IS CREATINE THE ONE
TRUE ERGOGENIC AID?
by Owen Anderson, Ph.D.
copyright © 1994
Bee pollen flopped. So did ginseng, pangamic acid, royal jelly, high-power
vitamin and mineral supplements, and a bewildering array of other products
sold to athletes as "ergogenic aids." All were supposed to convert
even the most laggardly runners into good imitations of Sebastian Coe, but
the cold light of scientific research suggested that the products' users
were usually chumps - not champions.
However, a new ergogenic aid - creatine - may really be capable of improving
performance. The chemical may have powered several British athletes to
gold medals at the Barcelona Olympics in 1992, and new scientific research
indicates that creatine might benefit both sprinters and endurance runners.
One of the reasons for creatine's emergence as a potent performance-booster
is that a venerable Swedish scientist named Eric Hultman is still laboring
away in his laboratory. Back in the 1960s, Hultman and his colleagues at
the renowned Karolinska Institute in Stockholm, Sweden discovered that a
runner's ability to perform prolonged, intense exercise was directly related
to the amount of carbohydrate (glycogen) which was stockpiled in the leg
muscles. This discovery quickly led to the powerful strategy of "carbo-loading,"
in which muscle glycogen was first depleted and then maximized just prior
to an important endurance competition. Today, Hultman, the "father
of carbo-loading," is convinced that creatine supplementation can
also have a dramatic impact on athletic performance.
What Is Creatine, and
What Does It Do?
Creatine itself is not a rare compound extracted in small quantities from
lingonberries or created de novo in sophisticated chemical laboratories.
In the human body, creatine is manufactured routinely by the liver and
kidneys and is present in decent quantities inside muscle, nerve, and sperm
cells. In the muscles, creatine is used to form creatine phosphate (CP),
a high-octane chemical which can supply the energy needed for muscle contractions.
Creatine phosphate provides this energy indirectly. All work done in human
cells - including the work done by muscle cells as they contract - is actually
fueled by the breakdown of adenosine triphosphate (ATP) to adenosine diphosphate
(ADP). ATP itself is normally created inside cells by metabolizing carbohydrate,
fat, or protein in the presence of oxygen.
This usual method of producing ATP works pretty well, except for two key
problems: (1) ATP is generated at a fairly slow rate - too slow to supply
all the energy required during a 200-meter sprint, for example. (2) In
addition, it takes awhile for the ATP-generation process to get started.
As you make the transition from standing still at the starting line of
a race to running at race pace, for example, the conventional method of
ATP production doesn't begin working at full capacity until a couple of
minutes have passed. You need another source of energy to get you through
the opening moments of your races and workouts.
Fortunately, CP is a great alternative source of energy. CP simply donates
its phosphate to ADP, instantly creating the ATP needed to make your muscles
work. If you begin running at close to top speed from a standing start,
creatine phosphate supplies almost all the necessary energy during the first
six seconds of your run. As a result, 100-meter runners must have topnotch
concentrations of creatine phosphate inside their muscles if they want to
perform well. CP is important in longer sprints, too; the chemical furnishes
much of the energy required during 400-meter competitions, for example.
Buffers and Shuttles
In addition to supplying energy, CP also acts as a "buffer" which
helps control spikes in muscle acidity during intense exercise. That's
because as CP helps to create the much-needed ATP, it consumes hydrogen
ions released by the lactic acid which can build up in muscle cells during
intense efforts. Since excess hydrogen ions interfere with muscle contractions,
this "buffering" action helps to delay fatigue.
The traditional view is that lofty CP levels are beneficial primarily for
sprinters, but there's evidence that high CP concentrations might help 5K
and 10K runners, too. For one thing, CP could buffer the sharp rises in
muscle acidity which can occur during within-race surges and also during
the final kick to the finish line. In addition, CP is involved in something
called the "energy shuttle," in which the chemical carries energy
from mitochondria to other parts of muscle cells. Mitochondria are tiny
structures inside muscle cells in which carbohydrate and fat are broken
down to provide energy. The energy can't be used inside the mitochondria,
however; it must be transported out of the mitochondria to your muscles'
contractile proteins, which then use the energy to propel you forward as
you run. CP is your muscle cells' "designated carrier" of this
critical energy. Since the energy transport occurs at a fairly high rate
during 5K and 10K racing, augmented muscle-creatine levels might lead to
new PRs.
The bottom line is that your performance potential rises dramatically as
your muscle-creatine levels increase. The heightened creatine expands muscle
CP, and the CP then boosts sprinting speed, buffers troublesome rises in
muscle acidity, and galvanizes your energy shuttle.
So How Do You Increase
Muscle Creatine?
Hultman's research indicates that there is an easy way to markedly boost
muscle-creatine concentrations: Simply eat the chemical!! In a recent investigation,
Hultman and scientists from England and Estonia asked five middle-distance
runners at Tartu University in Estonia to supplement their diets with 30
grams of creatine monohydrate per day for six consecutive days. Each day,
the creatine was parceled out in six separate doses of five grams each.
During the six-day period, five other Estonian runners of comparable ability
consumed a glucose placebo instead of creatine. The runners were unaware
of the actual compositions of their supplements.
Prior to and following the six days of supplementation, the athletes ran
four 300-meter and (on a separate day) four 1000-meter intervals, with three
minutes of rest between the 300-meter intervals and four minutes of recovery
between the 1000-meter repetitions. Creatine added real fire to the runners'
efforts. Compared to the placebo group, improvement in the final 300-meter
interval (from pre- to post-supplementation) was more than twice as great
for creatine users, and improvement was more than three times as great for
creatine supplementers in the final 1000-meter interval. Total time required
to run all four 1000-meter intervals improved from 770 to 757 seconds after
creatine supplementation, a statistically significant advance. Meanwhile,
the placebo group actually slowed from 774 to 775 seconds. In other words,
after creatine supplementation the performance gap between the two groups
had ballooned from 4 to 18 seconds!
Of special interest is the fact that creatine supplementation was extremely
important during the last interval of each workout: Creatine supplementers
doubled their advantage during the final 300-meter interval and tripled
their superiority in the closing 1000-meter effort. This fits with Hultman's
hypothesis that creatine is likely to be most helpful when lactic-acid levels
are highest and fatigue is greatest.
How High Can You Go?
A separate study lends credence to the link between creatine supplements
and fast running. In work carried out at the Karolinska Institute, Hultman
and two other scientists supplemented the diets of 17 individuals with 20-30
daily grams of creatine monohydrate for two or more days. The supplementation
dramatically boosted quadriceps-muscle concentrations of creatine, sometimes
by as much as 50-60 percent.
To determine whether exercise could augment the amount of creatine hoarded
by muscles, some of the Karolinska participants followed a unique training
program during supplementation: They pedaled a bicycle ergometer for one
hour each day while using only one leg to supply the pedaling force. With
supplementation, the unexercised legs increased their creatine contents
by about 25 percent, but the exercised legs advanced their creatine concentrations
by a full 37 percent. Exercise, by increasing blood flow to the muscles
or by changing the rate at which muscles grabbed creatine from the blood,
bolstered the creatine-loading effect.
To boost your muscles' concentrations of creatine, would you have to take
creatine capsules, as did the subjects in the Hultman studies? The primary
dietary sources of creatine are beef and fish, especially raw beef and
fish (Heating tends to destroy creatine). However, moderate upswings in
meat consumption are unlikely to lead to lofty levels of muscle creatine.
For example, to take in 30 daily grams of creatine (the amount ingested
by participants in the Karolinska research), you would have to wolf down
almost 15 pounds of steak per day. True, the Karolinska subjects eventually
began urinating out about 68 percent of their ingested creatine, so perhaps
only 10 grams were actually required to boost muscle-creatine levels, but
that still would amount to 5 pounds of daily beefsteak!
Would Vegetarians
Benefit Most?
True-blue vegetarians take in no dietary creatine at all, but that doesn't
mean their muscles are totally lacking in CP: In humans, the liver, pancreas,
and kidneys can usually manufacture creatine from glycine and arginine,
two important amino acids found in a variety of foods. However, vegetarians
tend to have lower plasma and urinary levels of creatine than do meat-eaters,
and the two vegetarians in the Karolinska study seemed to benefit much more
from creatine supplementation than did the carnivorous Karolinska subjects.
In fact, one vegetarian augmented muscle-creatine content by a whopping
60 percent in his exercised leg, far above the average figure of 37 percent.
The bottom line is that both vegetarians and moderate meat-eaters probably
have enough muscle creatine to sustain routine activity, but it's unlikely
that their muscles have the super-high concentrations which are linked with
heightened athletic performances. Athletes with low creatine levels, including
vegetarians and individuals who eat small quantities of meat, are probably
the ones who will benefit most from creatine supplementation.
Who Has Used Creatine?
Should It Be Banned?
Although the published research on creatine is recent, the chemical is
no stranger to international athletic competitions. Topnotch Russian and
Bulgarian athletes probably utilized creatine at past Olympic games, and
several medal-winning British Olympians ingested creatine during their recent
Barcelona Olympic preparations. An August 7, 1992 article in the London
Times reported that Linford Christie, the gold medal winner at 100 meters,
had utilized creatine prior to the Olympics, and an article in Bodybuilding
Monthly named Sally Gunnell, gold medalist in the 400-meter hurdles, as
another creatine user. Several medal-winning British rowers also gobbled
down creatine during their preparations for Barcelona.
Colin Jackson, the high-flying British 110-meter hurdler who was also identified
by the Times as a creatine sampler, did not capture an Olympic medal but
subsequently beat the Olympic gold medalist - Mark McCoy - on several occasions.
Jackson was quoted by Bodybuilding Monthly as saying, "The results
I had (with creatine) during training and competition were excellent."
Since creatine appears to provide performance advantages to its users,
some critics have suggested that creatine supplementation should be banned
prior to important competitions. However, the International Amateur Athletic
Federation (IAAF) does not list creatine as a prohibited substance, and
Dr. Roger Harris, one of the scientists who worked with Hultman, believes
that banishment would be preposterous. "If creatine is banned, then
we'll also have to abolish the eating of raw meat, rare steaks, sushi, uncooked
oysters, and raw eggs," argues Harris. "After all, individuals
who eat a lot of raw meat have been known to take in up to 15 grams of creatine
per day, and ingesting just nine grams per day for seven days may be enough
to improve performance.". In Harris's view, creatine consumption is
no more sinister than carbo-loading. If creatine were prohibited, then
carbo-loading would also have to go, and perhaps one day all Olympic athletes
would be forced to spend the last 30 days prior to the Games ingesting completely
uniform, standard diets (perhaps consisting only of Mars Bars® and Coca-Cola®,
in deference to recent Olympics' sponsors).
However, Dr. Ron Maughan, a distinguished exercise physiologist at the
University of Aberdeen in Scotland, points out that the International Olympic
Committe does currently prohibit the use of normal dietary components when
they are ingested in abnormal amounts. Caffeine certainly falls into this
category and is banned (above a certain quantity) by the IOC, so creatine
supplementation may eventually be outlawed, too. However, such a prohibition
would be hard to enforce and might end up punishing individuals with naturally
high levels of muscle creatine.
The Practical Side of Creatine
Creatine is not currently banned by any governing body, and it's clear
that creatine supplements can boost muscle concentrations of creatine phosphate,
especially in muscles which are being exercised. From the Hultman-Harris
research and the experiences of the British Olympians, it's likely that
these elevated CP levels can improve training and upgrade race performances.
A "maintenance dose" of creatine would probably amount to three
grams per day, while a pre-competitive intake could consist of 20 grams
of creatine each day during the four days leading up to an important competition.
If creatine helps runners, it should also accelerate the performances of
cyclists, swimmers, climbers, rowers, skiers, and other endurance athletes.
Participants in intermittent-effort, high-intensity sports like soccer,
football, basketball, ice hockey, tennis, squash, etc., in which CP is called
upon to provide sudden bursts of energy, should also benefit.
Since CP must first "donate" its energy to ATP before a muscle
cell can actually contract, some individuals have suggested that athletes
should use ATP - not creatine - supplements. This appears to be a bad idea:
For one thing, creatine can easily pass from the bloodstream into a muscle
cell by squeezing through the muscle membrane, but ATP can't. For this
reason, even intravenous administrations of ATP probably wouldn't work.
Also, muscle cells tend to keep a tight lid on their concentrations of
ATP, while CP levels can rise dramatically after appropriate supplementation.
Summing Up
Here are some final points about creatine:
(1) Creatine supplements appear to provide an athletic edge. Even Dr.
Maughan, not a big fan of creatine, admits that "there's now little
doubt that creatine can improve performance."
(2) Two key factors control how much creatine is present in your muscles
- the quantity of creatine in your diet and the amount of creatine synthesized
by your liver and kidneys. Provided you're currently eating a protein-adequate
diet, there's nothing you can do about your internal organs' rate of creatine
creation. The only effective way to boost your muscle creatine is to eat
more raw meat or take creatine supplements.
(3) If you're interested in creatine, don't blithely begin dosing yourself
with the chemical. Although there are no known side effects associated
with creatine intakes of 1-10 grams per day (Such intakes are within the
normal dietary range), it's always wise to get your physician's OK first.
(4) A routine, maintenance intake of creatine is probably about three grams
per day. A "creatine-loading" amount, taken during the four days
leading up to a major competition, would be around 20 grams per day. Don't
fool around with quantities greater than this.
Evolutionary biologists believe that creatine phosphate is an "ancient"
chemical similar to the one which provided the energy for the first coordinated
movements by life forms on earth - the swimming of sperm cells toward eggs.
The waggling, propulsive motions of sperm tails are still ultimately powered
by creatine phosphate, as are muscle contractions. However, there's nothing
primeval about creatine's role in modern athletics. It appears that creatine
is an ergogenic aid which really works. ©
--------------------------------------------------------------------------------------------------------------------------------------------
YES! I WANT A FREE SAMPLE COPY OF RUNNING RESEARCH NEWS - OWEN ANDERSON'S
NEWSLETTER ABOUT ENDURANCE TRAINING AND SPORTS NUTRITION.
NAME __________________________________________________
ADDRESS ____________________________________________________
CITY, STATE, ZIP ___________________________________________________
Please mail this form to Running Research News, P O Box 27041,
Lansing, MI 48909 or
call 517-393-3150