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Athletes ask me about supplements. They want to get bigger, faster and stronger—or
they want help losing weight without hunger or will-power. The loaded shelves of your
local health food store groan with supplements. And every day new miracle substances are
created.
So how do you make sense of all the contradictory claims? Let’s examine several
common supplements: those that are definitely worth it, others that might be useful under
certain circumstances, some that are a waste of money, and supplements that might be
harmful.
Definitely Worth It
Aspartates (Potassium and magnesium). Aspartates (salts of aspartic acid) are nonessential
amino acids occurring naturally in protein. They are available in supplement form as
Potassium Aspartate or Magnesium Aspartate and are normally taken in doses of 7 to 12
grams in 24 hours.
Several studies show that aspartates enhance aerobic performance as much as 37 percent,
though it’s unclear whether the subjects were in a deficient state before the studies
began. One theory maintains that ammonia in the blood may cause fatigue, and aspartates
reduce the accumulation of ammonia during aerobic exercise.
No adverse side effects have been reported in doses of 10 grams in 24 hours, although
larger doses may cause diarrhea. Aspartates are legal.
Sodium Bicarbonate. Most people are surprised to learn that common baking soda might
enhance performance. According to the theory, sodium bicarbonate is alkaline so it can
neutralize the lactic acid that forms during intense exercise, thus delaying the onset of
fatigue. The usual dose for a 154-pound male is 5 to 6 level teaspoons mixed in a quart of
water, taken one hour before exercise. In the studies, sodium bicarbonate was most
effective in all-out efforts lasting 30 seconds to two minutes, so it would work best for
runners at 400 and 800 meters or track cyclists in the kilometer time trial. A
comprehensive survey of the literature revealed a 27 percent improvement in
time-to-exhaustion in laboratory tests.
Sodium bicarbonate is safe when taken in recommended doses, but can cause gastro-intestinal
distress. It is currently legal for athletes.
Possibly Useful
Phosphate Salts. Phosphorus is an essential mineral that may have performance-boosting
qualities. Its most common form as a supplement is sodium phosphate, taken in daily 4 gram
doses over 4 to 6 days. This supplement is thought to enhance aerobic power by buffering
the lactic acid produced during exercise.
Although results are mixed as to its effectiveness, several studies showed that sodium
phosphate supplementation may increase performance on a stationary bike. It also improved
subjects’ performance in a 40K bicycle time trial.
Phosphate salt supplementation appears safe at the 4-gram per day level. Its use is
currently legal.
Protein Supplements are a convenient way to add protein to the diet, although it’s
better if daily protein intake comes from food sources like lean meat. Protein is thought
to increase muscle mass, reduce recovery time and enhance strength and power.
Studies show that dietary protein needs are increased during intense strength training, so
strength athletes may need 1.4 to 1.8 grams of protein per kilogram of body weight.
Endurance athletes’ protein needs aren’t as great: 1.2 to 1.4 grams per kilogram
of body weight is recommended. How much is that? A 154-pound strength athlete needs 98 to
126 grams of protein daily while a 154-pound endurance athlete needs slightly less: 84 to
98 grams. (For comparison, a glass of protein supplement contains about 45 grams, 6 ounces
of beef contains 52 grams and 4 ounces of cheese packs 32 grams.)
Waste of Time and Money
Boron is a non-essential mineral found in many plant foods like dried fruits, nuts,
applesauce and grape juice. This mineral is thought to increase muscle mass and decrease
body fat but no studies have shown that it is effective. In doses over 50 milligrams per
day, it may be toxic and can cause digestive disturbances.
Tryptophan is an essential amino acid and a natural constituent of protein. Essential for
the formation of serotonin, a brain neurotransmitter thought to decrease perception of
pain, tryptophan is often claimed to improve physical power by increasing the athlete’s
resistance to pain. However, many studies have shown no improvement in performance. In
fact, most studies showed that performance was impaired after tryptophan
supplementation.
Some subjects experienced gastro-intestinal distress and skin itching. In 1989–90,
tryptophan was associated with the development of a serious neuromuscular disorder
resulting in 20 deaths. Tryptophan is legal but may carry potential health risks.
Potentially Harmful
Androstendione (Andro) is a sex hormone produced in the adrenal glands and testis in men
and coverted to testosterone or estrogen. It achieved sudden popularity in the summer of
1998, when baseball player Mark McGwire, in the midst of breaking the home run record,
revealed that he used it. East German athletes apparently took andro intranasally (inhaled
through the nose) to increase testosterone levels for 3 to 5 hours and increase
aggressiveness.
Andro has serious side effects. It can produce masculine features in women and can
feminize men. It’s also associated with increased risk of heart attacks, cancers,
adrenal tumors and liver problems, in addition to a wide array of mood and mental function
disorders. What’s worse, many side effects don’t show up for months or years after
its use. Andro is banned by the International Olympic Committee, the National Football
League, and the NCAA.
Erythropoeitin (EPO) is a hormone that stimulates the production of the red blood cells
that carry oxygen to the working muscles, thus raising the hematocrit or percentage of red
cells in the blood. Hematocrit is usually lower in trained endurance athletes because
training increases the blood volume, diluting the percent of red blood cells. However,
more red blood cells confer an endurance sport advantage because they can carry more
oxygen. The downside? Blood becomes thicker and harder to pump, putting a strain on the
heart.
EPO use has been epidemic in endurance sports like cycling and cross country skiing
because studies show that it increases hematocrit 45 to 50 percent, VO2 max 8 percent and
time-to-exhaustion 17 percent. However, its use is associated with dangerously increased
blood pressure during exhaustive exercise, greater chance of blood clots and in some
cases, death. EPO is especially dangerous because no test currently exists to detect its
presence in the body directly. EPO is banned by sports governing bodies. Obviously, its
use is not recommended.
Some Odds and Ends
Other supplements might be useful in your quest for strength, performance, and health.
Additional products deemed effective by scientific studies include caffeine, creatine, and
carbohydrate to supply glycogen to the working muscles.
Often sold over the counter, supplements of doubtful value include conjugated linoleic
acid or CLA. Several are downright dangerous, such as bee pollen and DHEA. Allergic
reactions to bee pollen include headaches, nausea, and anaphylaxis, a life-threatening
medical condition. Abnormal reactions to DHEA have included increased facial hair and
decreased levels of HDL cholesterol in women. Long-term side effects of DHEA use might
include liver toxicity and prostate cancer in males, although the supplement hasn’t
been around long enough to conduct the appropriate longitudinal studies.
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