Whether you’re an accomplished athlete or you’ve just started an exercise
program, you need to know about creatine. Many supplements touted over the
years as performance enhancers have come and gone, but creatine is here to
stay. We predict that it will be one of the most popular muscle-building
nutrients ever made available to you. Why? Because it works. Yes, it really
works.
What is Creatine?
When we told our friends that we were writing a book on creatine, some of
them had quizzical responses. “You’re writing on creating? Creating what?”
“Is it an herb?”
Creatine is a nutrient that is naturally found in our bodies. It is made
from a combination of the three amino acids arginine, glycine and
methionine. Creatine helps provide the energy our muscles need to move,
particularly movements which are quick and explosive in nature. This
includes the types of motion involved in most sports. Approximately 95
percent of the body’s creatine supply is found in the skeletal muscles. The
remaining five percent is scattered throughout the rest of the body, with
the highest concentrations in the heart, brain and testes. (Sperm is
chock-full of creatine!)
The human body gets most of the creatine it needs from food or dietary
supplements. Creatine is easily absorbed from the intestinal tract into the
bloodstream. When dietary consumption is inadequate to meet the body’s
needs, a limited supply can be synthesized from the amino acids arginine,
glycine and methionine. This creatine production occurs in the liver,
pancreas and kidneys.
How Does Creatine Work?
Creatine is an essential player in one of the three primary energy systems
used for muscle contraction. It exists in two different forms within the
muscle fiber: as free (chemically-unbound) creatine and as creatine
phosphate. This latter form of creatine makes up two-thirds of the total
creatine supply. When your muscles contract, the initial fuel for this
movement is a compound called ATP (adenosine triphosphate). ATP provides
its energy by releasing one of its phosphate molecules. It then becomes a
different compound called ADP (adenosine diphosphate). Unfortunately, there
is only enough ATP to provide energy for about ten seconds, so for this
energy system to continue, more ATP must be produced. Creatine phosphate
comes to the rescue by giving up its phosphate molecule to ADP, recreating
ATP. This ATP can then be “burned” again as fuel for more muscle
contraction. (We’ll discuss all this in greater detail in Chapter Six.)
The bottom line is that your ability to regenerate ATP depends on your
supply of creatine. The more creatine you have in your muscles, the more
ATP you can remake. This allows you to train your muscles to their maximum
potential. It’s that simple. This greater ATP resynthesis also keeps your
body from relying on another energy system called glycolysis, which has
lactic acid as a byproduct. This lactic acid creates the burning sensation
you feel during intense exercise. If the amount of acid becomes too great,
muscle movement stops. But if you keep on regenerating ATP because of all
the creatine you have, you can minimize the amount of lactic acid produced
and actually exercise longer and harder. This helps you gain strength,
power and muscle size; and you won’t get fatigued as easily.
Creatine has also been shown to enhance your body’s ability to make
proteins within the muscle fibers. Two of these proteins, actin and myosin,
are essential to all muscle contraction. So when you build up your supply
of these contractile proteins, you actually increase your muscle’s ability
to perform physical work. And the more work you do (whether it’s lifting
weights or running 100-meter dashes), the stronger you become over time.
Athletes frequently divide their creatine use into two phases. The first
phase, called the loading phase, fills up the muscle fiber’s storage
capacity for this nutrient. This phase usually lasts five to seven days.
After that, athletes reduce their creatine consumption to a lower dosage
level which continues for an extended period of time. This second phase is
called the maintenance phase.
How Much Creatine Is In My Body?
The amount of creatine you have in your body depends mostly on the amount
of muscle you have. (There is no creatine in body fat.) The average 70 kg
(155 lb) person has a total of about 120 grams (4.2 ounces) of creatine in
their body at any one time. Vegetarians by and large have lower creatine
levels than meat-eaters. A study by Walker showed that the average
sedentary person uses up about two grams of creatine per day. This creatine
is broken down into a waste product called creatinine, which is collected
by the kidneys and excreted in the urine. Athletes use up much more than
two grams per day, with the exact amount depending on the type of sport,
intensity level and muscle mass.
Can I Get Enough Creatine From My Diet?
The average person consumes about one gram of creatine per day. Creatine is
found in moderate amounts in most meats and fish, which are, after all,
skeletal muscle. Good sources of dietary creatine include tuna, cod,
salmon, herring, beef and pork. Tiny amounts are found in milk and even
cranberries. While it would seem logical that chicken and turkey have
creatine as well, we were unable to find any published data to confirm
this. Cooking destroys part of the creatine that exists in these foods.
An important thing to remember is that meats and fish contain a lot more
than creatine. All animal flesh contains relatively high amounts of
cholesterol. Most meats, especially beef and pork, also contain high
quantities of fat. One kilogram (2.2 pounds) of raw round steak contains
only four grams of creatine, but 119 grams of fat. Porterhouse steak has a
bit less creatine, but 325 grams of fat per kilo! Needless to say, you
won’t live to your 90s if you clog your arteries with the fat and
cholesterol from all of the meat or even fish you’d have to eat to get the
creatine you need to improve your strength and power. What you need is a
nonfat, non-cholesterol supplement called creatine monohydrate.
Is Creatine Something New That Scientists Have
Discovered?
While researching the scientific information published about this nutrient,
we were surprised to learn that creatine was first discovered in 1832 by
the French scientist Chevreul. This was way before barbells were invented!
Creatine was first found in meats, and later, in 1847, a sharp observer
noticed that the meat from foxes killed in the wild had ten times as much
creatine as the meat from inactive, domesticated foxes. He concluded that
creatine accumulates in muscles as a consequence of physical activity.
In the early 20th century, it was discovered that not all of the creatine
consumed by humans is excreted in the urine. This led to the recognition
that creatine is, in fact, stored within the body. In 1912, researchers
found that ingesting creatine can dramatically boost the creatine content
of muscle. Then, in 1927, Fiske and Subbarow discovered creatine phosphate,
and determined that creatine is a key player in the metabolism of skeletal
muscle.
Since then, there have been literally thousands of studies published on
creatine. However, most of the studies focusing on creatine and sports
performance have only been done since the early 1990s. It is these studies
that we will focus on in this book.
Who Can Benefit From Creatine?
Although the research on creatine and exercise performance is relatively
new, so far it appears that the greatest benefits occur in those sports
which involve short, intense bursts of energy. That is because these sports
rely most heavily on ATP as an energy source. Athletes in bodybuilding,
powerlifting, martial arts, sprinting, and track and field events such as
javelin and shot-put will greatly benefit due to greater strength. So would
wrestlers, swimmers, football, hockey, basketball and tennis players. We
doubt that creatine will be of any benefit for people who comfortably
cruise on a cart around the golf course and occasionally get up to putt.
Other sports where creatine is not likely to be of any significant benefit
include bowling, skeet shooting and certainly billiards.
It is still unclear whether athletes involved in endurance activities such
as marathon running or long-distance bicycling will benefit from creatine
supplementation. Stroud mentioned anecdotal reports that people in these
sports may benefit, although other studies show that creatine either does
not help or may actually be counterproductive. The difficulty in these
situations appears to center on the increased muscle mass which creatine
provides. While that’s great if you’re a bodybuilder or wrestler, it can be
a detriment if you have to carry all that weight around during a marathon
or triathlon. It becomes a tradeoff between the increased strength you get
from creatine and the increased muscle mass. Further research will provide
us with more definitive answers as to what role creatine can play in
endurance-type sports.
90 And Still Pumping?
Older individuals with decreased muscle mass could also benefit from
creatine supplementation. Since creatine boosts strength and protein
synthesis, it should help to reduce the muscle wasting that can occur with
disease and the aging process. A new study by Earnest also shows that
creatine can reduce cholesterol and lipid levels in the blood, which would
be a major health benefit for everyone. Therefore, creatine may one day
help a large segment of the population to become more physically fit on the
inside and outside.
Is Creatine Safe?
Experiments with the administration of creatine to humans have been going
on for over a century. Dr. Paul Balsom of the Karolinska Institute in
Stockholm, Sweden, is one of the world’s leading experts on creatine. He
states in a review article published in 1994 in Sports Medicine that “to
the best of our knowledge, the only documented adverse effect that has been
associated with creatine supplementation is an increase in body mass.”
We suspect that most athletes will gladly accept this “adverse effect.”
One caution we’d like to make is that the studies which used high dosages
of creatine, such as 20 grams per day, were only a month or less in
duration. As a result, we do not have controlled, scientific studies which
indicate exactly what happens to athletes taking large amounts of creatine
for many months or even years. The only long-term study on creatine to date
provided one gram per day to patients with gyrate atrophy, an eye disorder.
Sipila reported that creatine helped the condition. Therefore, we do not
yet fully know the consequences of high dose, long-term supplementation.
As part of our research for this book, we distributed a detailed survey to
athletes in three states. Personal interviews with men and women who have
used creatine for over a year did not reveal any long-term side effects
which one should be concerned about. Nor is there a particular reason to
think that there should be a problem, given the way in which creatine is
synthesized and excreted by the body. The only short-term side effect
mentioned was diarrhea, which some athletes said occurred when they took
dosages greater than those recommended in this book. The diarrhea went away
when the dosage was reduced.
90 Is It Legal To Use Creatine During
Competition?
At the time of the printing of this book, the International Olympic
Committee has not put creatine on its list of banned substances. This may
be because it is a dietary component of most meats and fish, so it is
difficult to distinguish who is taking oral creatine supplements and who is
just eating more meat. This situation is unlikely to change, so we are
predicting an explosion of creatine use at the Olympics and all
international events in the coming years.