From UC Berkeley Wellness Letter, December 2000.
| Athletes looking for even the slightest edge often turn to a wide variety of supplements - called ergogenic aids- that are supposed to boost performance. Many weekend exercisers, seeking to make their workouts easier and/or more productive and to recover from them faster, also try such supplements. We're not talking about anabolic steroids, which do enhance strength and performance, but are banned in most sports as well as being dangerous. Rather, these are ordinary "dietary supplements," with two exceptions: caffeine and baking soda. Just how "ordinary" are they? Are they safe? Effective? Here's an update. | Words to the wise: If you want to build muscle, lose fat, or run, swim, or cycle faster, you're better off with a solid training program than with these supplements. In any case, the small effect these supplements may have would be meaningless for recreational athletes or exercisers, though the risks are just as real. |
| COMPOUND/ SUPPLEMENT |
CLAIMS MADE |
WHAT STUDIES SHOW | COMMENT |
|
Caffeine
|
Improves endurance by helping the body break down fat, thus sparing carbohydrates for later use
|
Several
small studies show that 2 or 3 cups of brewed coffee, drunk within a few
hours of endurance exercise, allows athletes to exercise longer. Other
studies have found little or no benefit.
|
It's not proven that caffeine helps break down fat. People respond differently to caffeine. For some, it boosts alertness and reduces perceived effort. In others, especially those not used to it, caffeine may cause jitteriness that hurts performance. High doses of caffeine cars sometimes boost heart rata and blood pressure excessively. Caffeine is a diuretic and thin increases urination, so increase your intake of non-caffeinated fluids. |
|
Antioxidants (such as Vitamins E and C)
|
Vigorous
exercise boasts cell- damaging free radicals in the body, which may cause
muscle soreness and inflammation after a workout. Antioxidants limit the
damage done by free radicals.
|
Some preliminary studies have found that exercisers who take large
doses of antioxidants, notably vitamins C and E, protect
themselves against some damage by free radicals.
|
There's no clinical evidence that antioxidant supplements prevent muscle
soreness or enhance athletic performance. Wellness
Letter recommends 2,50 to 500 milligrams of vitamin C and
200 to 800 TtJ of vitamin E for everyone (along with at least
five fruits and vegetables a day). Some exercise experts
recommend much higher doses; We think that's unnecessary.
|
|
Amino
Acids
|
Boost muscle growth.
|
There's little or no evidence that protein supplements and/or isolated
amino acids offer any advantage over protein in food.
|
These supplements may create an imbalance in amino acids in the body, and often contain questionable ingredients. Protein is not a concern for even the most active people, since the average American diet supplies more than enough protein. Excess protein is simply broken down in the body and burned for energy or turned into fat. |
|
Creatine (found in meat, poultry, and fish; also made by the body from
two amino acids)
|
Helps restore adenosine triphosphate, or ATP, which supplies quick
energy. Also helps reduce the lactic acid that accumulates in muscles
daring intense exercise and produces a burning sensation.
|
Some small studies have found that supplements can slightly boost short-term muscle strength and the body's ability to perform activities (anaerobic) involving short, rapid bursts of energy, such as sprinting and jumping. But other studies have found no benefit, or even impaired performance. | Long-term health effects of high doses of creative are unknown; the supplements may depress the body's own synthesis of the, substance. If creative does what it is supposed to do, and that's a big if, it would be useful to only a small group of athletes. These supplements certainly aren't for recreational and/or endurance athletes. Even competitive athletes should think twice before trying them. |
|
Androstene dione (hormone
precursor)
|
Boosts
testosterone levels in the blood and builds muscle.
|
One
goad 1999 study found that andro does not do what's claimed, but does
raise levels of estrogen, which is dangerous for men.
|
Don't
take "andro." It supposedly helped Mark McGwire hit a record 70
home runs in 1998. But no one knows whether andro really works; there has
been virtually no research into its safety. It can increase risk of
certain cancers, male breast enlargement, heart disease, and other health
problems.
|
|
Chromium picolinate
|
A safe alternative to anabolic steroids
|
A
few studies have been done on chromium and muscle mass, but the results
have been inconsistent.
|
Several lab studies have raised concerns that chromium picolinate may cause chromosomal damage and have other adverse effects (see Wellness Letter, June 1999). Often accompanied by undesired weight gain. |
|
Carnitine (Found in meat and dairy, made in body)
|
Plays a role in metabolism of fat, important for aerobic exercise.
|
Studies have had mixed results, with most finding no benefit.
|
The is definitely not enough evidence to suggest athletes should take carnitine. In addition, only supplements containing L-carnitine seem to be safe: D-carnitine can actually create a carnitine deficiency causing muscle weakness. |
|
Sodium bicarbonate (baking soda)
|
May potentially neutralize the lactic acid that builds up during strenuous
exertion and causes muscle fatigue.
|
Highly trained athletes may benefit from consuming baking soda before a
short-distance race. But any improvement is minimal: 2 to 3 seconds in
races lasting several minutes.
|
Potentially useful in events lasting one to seven minutes; probably won't help in shorter sprints or longer events. The small benefit may be significant for competitive athletes, but not for most people. Potential drawbacks include severe diarrhea, abdominal cramps, bloating, and nausea. |