Indicating another intra-mitochondrial pool of creatine, which seems to play an essential role in the phosphate-transport system from the mitochondria to the cytosol [ 13 ]. Myopathy patients have demonstrated reduced levels of total creatine and phosphocreatine as well as lower levels of CreaT1 protein, which is thought to be a major contributor to these decreased levels [ 14 ].
There is a positive relationship between muscle creatine uptake and exercise performance [ 17 ]. Volek et al [ 18 ] observed a significant increase in strength performance after 12 weeks creatine supplementation with a concurrent periodized heavy resistance training protocol.
These positive effects were attributed to an increased total creatine pool resulting in more rapid adenosine triphosphate ATP regeneration between resistance training sets allowing athletes to maintain a higher training intensity and improve the quality of the workouts along the entire training period. It is regularly reported that creatine supplementation, when combined with heavy resistance training leads to enhanced physical performance, fat free mass, and muscle morphology [ 18 — 22 ].
However, contradicting studies have reported no effects of creatine supplementation on strength performance.
Jakobi et al [ 23 ] found no effects of a short term creatine loading protocol upon isometric elbow flexion force, muscle activation, and recovery process. However, this study did not clearly state if creatine supplementation was administered concurrent with resistance training.
Bemben et al [ 24 ] have shown no additional benefits of creatine alone or combined with whey protein for improving strength and muscle mass after a progressive 14 weeks 3 days per week resistance training program in older men. These conflicting results can be explained by the possibility that the supplemented groups were formed by a greater amount of non-responders or even because creatine supplementation was administered on the training days only 3 times a week.
This strategy has not been adequately tested as effective in middle aged and older men for maintaining post loading elevated creatine stores [ 5 ].
A quantitative, comprehensive scientific summary and view of knowledge up to on the effects of creatine supplementation in athletes and active people was published in a citation review position paper by the International Society of Sports Nutrition [ 5 ].
Saremi et al [ 26 ] reported a change in myogenic transcription factors when creatine supplementation and resistance training are combined in young healthy males. It was found that serum levels of myostatin, a muscle growth inhibitor, were decreased in the creatine group.
Collectively, in spite of a few controversial results, it seems that creatine supplementation combined with resistance training would amplify performance enhancement on maximum and endurance strength as well muscle hypertrophy.
Creatine has demonstrated neuromuscular performance enhancing properties on short duration, predominantly anaerobic, intermittent exercises. A previous meta-analysis [ 28 ] reported an overall creatine supplementation effect size ES of 0.
For this short high-intensity exercise, creatine supplementation resulted in a 7. When looking at the individual selected measures for anaerobic performance the greatest effect of creatine supplementation was observed on the number of repetitions which showed an ES of 0. Furthermore, an increase from base line of The second greatest ES was on the weight lifted at 0.
This would indicate that creatine supplementation might be useful to attenuate fatigue symptoms over multiple bouts of high-intensity, short duration exercise.
The specific aspects of anaerobic endurance performance improved by creatine supplementation were work and power, both of which had a mean ES greater than 0. Cribb et al [ 29 ] observed greater improvements on 1RM, lean body mass, fiber cross sectional area and contractile protein in trained young males when resistance training was combined with a multi-nutrient supplement containing 0. These findings were novel because at the time no other research had noted such improvements in body composition at the cellular and sub cellular level in resistance trained participants supplementing with creatine.
The authors speculated that creatine in addition to a single bout of resistance training can favor an anabolic environment by inducing changes in gene expression after only 5 days of supplementation. When creatine supplementation is combined with heavy resistance training, muscle insulin like growth factor IGF-1 concentration has been shown to increase. Burke et al [ 2 ] examined the effects of an 8 week heavy resistance training protocol combined with a 7 day creatine loading protocol 0.
Additionally, vegetarians within the supplemented group had the largest increase of lean mass compared to non vegetarian 2. Changes in lean mass were positively correlated to the modifications in intramuscular total creatine stores which were also correlated with the modified levels of intramuscular IGF The authors suggested that the rise in muscle IGF-1 content in the creatine group could be due to the higher metabolic demand created by a more intensely performed training session.
These amplifying effects could be caused by the increased total creatine store in working muscles. Even though vegetarians had a greater increase in high energy phosphate content, the IGF-1 levels were similar to the amount observed in the non vegetarian groups.
These findings do not support the observed correlation pattern by which a low essential amino acid content of a typical vegetarian diet should reduce IGF-1 production [ 33 ]. According to authors opinions it is possible that the addition of creatine and subsequent increase in total creatine and phosphocreatine storage might have directly or indirectly stimulated production of muscle IGF-I and muscle protein synthesis, leading to an increased muscle hypertrophy [ 2 ].
Although creatine supplementation has been shown to be more effective on predominantly anaerobic intermittent exercise, there is some evidence of its positive effects on endurance activities. Branch [ 28 ] highlights that endurance activities lasting more than s rely on oxidative phosphorylation as primary energy system supplier.
From this meta analysis [ 28 ], it would appear that the ergogenic potential for creatine supplementation on predominantly aerobic endurance exercise diminishes as the duration of the activity increases over s.
However it is suggested that creatine supplementation may cause a change in substrate utilization during aerobic activity possibly leading to an increase in steady state endurance performance. However, the effects of creatine supplementation on endurance performance have been questioned by some studies. Graef et al [ 35 ] examined the effects of four weeks of creatine citrate supplementation and high-intensity interval training on cardio respiratory fitness.
A greater increase of the ventilatory threshold was observed in the creatine group respect to placebo; however, oxygen consumption showed no significant differences between the groups. The total work presented no interaction and no main effect for time for any of the groups. In addition, of the concern related to the dosage used in these studies, it could be possible that the potential benefits of creatine supplementation on endurance performance were more related to effects of anaerobic threshold localization.
It is suggested [ 16 , 37 ] that another mechanism for the effect of creatine could be enhanced muscle glycogen accumulation and GLUT4 expression, when creatine supplementation is combined with a glycogen depleting exercise. Whereas it has been observed [ 38 ] that creatine supplementation alone does not enhance muscle glycogen storage.
Hickner et al [ 15 ] observed positive effects of creatine supplementation for enhancing initial and maintaining a higher level of muscle glycogen during 2 hours of cycling.
In general, it is accepted that glycogen depleting exercises, such as high intensity or long duration exercise should combine high carbohydrate diets with creatine supplementation to achieve heightened muscle glycogen stores [ 39 ].
Creatine supplementation may also be of benefit to injured athletes. Cooke et al [ 41 ] observed positive effects of a prior 0. The authors speculate that creatine ingestion prior to exercise may enhance calcium buffering capacity of the muscle and reduce calcium-activated proteases which in turn minimize sarcolemma and further influxes of calcium into the muscle. In addition creatine ingestion post exercise would enhance regenerative responses, favoring a more anabolic environment to avoid severe muscle damage and improve the recovery process.
In addition, in vitro studies have demonstrated the antioxidant effects of creatine to remove superoxide anion radicals and peroxinitrite radicals [ 42 ]. This antioxidant effect of creatine has been associated with the presence of Arginine in its molecule. Arginine is also a substrate for nitric oxide synthesis and can increase the production of nitric oxide which has higher vasodilatation properties, and acts as a free radical that modulates metabolism, contractibility and glucose uptake in skeletal muscle.
Other amino acids contained in the creatine molecule such as glycine and methinine may be especially susceptible to free radical oxidation because of sulfhydryl groups [ 42 ]. A more recent in vitro study showed that creatine exerts direct antioxidant activity via a scavenging mechanism in oxidatively injured cultured mammalian cells [ 43 ].
In a recent in vivo study Rhaini et al [ 44 ] showed a positive effect of 7 days of creatine supplementation 4 x 5 g CM 20 g total on 27 recreational resistance trained males to attenuate the oxidation of DNA and lipid peroxidation after a strenuous resistance training protocol. Collectively the above investigations indicate that creatine supplementation can be an effective strategy to maintain total creatine pool during a rehabilitation period after injury as well as to attenuate muscle damage induced by a prolonged endurance training session.
In addition, it seems that creatine can act as an effective antioxidant agent after more intense resistance training sessions. There are two possible theories to explain these effects: 1 Creatine supplementation increases intracellular water content resulting in increased muscle stiffness and resistance to stretch; 2 Neural outflow from the muscle spindles is affected due to an increased volume of the muscle cell.
The authors highlight that the active ROM measures were taken immediately after the loading phase and the reduced active ROM may not be seen after several weeks of maintenance phase [ 45 ]. Hile et al [ 46 ] observed an increase in compartment pressure in the anterior compartment of the lower leg, which may also have been responsible for a reduced active ROM.
Neurological and cognitive function has also been shown to be improved by creatine supplementation [ 47 , 48 ]. Rawson and Venezia [ 49 ] review the effects of creatine supplementation on cognitive function highlighting that higher brain creatine has been associated with improved neuropsychological performance.
Creatine supplementation protocols have been shown to increase brain creatine and phosphocreatine contents. Cognitive processing hindered due to sleep deprivation and natural impairment due to aging can be improved by creatine supplementation.
This review also highlights other possible benefits of creatine ingestion to older adults, such as improvements in: fatigue resistance, strength, muscle mass, bone mineral density, and performance of activities of daily living. Some of these benefits occur without concurrent exercise. However, the ideal dose of creatine to maximize brain uptake is not known. Patients have been supplemented with 40 g while in healthy adults positive results have been reported with around 20 g per day [ 49 ].
Studies with animal and cellular models demonstrated positive effect of creatine ingestion on neurodegenerative diseases. These effects have been attributed to improved overall cellular bioenergetics due to an expansion of the phosphocreatine pool [ 50 ].
Creatine deficiency syndromes, due to deficiency of glycine amidinotransferase and guanidinoacetate methyltransferase, can cause decreases or complete absence of creatine in the central nervous system. Syndromes of this nature have the possibility to be improved by supplementing orally with creatine. Brain creatine deficiency resulting from ineffective crea T1 has been shown not to be effectively treated with oral creatine supplementation [ 51 ].
Additionally, oral creatine administration in patients with myopathies has shown conflicting results depending on the type of myopathy and creatine transport systems disorders [ 4 ].
In a report [ 52 ] conducted on pupils from middle and high school aged 10 — 18 in Westchester County USA 62 of the pupils surveyed were using creatine. The authors found this concerning for 2 main reasons: firstly, the safety of creatine supplementation is not established for this age group and is therefore not recommended. Secondly, it was speculated that taking creatine would lead on to more dangerous performance enhancing products such as anabolic steroids.
It is important to point out that this potential escalation is speculation. Furthermore, a questionnaire was used to determine creatine use amongst this age group and does not necessarily reflect the truth. Due to this, creatine supplementation may benefit the rate and use of creatine phosphate and ATP rephosporylation.
However, performance in short duration high-intensity exercise can be improved through training therefore supplementation may not be necessary [ 54 ]. Based on the limited data on performance and safety, some authors have not identified any conclusions and do not recommend its consumption in regards to creatine supplementation in children and adolescents [ 52 , 54 ].
Other supplementation protocols are also used such as a daily single dose of around 3 — 6 g or between 0. This enhancement in creatine retention would lead to a significantly higher weight gain when people follow a moderate protocol ingestion of several doses of small amounts of CM evenly spread along the day. Syrotuik and Bell [ 57 ] investigated the physical characteristics of responder and non-responder subjects to creatine supplementation in recreationally resistance trained men with no history of CM usage.
The supplement group was asked to ingest a loading dosage of 0. Overall, the supplemented group showed a mean increase in total resting muscle creatine and phosphocreatine of However when looking at individual cases from the creatine group the results showed a variance in response.
From the 11 males in the supplemented group, 3 participants were responders mean increase of Using muscle biopsies of the vastus lateralis, a descending trend for groups and mean percentage fiber type was observed.
Responders showed the greatest percentage of type II fibers followed by quasi responders and non-responders. The responder and quasi responder groups had an initial larger cross sectional area for type I, type IIa and type IIx fibers.
There was evidence of a descending trend for responders to have the highest percentage of type II fibers; furthermore, responders and quasi responders possessed the largest initial cross sectional area of type I, IIa and IIx fibers. Responders were seen to have the lowest initial levels of creatine and phosphocreatine. This would indicate a limit maximum size of the creatine pool.
In summary responders are those individuals with a lower initial level of total muscle creatine content, greater population of type II fibers and possess higher potential to improve performance in response to creatine supplementation. There are several different available forms of creatine: creatine anhydrous which is creatine with the water molecule removed in order to increase the concentration of creatine to a greater amount than that found in CM.
Creatine has been manufactured in salt form: creatine pyruvate, creatine citrate, creatine malate, creatine phosphate, magnesium creatine, creatine oroate, Kre Alkalyn creatine with baking soda.
Creatine can also be manufactured in an ester form. Creatine ethyl ester hydrochloride is an example of this, as is creatine gluconate which is creatine bound to glucose. I've never known anyone to take it for cardio capacity, only muscle gains. I took it years ago and it definitely helped gaining strength. It gave me a little extra push on those last couple reps that I wouldn't have gotten otherwise.
But your kidneys, liver It may have no bad long term side effect I decided it wasn't worth the risk for a little bit of muscle gain. I just gained 10 because I was getting dehydrated all the time due to lower end bodyfat so I think I could stand a few more. I was thinking of giving it to my s. How much did you gain and were you eating for it? Have you seen the effects on a female body with gains? Vitacost usually has the best prices but if you know of something cheaper let me know!
It has been years since I used it so I don't know for sure, but I use to take a lot of Met-Rx products I probably gained 15lbs, went from I didn't really want to gain a lot of weight. The creatine seemed to help with recovery as well. I've never known a woman to take it, but don't know why it wouldn't work in the same manner.
How long have you been taking that? Any bad side effects like stomach upset or headaches? Did it make your body fat go up at all? I thought that the creatine may help the heart muscle too. I am not used to this going so slow and I thought something like that would help muscle, heart and muscles around the joint recover and get stronger faster. I get that couch potato's nausea when I do cardio thats intense sometimes. I'm speaking from personal experience.
Creatine is a type of amino acid found naturally in most types of meat, but it is also available as a dietary supplement with an intended use of improving athletic performance or muscle recovery and growth.
When taken regularly in conjunction with cardiovascular exercise, creatine is useful in reducing the negative physical effects of exercise, improving efficiency during performance and accelerating recovery. Creatine supplementation reduces muscle inflammation during and after exercise when taken regularly. According to a study published in September in "Life Sciences," runners who took creatine supplements for five days prior to a kilometer race demonstrated less cellular damage and less muscular inflammation than runners who were given a placebo.
This suggests that regular creatine supplementation leads to reduced muscle soreness and faster recovery after cardiovascular exercise. One of creatine's most notable potential benefits is facilitating muscle growth, which is an important factor in improving athletic performance. According to a study published in from the Victoria University Research Repository, creatine by itself and creatine combined with whey protein facilitate greater strength gains and muscle growth during resistance training.
Regular resistance training or high-intensity cardiovascular training with creatine supplementation leads to greater strength and increased performance.
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