Creatine - A Must Have Supplement?

What is Creatine?

Creatine is an organic nitrogen-containing compound, yet it is not a protein. It is mainly acquired through diet via the intake of red and white meat as well as fish (1). Usually, a typical diet containing meat consists of around 1-2g of creatine per day with the average 70kg male containing a total pool of around 120g (1–3). Creatine is also produced endogenously within the body, yet only around 1g is synthesised this way per day (1). Creatine is frequently taken as a sports supplement, yet despite its popularity, its use has been clouded by controversy (2).

What is the Role of Creatine?

The vast majority of creatine is stored within the skeletal muscles of the body. Two thirds of this creatine exists as phosphorylated creatine – phosphocreatine – and the other third exists as free creatine. Phosphocreatine, being phosphate-bound, has to potential to provide energy via the transfer of phosphate to adenosine diphosphate (ADP) to produce adenosine triphosphate (ATP) within skeletal muscle cells (1,2). Hence, creatine is essential for ATP renewable and for muscle cells to continue to have a ready to use energy source. Under normal circumstances, enough ATP is present within skeletal muscle cells for 10 seconds of intense exercise (1). Some research has also suggested creatine aids with the reuptake of calcium into the sarcoplasmic reticulum which increases the rate at which actin and myosin can detach before they can subsequently reattach again (3).

Why is Creatine Used as a Sports Supplement?

Creatine is one of the world’s most popular sports supplements with its use becoming particularly prominent after the Olympic games in Barcelona in 1992 (1). No studies have shown creatine to be detrimental to sports performance (2) and it has even been described by the International Society of Sports Nutrition as the most effective nutritional supplement for improving high intensity exercise performance and lean body mass (2). Despite meat and fish being foods high in creatine, excessive quantities would need to be consumed to match what could be achieved by supplementation (2).

As described previously, phosphocreatine is required for renewal of ATP within muscle cells. Through supplementation, phosphocreatine levels can become elevated within muscle cells (1,2,4). As a result, it is proposed that the length of time fast twitch muscle fibres can rely on ATP as the primary energy source can be extended longer than the 10 second default leading to improved sports performance, particularly in sports requiring short intense bursts of energy. Furthermore, it has also been touted as a supplement which may increase lean muscle mass, strength and power (1–4).

More recent research has also suggested that creatine may also influence myogenic transcription factors. It has been demonstrated that levels of myostatin, a muscle growth inhibitor, were lower in those supplementing with creatine (3).

Whilst creatine can improve actual sports performance it can also improve sports training efficacy by allowing athletes to train at a higher level for longer (3). It has been shown that athletes using creatine had higher levels of muscle insulin-like growth factor 1 (IGF-1). This may be due to the more intense workouts these athletes were able to undertake due to creatine supplementation or, alternatively, due to the higher levels of creatine itself influencing IGF-1 production and muscle synthesis (3). Either way, it appears creatine has a part to play in this finding.

How is Creatine Used as a Sports Supplement?

Creatine can be taken orally in various forms, the most popular of which being creatine monohydrate (2,3). As yet, little evidence suggests that alternative formulations are any more effective, yet it is likely that some will be (2). There is no clear cut consensus about the dosage of creatine required to garnish the potential benefits of the supplement, however it is generally recommended that between 3 and 5g daily should confer the desired effects (1,2). Creatine monohydrate is the most common form of creatine, the most well researched (2) and cheapest to buy. Typically, it is suggested that it takes approximately one month of daily supplementation to reach saturation levels. Due to this rather long loading phase, it is commonly taken in higher doses close to 20-25g daily for three days to one week before moving down to a maintenance dose of 3-5g thereafter (1,2). Research has suggested that taking creatine with carbohydrate can improve its uptake into skeletal muscle due to the increased insulin release. By also incorporating protein, studies have shown improvements in muscle power and hypertrophy more than taking either protein or creatine alone (2).

Other Uses for Creatine

Creatine may not only be beneficial for sports performance, but for rehabilitating patients who need to gain muscle mass or as a potential therapeutic for Alzheimer’s disease, Parkinson’s diseases, muscular dystrophy, diabetes, lung disease, heart disease, high cholesterol and brain or spinal cord injury (2).

What to Expect from Creatine Supplementation?

It has been documented that creatine can quickly increase body mass. Immediately, this is thought to be due to the osmotic properties of the creatine molecules themselves. As more creatine is absorbed within muscle cells, more water is drawn osmotically into these cells too. This may make some individuals look more defined simply due to water retention within skeletal muscle (1), however increases in weight of up to 15% have been reported (2). Due to the movement of water into muscle tissue, it is possible that dehydration may occur without adapting fluid intake as appropriate (2). More long term, creatine has also shown muscle mass increases in combination with weight training when compared to control groups (1).

With regards to experienced improvements in power, one meta-analysis concluded that the average improvements from creatine supplementation combined with resistance training were 8-14% more than resistance training alone over a period of 12 weeks (5). However, not everyone taking creatine experiences the same benefits. It only makes sense that those with less creatine in their diet to begin with, such as vegans, have a higher likelihood of reaping the most benefits from supplementation (2,3).

Unfortunately, there has been little research to suggest that creatine supplementation is useful or beneficial in sports with a more aerobic preponderance. In a systematic review examining football players, it was concluded that supplementation with creatine resulted in no improvements in measured aerobic metrics, yet tests analysing anaerobic performance were enhanced. This is not particularly surprising since aerobic exercise is more dependent on triglyceride breakdown to provide energy rather than the phosphocreatine system (6).

The improvements in strength and increases in lean muscle mass linked with creatine supplementation are desirable for many but it should be remembered that most studies which came to such conclusions also incorporated resistance training (3).

Additionally, creatine supplementation may exhibit nootropic-like properties and improve mental capabilities such as focus and concentration (3). This may be why research on the use of creatine for neurological conditions such as Alzheimer’s disease is being pursued.

Is it Safe?

Current evidence suggests that creatine is safe to take for a short term period of up to 5 years (1,2) and there is no evidence that it is harmful over a longer period either (2,7).

Further Thoughts

Creatine uptake into muscle tissues is augmented by carbohydrates as they increase insulin levels (2). However, taking fairly large amounts of carbohydrate on a daily basis with creatine supplementation may not be ideal for those who are trying to lose weight or calorie restrict. Therefore, it may be ideal to improve insulin sensitivity if possible, which would provoke the same beneficial uptake response of creatine due to insulin, but at a lower threshold for insulin secretion. Increases in insulin sensitivity may be achieved through good diet, yet there may also be a role for additional supplements here.

There is still much research to be done on creatine and its roles within muscle cells such as increasing muscle growth factors and IGF-1 which may shed more light on why so many athletes find such benefit with the supplement.

Conclusion

Creatine is a safe and effective sports supplement that can increase an athlete’s power, strength, and lean muscle mass. It may allow athletes to train more effectively and perform to a higher level in competition. The most common form is creatine monohydrate which can be taken daily with doses ranging between 3-5g.

Sources

1. Butts J, Jacobs B, Silvis M. Creatine Use in Sports. Sports Health. 2018;10(1):31–4.

2. Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, et al. International Society of Sports Nutrition position stand: Safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14(1):1–18.

3. Cooper R, Naclerio F, Allgrove J, Jimenez A. Creatine supplementation with specific view to exercise/sports performance: An update. J Int Soc Sports Nutr [Internet]. 2012;9(1):1. Available from: http://www.jissn.com/content/9/1/33

4. Arciero PJ, Hannibal NS, Nindl BC, Gentile CL, Hamed J, Vukovich MD. Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flow. Metabolism. 2001;50(12):1429–34.

5. Rawson ES, Volek JS. Effects of Creatine Supplementation and Resistance Training on Muscle Strength and Weightlifting Performance. J Strength Cond Res. 2003;17(4):822–31.

6. Mielgo-Ayuso J, Calleja-Gonzalez J, Marqués-Jiménez D, Caballero-García A, Córdova A, Fernández-Lázaro D. Effects of creatine supplementation on athletic performance in soccer players: A systematic review and meta-analysis. Nutrients. 2019;11(4):1–17.

7. Jagim AR, Stecker RA, Harty PS, Erickson JL, Kerksick CM. Safety of Creatine Supplementation in Active Adolescents and Youth: A Brief Review. Front Nutr. 2018;5(November).