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Protein For Muscles Essay, Research Paper

Creatine Information Creatine is a naturally occurring metabolite found in

muscle tissue. It plays an important role in energy metabolism, and ATP

reformulating. Muscle soreness, lactate build up, and fatigue are a direct

result of depleted ATP store. Creatine replenishes ATP stores, thus prolonging

time to fatigue. Creatine also increases available instant energy, increases

muscular strength, improves endurance, and reduces levels of metabolic

byproducts such as ammonia (Ammonia is produced at high levels during intense

exercise, ammonia is partially responsible for muscular fatigue). From our

experience, Creatine supplementation results in significant muscle accumulation

and increased muscular endurance in all of our clients. Weight gains from 4-14

pounds are common place with Creatine supplementation. Creatine loading via

supplemental feeding can also offer the potential for the following. Improved

Athletic Performance: Maximizing the level of stored Creatine (20% or more) by

supplemental ingestion of Creatine Monohydrate, has been shown to extend peak

athletic performance for longer periods during short duration, high intensity

exercise. Stockpiling Creatine shortens the time necessary for the body to

generate replacement Creatine, thus significantly reducing muscle recovery time

between short duration, high intensity activities. Increase Lean Muscle Mass:

Inactive or dystrophic muscle (such as occurs as a result of injury) has by

nature reduced levels of Creatine. Supplementation with Creatine Monohydrate

permits dystrophic muscle to work harder during therapy and rebuild itself to

its normal state. Correct Creatine Deficiencies: Disease or age-related Creatine

deficiencies in the brain and skeletal muscle can be improved by the oral

administration of Creatine Monohydrate, helping to restore a more active, normal

lifestyle. How to Use Creatine Loading / Maintenance Phase: Take one to two

scoops immediatley after workout, that’s it. Creatine is best utilized when

taken with a high glycemic substance such as (grape juice, Ultra fuel, ect.)

Creatine Monohydrate – How Does It Really Works? Glenn Peden offered the

following from Tom McCullough via the FEMUSCLE list on Tuesday, 13June1995. It

was forwarded to me in response to my call for information on Creatine. Glenn:

My Dad said he read mail today. Hope he can answer all of your questions. I have

been powerlifting for 13 years. I lift in the 242 lb. weight class. I am also

ranked #9 in the USA. If you have not tried the creatine monohydrate, get some.

Just a quick explanation of its actions. I’m sure you know in order for a muscle

to contract energy has to be released through the breakdown of ATP. In strength

training you are in an anaerobic system. The only way ATP is made is through

anaerobic glycolisis. ATP is also reformed in the anaerobic system when chemical

reactions take place in the muscle forcing the biproducts of ATP breakdown (ADP

+ Pi) back together so muscular contractions can take place again. Here is where

the creatine comes in to play. The body has to hace creatine phosphate to force

the ADP + Pi back together to reform ATP for energy. Creatine phosphate is

formed when a chemical reaction breaks down creatine monohydrate, a natural

dietary substance found in meats. The liver can synthesise creatine in small

amounts but most of the creatine we digest is stored in the muscles and bones

for future use. However, especially in diets low in protein, we do have limited

stores and it does take time to release the creatine stores. Red meat is the

best source of creatine,however there is only about 1 g./lb. of meat. By taking

creatine supplements you are supersaturating the body with creatine phosphate

stores. This will enable you to have more creatine available to produce more ATP

at a faster rate. Thus, more energy is available per muscular contraction and

ATP stores are restores quicker. This means for weight lifters more max strength

and quicker recovery. The instructions for supplementation: 1st 5 days: 5g.4-6 x

per day (this is the loading phase) after: 5-8g 30-45 min before workout/ 5g.

after workout. Creatine supplements will also cause, in most individuals intra

cellular fluid retention. I have experienced 10 lb weight gains in first 2 wks.

You should also start experiencing strength gains after the first week. These

gains wont be dramatic, like steriods, but you will see a difference. Try it , I

think you will like it. Texas A&M experimented with it with a few players

last season. This season they are putting the whole team on it because they got

such positive results with the few guys who tried it. promote further gains in

sprint performance (5-8%), as well as gains in strength (5-15%) and lean body

mass (1-3%). The only known side effect is increased body weight. More research

is needed on individual differences in the response to creatine, periodic or

cyclical use of creatine, side effects, and long-term effects on endurance.

Reviewers’ comments Introduction Creatine is an amino acid, like the building

blocks that make up proteins. Creatine in the form of phosphocreatine (creatine

phosphate) is an important store of energy in muscle cells. During intense

exercise lasting around half a minute, phosphocreatine is broken down to

creatine and phosphate, and the energy released is used to regenerate the

primary source of energy, adenosine triphosphate (ATP). Output power drops as

phosphocreatine becomes depleted, because ATP cannot be regenerated fast enough

to meet the demand of the exercise. It follows that a bigger store of

phosphocreatine in muscle should reduce fatigue during sprinting. Extra creatine

in the muscle may also increase the rate of regeneration of phosphocreatine

following sprints, which should mean less fatigue with repeated bursts of

activity in training or in many sport competitions. So much for the theory, but

can you get a bigger store of creatine and phosphocreatine in muscle? Yes, and

it does enhance sprint performance, especially repeated sprints. Extra creatine

is therefore ergogenic, because it may help generate more power output during

intense exercise. In addition, long term creatine supplementation produces

greater gains in strength and sprint performance and may increase lean body

mass. In this article I’ll summarize the evidence for and against these claims.

I’ll draw on about 42 refereed research papers and four academic reviews to make

conclusions regarding the ergogenic value of creatine supplementation. In

addition, I’ll provide 25 references to studies published in abstract form,

which report the most recent preliminary findings on creatine supplementation.

Effects of Creatine Supplements on Muscle Creatine, Phosphocreatine, and ATP The

daily turnover of creatine is about 2 g for a 70 kg person. About half of the

daily needs of creatine are provided by the body synthesizing creatine from

amino acids. The remaining daily need of creatine is obtained from the diet.

Meat or fish are the best natural sources. For example, there is about 1 g of

creatine in 250 g (half a pound) of raw meat. Dietary supplementation with

synthetic creatine is the primary way athletes "load" the muscle with

creatine. Daily doses of 20 g of creatine for 5-7 days usually increase the

total creatine content in muscle by 10-25%. About one-third of the extra

creatine in muscle is in the form of phosphocreatine (Harris, 1992; Balsom et

al., 1995). Extra creatine in muscle does not appear to increase the resting

concentration of ATP, but it appears to help maintain ATP concentrations during

a single maximal effort sprint. It may also enhance the rate of ATP and

phosphocreatine resynthesis following intense exercise (Greenhaff et al., 1993a;

Balsom et al., 1995; Casey et al., 1996). There is some evidence that not all

subjects respond to creatine supplementation. For example, one study reported

that subjects who experienced less of a change in resting muscle creatine (*20

mmol/kg dry mass) did not appear to benefit from creatine supplementation (Greenhaff

et al., 1994). However, more recent studies indicate that taking creatine with

large amounts of glucose increases muscle creatine content by 10% more than when

creatine is taken alone (Green et al., 1996a; Green et al., 1996b).

Consequently, ingesting creatine with glucose may increase its ergogenic effect.

Effects on Performance Researchers first investigated the ergogenic effects of

short-term creatine loading. In a typical study, a creatine dose of 5 g is given

four times a day for five to seven days to ensure that muscle creatine

increases. A control group is given a placebo (glucose or some other relatively

inert substance) in a double-blind manner (neither the athletes nor the

researchers doing the testing know who gets what until after the tests are

performed). Most studies have shown that speed or power output in

sprints–all-out bursts of activity lasting a few seconds to several minutes–is

enhanced, typically by 5-8%. Repetitive sprint performance is also enhanced when

the rests between sprints don’t allow full recovery. In this case, total work

output can be increased by 5-15%. There is also evidence that work performed

during sets of multiple repetition strength tests may be enhanced by creatine

supplementation, typically by 5-15%. In addition, one-repetition maximum

strength and vertical-jump performance may also be increased with creatine

supplementation, typically by 5-10%. The improvement in exercise performance has

been correlated with the degree in which creatine is stored in the muscle

following creatine supplementation, particularly in Type II muscle fibers (Casey

et al., 1996). Researchers have now turned their attention to longer-term

creatine supplementation. In these studies, a week of creatine loading of up to

25 g per day is followed by up to three months of maintenance with reduced or

similar dosages (2-25 g per day). Training continues as usual in a group given

creatine and in a control group given a placebo. Greater gains are now seen in

performance of single-effort sprints, repeated sprints, and strength (5-15%).

Table 1 at the end of this article lists the references to positive effects of

creatine on performance. Theoretically, creatine may affect performance through

one or more of the following mechanisms (Table 2): an increase in concentrations

of creatine and phosphocreatine in resting muscle cells; an increased rate of

resynthesis of phosphocreatine between bouts of activity; enhanced metabolic

efficiency (lower production of lactate, ammonia, and/or hypoxanthine); and

enhanced adaptations through higher training loads. Creatine supplementation

during training may also promote greater gains in lean body mass (see Body

Composition below). Not all studies have reported ergogenic benefit of creatine

supplementation (Table 3). In this regard, a number of equally well-controlled

studies indicate that creatine supplementation does not enhance: single or

repetitive sprint performance; work performed during sets of maximal effort

muscle contractions; maximal strength; or, submaximal endurance exercise. What’s

more, one study reported that endurance running speed was slower, possibly

because of an increase in body mass (Balsom et al., 1993b). In analysis of these

studies, creatine supplementation appears to be less effective in the following

situations: when less than 20 g per day was used for 5 days or less; when low

doses (2-3 g per day) were used without an initial high-dose loading period; in

crossover studies with insufficient time (less than 5 weeks) to allow washout of

the creatine; in studies with relatively small numbers of subjects; and when

repeated sprints were performed with very short or very long recovery periods

between sprints. It is also possible that subject variability in response to

creatine supplementation may account for the lack of ergogenic benefit reported

in these studies. In addition, there have been reports that caffeine may negate

the benefit of creatine supplementation (Vandenberghe et al., 1996).

Consequently, although most studies indicate that creatine supplementation may

improve performance, creatine supplementation may not provide ergogenic value

for everyone. Body Composition Although some studies have found no effect, most

indicate that short-term creatine supplementation increases total body mass, by

0.7 to 1.6 kg. With longer use, gains of up to 3 kg more than in matched control

groups have been reported (see Table 4 at the end of this article for

references). For example, Kreider et al.(1998) reported that 28 days of creatine

supplementation (16 g per day) resulted in a 1.1 kg greater gain in lean body

mass in college football players undergoing off-season resistance/agility

training. In addition, Vandenberghe et al. (1997) reported that untrained

females ingesting creatine (20 g per day for 4 days followed by 5 g per day for

66 days) during resistance training observed significantly greater gains in lean

body mass (1.0 kg) than subjects ingesting a placebo during training. The gains

in lean body mass were maintained while ingesting creatine (5 g per day) during

a 10-week period of detraining and in the four weeks after supplementation

stopped. Findings like these suggest that creatine supplementation may promote

gains in lean body mass during training, but we don’t yet understand how it

works. The two prevailing theories are that creatine supplementation promotes

either water retention or protein synthesis. More research is needed before we

can be certain about the contribution each of these processes makes to the

weight gain. Side Effects In studies of preoperative and post-operative

patients, untrained subjects, and elite athletes, and with dosages of 1.5 to 25

g per day for up to a year, the only side effect has been weight gain (Balsom,

Soderlund & Ekblom, 1994). Even so, concern about possible side effects has

been mentioned in lay publications and mailing lists. Before discussing these

possible side effects, it should be noted that they emanate from unsubstantiated

anecdotal reports and may be unrelated to creatine supplementation. We must be

careful to base comments regarding side effects of creatine supplementation on

factual evidence, not speculation. But we must also understand that few studies

have directly investigated any side effects of creatine supplementation.

Consequently, discussion about possible side effects is warranted. Anecdotal

reports from some athletic trainers and coaches suggest that creatine

supplementation may promote a greater incidence of muscle strains or pulls.

Theoretically, the gains in strength and body mass may place additional stress

on bone, joints and ligaments. Yet no study has documented an increased rate of

injury following creatine supplementation, even though many of these studies

evaluated highly trained athletes during heavy training periods. Athletes

apparently adapt to the increase in strength, which is modest and gradual. There

have been some anecdotal claims that athletes training hard in hot or humid

conditions experience severe muscle cramps when taking creatine, and the cramps

have been attributed to overheating and./or changes in the amount of water or

salts in muscle. But no study has reported that creatine supplementation causes

any cramping, dehydration, or changes in salt concentrations, even though some

studies have evaluated highly trained athletes undergoing intense training in

hot/humid environments. In my experience with athletes training in the heat

(e.g., during 2-a-day football practice in autumn), cramping is related to

muscular fatigue and dehydration while exercising in the heat. It is not related

to creatine supplementation. Nevertheless, athletes taking creatine while

training in hot and humid environments should be aware of this possible side

effect and take additional precautions to prevent dehydration. Some concern has

been raised regarding the effects of creatine supplementation on kidney

function. The body seems to be able to dispose of the extra creatine without any

problem (Poortmans et al., 1997). The extra creatine is eliminated mainly in the

urine as creatine, with small amounts broken down and excreted as creatinine or

urea. No study has shown that creatine supplementation results in clinically

significant increases in liver damage or impaired liver function. It has also

been suggested that creatine supplementation could suppress the body’s own

creatine synthesis. Studies have reported that it takes about four weeks after

cessation of creatine supplementation for muscle creatine (Vandenberghe et al.,

1997) and phosphocreatine (Febbraio et al., 1995) content to return to normal.

It is unclear whether muscle the content falls below normal thereafter. Although

more research is needed, there is no evidence that creatine supplementation

causes a long-term suppression of creatine synthesis when supplementation stops

(Balsom, Soderlund & Ekblom, 1994; Hultman et al., 1996). Does creatine

supplementation have undiscovered long-term side effects? Trials lasting more

than a year have not been performed, but creatine has been used as a nutritional

supplement for over 10 years. Although long-term side effects cannot discounted,

no significant short-term side effects other than weight gain have been

reported. In addition, I am not aware of any significant medical complications

that have been linked to creatine supplementation. Furthermore, creatine and

phosphocreatine have been used medically to reduce muscle wasting after surgery

and to improve heart function and exercise capacity in people with ischemic

heart disease (Pauletto & Strumia, 1996; Gordon et al., 1995). Creatine

supplementation may even reduce the risk of heart disease by improving blood

lipids (Earnest, Almada & Mitchell, 1996; Kreider et al., 1998). On the

basis of the available research, I consider creatine supplementation to be a

medically safe practice when taken at dosages described in the literature.

Determining whether creatine supplementation has any short- or long-term side

effects is an area receiving additional research attention. If there are side

effects from long-term creatine supplementation, an important issue will be the

liability of coaches, trainers, universities, and athletic governing bodies who

provide creatine to their athletes. Anyone advising athletes to take creatine

should make it clear that side effects from long-term use cannot be completely

ruled out, and that the athletes do not have to take the supplements. It would

be wise to have a formal policy for dosages to reduce the chances of athletes

taking excessive amounts. Ethics Creatine supplementation is not banned, but is

a nutritional practice that enhances performance nevertheless unethical? Anyone

pondering this question should consider that creatine supplementation is a

practice similar to carbohydrate loading, which is well accepted. Some are also

concerned that creatine supplementation could cause a carryover effect, whereby

athletes who have learned to take creatine are more likely to use dangerous or

banned substances. Proper education among athletes, coaches, and trainers

regarding acceptable and unacceptable nutritional practices is probably the best

way to reduce any carryover. How to Use Creatine A typical loading regime for a

70-kg athlete is a 5-g dose four times a day for a week. Thereafter the dose can

be reduced to 2 to 5 g per day in order to maintain elevated creatine content.

This supplementation protocol will increase intramuscular creatine and

phosphocreatine content and enhance high intensity exercise performance. There

is now some evidence that taking glucose (100 g) with the creatine (5 to 7 g)

increases the uptake of creatine into muscle (Green et al., 1996a; Green et al.,

1996b). Consequently, I recommend that athletes take creatine with carbohydrate

(e.g. with grape juice) or ingest commercially available creatine supplements

that combine creatine with glucose. For athletes wanting to promote additional

gains in lean body mass, I recommend 15 to 25 g per day for 1 to 3 months.

Although many athletes cycle on or off creatine, no study has determined whether

this practice promotes greater gains in fat free mass or performance than

continuous use. More research is needed here. Creatine supplements are good

value. Creatine is now being sold for as little as US$30 per kg, or about $0.60

per day when taking 20 g per day. Popular sports drinks are more expensive.


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