Sports supplementation has become a very popular
aid for athletes. Over the years, new supplements have come and
gone with only a small percentage standing the test of time.
Debates and controversy have arisen over the safety and effectiveness
of a variety of ergogenic aids. This has led to the banning of
certain performance enhancing substances. However, there are
still those few that have proven to be legal, safe, and effective
to the point that many high performance athletes have chosen
to implement them into their nutrition program and training routine.
Creatine has been one of the most popular and widely used supplements
for over a decade. Although its effectiveness and safety have
both been questioned over the years, there is a great deal of
conclusive research and evidence that gives fair reason for athletes
to supplement with this product. Creatine monohydrate is also
considered by many to be the most popular and effective legal
bodybuilding supplements on the market.
There are specifically three major forms of creatine: monohydrate,
micronized, and ethyl-ester. Creatine monohydrate is creatine
in its raw and most basic form. Creatine ethyl ester is creatine
monohydrate with an ester attached, which is rumored to have
the highest absorption rate. Micronized creatine has smaller
particles of creatine with 20 times more total surface area for
greater uptake into the bloodstream and a greater absorption
rate. Once creatine is synthesized in the body, it is then transported
through the bloodstream to the muscles where it plays a pivotal
role in energy metabolism. One of the central theories behind
creatine usage is based on the scientific theories of ADP being
converted to ATP. ATP is the primary energy source for the body's
working muscles during intense exercise. Therefore, during periods
of high intensity anaerobic work, lack of ATP seems to be the
limiting factor in terms of being able to continue high intensity
exercise in an efficient manner. When the body is incapable of
producing ATP, large amounts of ADP can be used for fuel to create
ATP if an extra phosphate is added to the ADP. Thus, creatine
is the method for adding this extra phosphate, which ultimately
leads to an increased supply of ATP, which is beneficial for
high level performance (1).
There are many claims surrounding creatine as being an advanced
muscle building product. These claims are based on the theories
of increased ATP re-synthesis from ADP as previously mentioned
(1). Supplement companies also claim that higher levels of ATP
lead to greater amounts of work being achieved during resistance
training in high intensity anaerobic work. This leads to increased
surface area of the muscle due to an increased rate of protein
synthesis that is achieved through higher musculoskeletal workloads.
One of the most common claims surrounding creatine is its cell
volumizing effect. This is also known as increased water retention,
especially among skeptics. However, proponents of this supplement
are convinced that this cell volumizing effect is a necessary
component for any increase in muscle hypertrophy. Supposedly,
when the muscle is volumized, it is forced to expand via added
surface area in order to accommodate the extra fluids in the
For the purposes of this literature review, the research cited
and reviewed will be focused on creatine monohydrate due to the
fact that most of the present research has been isolated to this
form of creatine. However, this does not negate the fact that
micronized and ethyl ester creatines are just as effective, if
not more so than creatine monohydrate.
There have been countless studies relating to creatine and its
impact on physical performance. Most studies have examined the
impact on strength, muscular hypertrophy, power and speed, or
endurance training. In a double blind study performed by Kreider
et al (2) in which 16 physical education students performed 10
bouts of 6 seconds each on a stationary cycle with 30-second
rest periods between individual bouts, the findings were significant.
The results showed that individuals who took 20 g of creatine
for 6 days were far more capable of maintaining cycle speed.
Similar results were seen in many other studies of repeated high-intensity
exercise as noted by the author.
In a double-blind study by Kreider et al (3) performed on 52
collegiate football players over a period of 28 days, the results
were also positive. It was found that those who supplemented
with creatine and creatine plus beta-hydroxy beta-methylbutyrate
(HMB) had greater increases in lean muscle and bone mass compared
to the placebo group.
In another study performed on 33 collegiate football players
undergoing a 10-wk resistance training program, results showed
that creatine had a greater increase in strength, muscle mass,
and certain beneficial hormonal changes compared to the placebo
group. Specifically, those who supplemented creatine with beta-alanine
had the greatest increase in muscle mass. Also, the creatine
only group and the creatine plus beta-alanine group had far greater
increases in strength, muscle mass, IGF, and body fat composition
than the placebo group. Therefore, this study shows that although
creatine has a very positive effect on physiological markers
of human performance, it appears its effectiveness is maximized
when combined with other forms of supplementation such as beta-alanine.
Also of further note is that recent claims by supplement companies
have been marketing beta-alanine and creatine combinations as
the greatest method of supplementing with creatine.
In a study performed by Izquierdo et al (4), a group of 19 trained
athletes underwent a study to determine the effects of creatine
supplementation (20 grams a day for 5 days) on maximal strength,
muscle power production during repetitive high-power-output exercise
bouts, repeated running sprints, and other markers of exercise
performance. The results showed that creatine supplementation
significantly increased body mass, number of repetitions performed
to fatigue, and total average power output values. Creatine supplementation
also had a positive impact on the average running times during
the first 5 meters of the six repeated 15-m sprints.
In conclusion, this study showed that short-term creatine supplementation
leads to significant improvements in lower body maximal strength,
maximal repetitive upper and lower body high power exercise bouts,
and muscular endurance. Further results also indicated enhanced
repeated sprint performance and reduced fatigue in the vertical
jump test following bouts of high intensity exercise. However,
contrary to most scientific findings such as those found in a
study performed by Zoeller et al (5), this study did not show
any improvements in aerobic endurance or aerobic capacity with
creatine supplementation which may be due to the short term duration
of this study. On the other hand, Zoeller et al.'s (5) study
showed an increase in aerobic endurance with four weeks of creatine
Although these findings seem one sided and highly optimistic,
there are numerous other studies which support the previous conclusions.
In a study performed by Kilduff et al (6), five days of creatine
supplementation increased body weight and fat-free body mass
in resistance trained men who were classified as responders.
Maximal strength and total force output during a repeated maximal
isometric bench press test were also significantly greater in
the creatine group compared to the placebo group. Yet, another
study by Preen et al (7) indicated that creatine ingestion of
20 grams a day for only five days improved exercise performance
during 80 min of repeated sprint exercise. The author goes on
to note that this may be due an increased total creatine store
and an improved replenishment rate of phosphocreatine, which
is a common theory behind creatine supplementation.
Peeters et al. (8) noticed that creatine supplementation appears
to increase strength and lean body mass when combined with a
resistance training program. Increases in strength may be attributed
to an increase in intramuscular phosphocreatine stores that are
used to replenish ATP during high-intensity exercise. Furthermore,
the gains observed with regard to lean body mass may be due to
an increase in muscle protein synthesis and cell volumizing that
occurs within the muscle cells (9). Thus, strength training athletes
who desire gains in strength and lean body mass may benefit from
creatine supplementation (e.g., football players, bodybuilders,
and power lifters). Furthermore Peeters et al. found that creatine
supplementation was also beneficial for endurance athletes.
Terjung et al. (10) noticed that short-term creatine supplementation
(5-7 days of 20 grams a day) can lead to an improvement in performance.
Most, but not all of the studies indicate that creatine supplementation
significantly enhances the ability to produce higher muscular
force and/or power. Terjung et al. (10) also noted that the greatest
improvements in performance seem to be found during a series
of repetitive high power output exercise bouts. These increased
by 5-20% over that measured for the placebo group. These experimental
protocols typically employed exceptionally high-power output
efforts (e.g., maximal cycling and/or power jumping that can
be maintained for only a short period, usually seconds) separated
by fairly brief periods of rest (e.g., 20-60 s). As discussed
above, these are the exercise conditions where the transitional
energy contribution from PCr is likely most significant.
Rawson et al. (11) noted that even though there is considerable
variability in the increase in muscle strength and weightlifting
performance in subjects ingesting creatine during resistance
training, subjects ingesting creatine experience an average of
8% greater increase in muscle strength than the placebo group
(20% vs. 12%) and a 14% greater increase in weightlifting performance
(26% vs. 12%). Additionally, untrained subjects experienced a
larger increase in muscle strength following creatine supplementation
plus resistance training than trained subjects (31% vs. 14%).
Furthermore, Flanagan et al. (12) found that creatine supplementation
will not increase the maximal contraction velocity or the peak
power production of muscle in the non-fatigued state. Therefore,
weightlifters should be aware that supplementation will not suddenly,
directly increase their maximum in the snatch or clean and jerk.
However, Flanagan et al. noted that creatine supplementation
will delay fatigue, facilitate recovery, and increase power output
in the later stages of training. This will allow the weightlifter
to perform a greater workload in each training session, which
over time will assist in increasing performance in maximum effort
lifts. Creatine supplementation is of particular benefit during
high-intensity, fatigue-inducing, and high-volume training phases.
Therefore, from Flanagan et al.'s findings, it appears that creatine
supplementation has been demonstrated to enhance performance
when the PCr energy pathway is heavily taxed. Thus, supplementation
will benefit weightlifters most when they are in periods of training
where considerable muscular fatigue is induced.
From the above studies and others of similar context, it appears
there are several effective ways of supplementing with creatine.
The most common, seems to be a loading period of 20 grams a day
for five days followed by a maintenance phase of 3-5 grams a
day for 4-6 weeks or longer. Although there are many other dosage
recommendations for creatine, more research is needed in order
to finalize such theory and speculation. This is especially true
with the insurgence of micronized and ethyl ester creatine as
the claims of higher absorption rates and smaller dosages has
been advocated. It also appears that creatine taken in conjunction
with either beta-alanine (a fatigue and lactic acid buffering
agent) or HMB (an anabolic compound), maximizes the effectiveness
of the product in order to produce maximal gains in human performance.
Summary and Recommendation
After thoroughly examining the effects of creatine and the
literature surrounding it, there appears to be conclusive evidence
that creatine supplementation has a significant positive effect
on human performance. These improvements from creatine supplementation
are seen through increased lean muscle mass, increased strength
and power, improvements in speed and single effort sprint performances,
as well as anaerobic endurance. It also appears that, creatine
when combined with either beta-alanine or HMB has the greatest
positive impact on markers of physiological performance. Although
creatine is considered a safe form of supplementation, there
may be a concern for people with pre-existing kidney issues,
as well as though who are taking ephedra or caffeine products
(13). However, there has been very little scientific evidence
to back up these warning claims. There also appear to be no signs
of toxicity from supplementation with creatine when moderate
to slightly higher doses are used.
There are two scientifically proven ways to supplement with creatine.
The first is through a loading phase, in which 20 grams is taken
for 5-7 days, followed by a maintenance phase of 3-5 grams a
day for periods of 2-3 months at a time. The second form of supplementation
is a simple protocol. That is to supplement with 3-10 grams of
creatine per day for a period of 2-3 months with no loading phase.
It is generally recommended to take at least 1-2 weeks off from
creatine supplementation in order to maintain a proper response
mechanism in the body.
There are also current rumors among many bodybuilding professional
that cycling creatine, such as 20 grams daily for a period of
three days immediately followed by three days of non supplementation
may be the most effective form of creatine supplementation. This
process is continued for 8-10 weeks. This ensures that the cells
in the body do not down-regulate and grow immune to creatine's
presence in the body. However, greater research is needed to
justify this cycling protocol. Creatine should also be taken
with 20-90 grams of simple sugars along with large volumes of
water for more rapid absorption into the muscle tissues. Lastly,
consuming a small dose of creatine immediately before and after
the workout may be the most appropriate times for supplementation.
On off days, morning and mid-day are recommended.
According to consumerlab.com (13) and other valid sources, some
of the best creatine products on the market include: Muscletech
Cell-Tech, BSN Cell Mass, EAS Phosphagen, Everlast Nutrition
Premium Creatine, Phosphate Complex, GNC Pro Performance Creatine,
and ISS Complete Creatine. Liquid forms of creatine should generally
be avoided due to the breakdown that may occur when in this state
for excess time. Creatine cocktails (creatine products combined
with other cell volumizing compounds) have also received a great
amount of hype and publicity due to numerous claims of extreme
effectiveness. However, there has been very little research on
these products. Some of the more well noted creatine cocktails
are NxLabs Anavol, BSN NO-Xplode, Controlled Labs Green Magnitude,
and Muscletech NanoVapor.
1. Clark F, Joseph. Creatine and Phosphocreatine: A Review
of Their Use in Exercise and Sport. Journal of Athletic Training.
1997. Jan-Mar; 32(1): 45-51.
2. Kreider, Richard B.; Ferreira, Maria; Wilson, Michael;
Grindstaff, Pamela; Plisk, Steven; Reinardy, Jeff; Cantler, Edward;
Almada, A. L. Effects of creatine supplementation on body composition,
strength, and sprint performance. Medicine & Science in Sports
& Exercise. 30(1):73-82, January 1998.
3. Kreider RB. Dietary supplements and the promotion of muscle
growth with resistance exercise. Sports Med. 1999; 27:97-110.
4. Izquierdo M, Ibanez J, Gonzalez-Badillo JJ, Gorostiaga
EM. Effects of creatine supplementation on muscle power, endurance,
and sprint performance. Med Sci Sports Exerc. 2002 Feb; 34: 332-43.
5. Zoeller RF, Stout JR, O'kroy JA, Torok DJ, Mielke M. Effects
of 28 days of beta-alanine and creatine monohydrate supplementation
on aerobic power, ventilatory and lactate thresholds, and time
to exhaustion. Amino Acids. 2006 Sep 5.
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P, Parker M, Paul L, Pitsiladis YP. Effects of creatine on isometric
bench-press performance in resistance-trained humans. Med Sci
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S. Effect of creatine loading on long-term sprint exercise performance
and metabolism. Med Sci Sports Exercise. 2001 May; 33: 814-21.
8. Peeters M, Brian, Lantz D, Christopher, And Mayhew L, Jerry.
Effect of Oral Creatine Monohydrate and Creatine Phosphate Supplementation
on Maximal Strength Indices, Body Composition, and Blood Pressure.
The Journal of Strength and Conditioning Research: 1999. Vol.
13, No. 1, pp. 3-9.
9. YeanSub L, Jon. The Effects of Creatine Supplementation
on Body Composition, Muscular Strength and Power. United States
Sports Academy, The Sports Journal, 2000.
10. Terjung Ronald, Clarkson, Priscilla, Eichner E, Randy,
Greenhaff L, Paul, Hespel J, Peter. The physiological and health
effects of oral creatine supplementation. Journal of the Amercian
College of Sports Medicine. Vol. 32, No. 3, pp. 706-717, 2000.
11. Rawson S, Eric, Volek S, Jeff. Effects of Creatine Supplementation
and Resistance Training on Muscle Strength and Weightlifting
Performance. The Journal of Strength and Conditioning Research:
2003. Vol. 17, No. 4, pp. 822-831.
12. Flanagan P, Eamonn. Creatine Supplementation: Implications
for the Competitive Weightlifter. Strength and Conditioning Journal:
2007. Vol. 29, No. 2, pp. 60-66.
13. www.consumerlab.com. Creatine.