect on the circulatory and nervous systems. Late
last year, the Public Citizen Health Research Group (www.citizen.org)
asked the federal government to ban the sale and production of ephedrine
alkaloid dietary supplements and send out an immediate advisory concerning
the possible health risks associated with these products. The letter reported
that FDA's adverse event monitoring system showed that ephedrine alkaloid
supplements were associated with more reports of death, myocardial infarction,
cardiac arrhythmia, hypertension, stroke and seizure than all other dietary
supplements combined.
The Ephedra Education Council (www.ephedrafacts.com) stated that the increased
number of adverse events was due to a large increase in ephedra use during
the same time period. Michael McGuffin, president of the American Herbal
Products Association (AHPA), commented on the letter as well. "It's
important that we acknowledge that ephedra is not a benign substance,
and that there needs to be some government regulatory overview on this
substance," he told INSIDER last year. "We agree with Public
Citizen that there needs to be a change in the regulatory approach to
this ingredient."
While FDA regulates the use of synthetic ephedrine alkaloids as drugs,
Canada's government has acted against both natural and synthetic ephedra
products. In January, Health Canada requested a voluntary recall of certain
products containing either ephedra or ephedrine owing to their finding
that the herb can pose a serious health risk. The products affected by
the Canadian recall included those that have recommended doses exceeding
8 mg per serving or 32 mg/d, as well as combination products containing
other stimulants promoted for weight loss, bodybuilding or energy.
Aside from the political battles being waged on account of ephedra, the
scientific community has also brought arguments against the herb. Researchers
from the New England Medical Center reviewed 37 adverse event reports
involving ephedra use--in which 36 cited using the recommended dosage--and
concluded that the herb is temporally related to stroke, myocardial infarction
and sudden death.40
John Hathcock, Ph.D., vice president of nutritional and regulatory science
for the Council for Responsible Nutrition (CRN), commented that observational
studies tend to be flawed based on self-reporting and missing data--such
as other medications or supplements the patients were taking, and how
much of the herb they were taking. "Ephedra is safe and effective
when used as directed according to the label and by those for whom the
product is intended," he told INSIDER in January. "And that
has to be limited by the label instructions about contraindicated substances
and pre-existing health conditions that would preclude [ephedra use]."
In terms of ephedra's positive effects, the herb may improve athletic
performance, according to a study conducted by researchers from the Defense
and Civil Institute of Environmental Medicine in Toronto. Twelve runners
randomly received either 4 mg/kg of body weight of caffeine, 0.8 mg/kg
of ephedrine or a combination of caffeine and ephedrine. Products were
given 1.5 hours before volunteers ran 10 km on a treadmill while carrying
an 11-kg backpack. The ephedra groups exhibited statistically better run
times--45.5 min. for ephedrine users, 45.7 minutes for caffeine/ephedrine
users--than the caffeine-only (46.0 min.) or placebo (46.8 min.) groups.41
Androstenedione (andro), and related substances androstenediol and norandrostenedione,
is another ingredient that has received negative media attention. The
controversy surrounding andro arguably began when teens strove to mimic
baseball's Mark McGwire to improve their athletic performance by taking
the androgen hormone. Andro is produced in the adrenal glands and gonads
and is converted to testosterone in muscle and bone.
As an anabolic steroid, andro has been banned by the Olympic Committee,
the National Football League and the National Collegiate Athletic Association.
And, its classification as a hormone led California's attorney general,
Bill Lockyer, to file suit on Aug. 15, 2001, against almost three dozen
manufacturers and distributors of andro supplements for violating the
state's Proposition 65, the Safe Drinking Water and Toxic Enforcement
Act of 1986. Lockyer cited the potential for the supplement to "produce
serious reproductive health problems" if taken in doses of 200 to
300 mg.
The doses singled out by Lockyer as being potentially dangerous are typically
recommended doses for enhancing body composition and muscular strength.
However, researchers from East Tennessee State University who conducted
The Andro Project--a trial involving 50 men conducted to discover the
physiological and hormonal effects of 200 mg/d of oral androstenediol
and androstenedione--determined that while the supplement can increase
testosterone levels, it does not necessarily enhance performance.42
Dehydroepiandrosterone (DHEA), an adrenal-derived steroid, has also been
banned by the Olympic Committee and several other sports organizations.
DHEA is believed to build muscle mass, reduce fat and decrease recovery
time following injury; however, clinical research demonstrating these
claims is limited. Researchers from LGE Performance Systems in Orlando,
Fla., determined through a 12-week, randomized, placebo-controlled, double
blind trial with 40 healthy male subjects that DHEA does not independently
elicit a statistically significant increase in lean body mass, strength
or testosterone levels.43 The same results were found by researchers at
Iowa State University in Ames44 and from a review done by researchers
at the University of Massachusetts in Amherst.45
HMB (beta hydroxy-beta-methylbutyrate) is a metabolite of the essential
amino acid leucine, a branched-chain amino acid. HMB is purported to assist
in protein synthesis, acting as an anticatabolic agent and minimizing
protein breakdown and cell damage that occurs during intense exercise.
Researchers at the Academy of Physical Education in Warsaw, Poland, discovered
that HMB supplementation acted in a similar fashion to creatine. During
three weeks of progressive resistance-exercise training, 40 subjects were
randomized to receive one of four treatments: creatine, HMB, creatine
plus HMB, or placebo. All three treatment groups gained lean body mass,
with the combination group gaining the most, creatine second and HMB third.
In addition, all treatment groups improved in strength--the combination
group, again, improved the most, with the HMB group exhibiting the second
most improvement. Researchers concluded that creatine and HMB can increase
lean body mass and strength, with better effects being evident with combination
therapy.46
Another study was conducted by researchers at South Dakota State University
to determine whether the increases in strength and fat-free mass during
weight training with HMB supplementation seen in young men could be applied
to elderly men as well. For this purpose, 31 men and women, aged 70 and
older, were randomized to receive HMB (3 g/d) or placebo for eight weeks
during a progressive resistance training program. Results indicated both
an increase in lean body mass and strength with daily HMB supplementation.47
However, additional research has not shown these beneficial effects. Researchers
at the University of Queensland in Brisbane, Australia, found that short-term
HMB supplementation (40 mg/d per kg of bodyweight) did not demonstrate
a beneficial effect on symptoms associated with muscle damage. Researchers
concluded that if HMB can produce an ergogenic response, a pre-exercise
supplementation longer than six days may be necessary.48
The countless dietary supplements available that are targeted toward athletes
may seem slightly daunting. However, these products are all targeted to
different aspects of performance nutrition: developing lean body mass,
enhancing performance, combating immunosuppression, etc. With these topics
in mind, manufacturers can choose which ingredients best fit their formulations,
and consumers will be able to create a specialized regimen for their particular
needs.