Creatine - Everything you need to know

Creatine is a compound found in muscles of all vertebrates. Creatine is produced naturally in the body on a daily basis by using the amino acid methionine to methylate the combination of the non-essential amino acid’s glycine and arginine. It plays an important role in ensuring rapid release of energy for intense bouts of exercise, such as weightlifting, jumping, throwing, punching, and sprinting. These all utilise creatine in producing the required energy. However, creatine stores are limited.

Benefits of creatine

Increasing total muscle creatine is associated with improvements in power, strength, speed, and lean muscle mass.

Vegetarians or vegans have lower levels of muscle creatine due to the external creatine source being meat and fish. Vegetarians would be advised to supplement with creatine if they are looking to enhance their physical qualities.

Ageing humans are also likely to benefit from creatine supplementation.

Evidence suggests that creatine supplementation may help cognitive function and thereby skill and decision making.

There is no evidence to show negative health implications from creatine. The only suggestion on when long term use of creatine could be a health issue, is if you have an underlying kidney problem.

Understanding the energy currency

ATP (adenosine triphosphate) is the energy currency of the cell and it not stored in large

quantities. Usually having only enough energy for 1-2 seconds of work. Therefore when a muscle contraction occurs, the regeneration of ATP must occur rapidly.

Creatine is known as creatine phosphate. This is because it has an extra phosphate ion attached to the creatine base.

ATP releases energy by transferring a phosphate group to another molecule through a process called phosphorylation. ATP is made up of adenosine and 3 phosphate molecules, and to release energy, one of these phosphates breaks off, which then makes ATP become ADP.

Energy from ATP derives from cleaving the terminal phosphate of the ATP molecule (which is called gamma phosphate). This cleavage is used to power cellular processes. The resulting molecule is adenosine diphosphate (ADP). Creatine phosphate converts ADP back into ATP by donating its phosphate molecule, and in turn, the creatine phosphate forms creatine.

The reaction of creatine phosphate with ADP to form ATP is very rapid but is short lived as the cell does not store high amounts of creatine phosphate. During high intensity contractions, creatine phosphate serves as the major source of energy. This form of energy generation is referred to as anaerobic alactic because it neither produces lactic acid nor requires oxygen.

The use of creatine phosphate is maximal in the first 15 seconds of high intensity exercise and therefore decreases as first glycolysis and then aerobic sources predominate (glucose and triglycerides).

It has been demonstrated that during a 6 second sprint on a cycle ergometer, creatine phosphate contributes approximately 50% of the total ATP production (Boobis, 1987).

Fatigue, in essence is based on the inability to sustain the necessary power output. Excluding factors associated with acidosis, a potential ergogenic aid likely to have an impact on muscle fatigue during intense exercise would be in elevating creatine phosphate through creatine supplementation.

Creatine Research

Creatine has been known as a part of food for over 150 years. However, it was not until the 1990s that significant research into the affects of creatine supplementation on athletic performance was completed.

Creatine is a naturally occurring molecule found mainly in skeletal muscle. It is also found in smaller amounts in the liver, kidney, and brain. Creatine is metabolised in the liver, kidney and pancreas and then transported to the muscles and brain.

Factors such as age, sex and diet all influence muscle creatine concentration. Resting creatine phosphate levels have been shown to be lower in older (60 years) compared with younger (30 years) subjects (smith et al.,1998).

Females have been reported to have an elevated creatine concentration compared with males (Dorsberg et al., 1991).

Diet significantly influences muscle creatine concentration. However due to the external source of creatine coming from foods containing meat and fish, vegetarians may have lower concentrations, which is shown in this study. (Delanghe et al., 1989; Harris et al., 1992).

Muscle creatine loading

Muscle creatine content has been found to increase significantly following creatine ingestion (Harris et al., 1992). Studies have shown that muscle creatine concentrations can be significantly enhanced using lower daily does for a prolonged time period. Hultman et al. (1996) reported that creatine ingestion of 3g per day over a 4 week period produced muscle creatine concentrations similar to those found when 20g per day was taken over a 5 day period. So, creatine ‘loading’ can take place over a concentrated or more prolonged period of time dependent on the dosage per day.

Following the creatine loading phase of 20g per day for 5 days, recommended maintenance doses are considerably lower. Most studies have used doses ranging from 2-5g per day during the maintenance phase in order to ensure the intake matches or is greater than renal excretion. It is important to note that when creatine is no longer ingested, muscle creatine levels diminish to normal after 4 weeks (Greenhaff, 1997;Hultman et al., 1996)

Benefits of Creatine

Creatine supplementation, by increasing both creatine and creatine phosphate, in fibres, should prolong either single bout of high intensity exercise and in particular repeated bouts of high intensity exercise (Greenhaf et al. (1993) and Balsom et al. (1993)

Recent studies in the elderly have shown the potential for significant improvements in strength and lean body mass with creatine ingestion (Tarnopolsky,2008).

Creatine and body composition

Proposed ergogenic effects of creatine supplementation is the increase in lean body mass. This may be due to the fact that creatine increases the muscle water stores therefore leading to enhanced protein synthesis. Of course, the increase in muscle mass could also come from an increase in training intensity brought about by enhanced muscle stores of creatine and creatine phosphate. There is clear evidence in studies which have used resistance training and creatine supplementation, that significant increases in muscle mass have resulted.

Creatine ingestion timing

Ingestion of creatine (0.1g/kg or 8g) immediately before and immediately after resistance training sessions for 12 weeks was shown to increase muscle mass and strength in healthy older adults (Candow et al ., 2014). Likewise, an earlier study in young males observed greater increases in muscle mass and strength with post exercise creatine ingestion. (Antonio and Ciccone, 2013).

Creatine supplementation quantity

One option as previously discussed is a creatine loading method. This typically lasts for 5-7 days, supplementing 20-25g of creatine daily. The typical, most common method would be to start supplementing with 3-5g per day or specifically 0.1g per kg of bodyweight if you want a more accurate dosage.

Creatine and the brain

Cognitive processing may also be affected by creatine metabolism, as it may facilitate ATP homeostasis during periods of rapid or altered brain ATP turnover, such as during complex cognitive tasks, sleep deprivation and some neurological conditions. It is beyond the scope of this article to explore the role of creatine on brain function.

However, creatine supplementation has been shown to somewhat attenuate concussion and brain trauma injuries. Studies have observed positive findings with regard to creatine supplementation for recovery from traumatic brain injury including, reduced duration of post traumatic amnesia (PTA), duration of intubation and intensive care unit stray. Significant improvements were also noted for headaches, dizziness, and fatigue.

Types of creatine

There is no consistent evidence that one form is more beneficial than the other. In many cases, advertisements are a gimmick. I have written out a list of different types of creatine and the differences in order to help you decide on what you think would benefit you most.

Creatine monohydrate- Creatine combined with one water molecule. It is sold this way to help with absorption. By weight, each serving is 90% creatine and 10% water. This can sometimes cause bloating due to water retention and the additional H20 molecules.

Creatine anhydrous- The same base creatine as monohydrate except without the water molecule attached. Each serving is 100% creatine. This is said to potentially cause stomach cramp due to the concentration of creatine.

Creatine HCL- creatine hydrochloride is sold as being more water soluble against the monohydrate version. Promoting the avoidance of stomach issues. (this has not yet been proven)

Kre-alkalyn- This is a PH buffered form of creatine designed to promote better absorption and reduce stomach cramping. However, the strength effects are not proven to be different against the highly researched creatine monohydrate.

Micronized creatine monohydrate- Creatine monohydrate powder that has been mechanically blended to be smaller in particle size than the original form. The theory is that this will help with the speed of absorption.

How to decide which type of creatine to supplement with

When deciding which type of creatine is best for you, take these descriptions into consideration. From my point of view, and many other coaches or nutritionists, I would recommend the highly researched creatine monohydrate.

Potential health implications

Since excess creatine is extracted by the kidneys, consideration from a health perspective should be given to creatine and kidney function.

Conclusion

Supplementation with creatine has been shown to improve both short term and intermittent high intensity exercise, strength, power, increase lean body mass, elevate muscle glycogen stores and enhance brain function (particularly when fatigued). It is important to understand that those considering supplementation should establish a balanced, nutritious diet and optimised hydration as well as the appropriate training methods and recovery protocols to allow the desired adaptation from the training stimulus. Following the loading/ maintenance method if you are looking to supplement creatine or just following the recommended daily intake would be the most efficient way to maximise the effectiveness with a safe dose of creatine.