Creatine
is a naturally occurring compound found in large amounts in skeletal muscle and
brain as a result of dietary intake and endogenous synthesis from amino acids.
Dietary intake from animal muscle (e.g. meat, fish) is 1-2 g/d or half the
daily turnover. Muscle creatine content varies between individuals, perhaps
related to gender, age or fibre type. Vegetarians do not consume a dietary
source of creatine and are reliant on body synthesis of creatine; studies have
shown that vegetarians have lower residual muscle creatine concentrations than people
that eat meat.
Phosphorylated creatine
provides a number of important functions related to fuel supply in the muscle.
The most well-known role is as a source of phosphate to regenerate ATP. The
phosphocreatine system is the most important fuel source for sprints or bouts
of high-intensity exercise lasting up to 10 seconds. Creatine supplementation
has been shown to enhance the performance of exercise involving repeated
sprints or bouts of high intensity exercise, separated by short recovery
intervals. Therefore, competition or training programs involving intermittent
high-intensity work patterns with brief recovery periods of less than 1 minute,
or resistance training programs may be enhanced by creatine loading.
Performance enhancements may be
seen as a result of an acute loading program, but chronic creatine use to
promote superior training adaptations may offer the greatest benefits. Studies
have shown that prior creatine loading enhances glycogen storage and
carbohydrate loading in a trained muscle. The performance implications of this finding
have not been studied well, Although there is a lot of findings by individual
athletes supporting the benefits of creatine supplementation on exercise
capacity and performance. In saying that most of the findings weren’t done by
the AIS and or its elite athletes. They were conduct by bodybuilders and other sportsman where the
intake of creatine supplement help them with their gains, but it may not necessarily
work for every individual due to that we all have different body types and how
we break down and absorb the supplement.
There are findings that show
that creatine supplementation aids in therapeutic methods for a number of disorders including muscular
dystrophy, polymyositis, ageing, Parkinson’s disease and Huntingdon’s disease.
Consuming creatine doses with a
substantial 50-100g amount of carbohydrate enhances creatine uptake and storage
into the muscle. Taking creatine doses with a carbohydrate-rich meal or snack
may help all individuals to respond to creatine supplementation and reach the
muscle creatine storage threshold. A weight gain of 600g to 1kg is typically
associated with acute loading and may represent water retention. Although it
has been suggested that the slow loading protocol may circumvent this weight
gain, this theory has not been properly studied. It is possible that any weight
changes associated with slow loading are masked by normal body mass
fluctuations or the outcomes of longer term training and the diet in the
individual.
Many
athletes who use creatine either are unaware of correct supplementation
protocols or persist in using unnecessarily high doses of creatine. Studies
show that high doses of creatine do not further enhance creatine stores. This
weight gain associated with creatine loading may be counterproductive to
athletes competing in sports where power-to-weight is a key factor in
successful performance or in sports involving weight divisions. The long-term
consequences of creatine use are considered to be unknown, although there is
now a 20 year history of creatine supplement use with few reports of adverse
outcomes. There are many reports of an increased risk of muscle cramps, strains
and tears, but studies to date have not reported an increased risk of these
events. In fact, several studies show a reduced prevalence of muscle
cramps and tears and enhanced thermoregulation during prolonged exercise
in the heat in creatine users compared to a group receiving a placebo
treatment. Some individuals experience mild side-effects from creatine
supplements in the form of gastrointestinal discomfort or an increased
prevalence of headaches.
References
AIS group A Supplements –
Creatine
Examine.com/Creatine