What is creatine?
Creatine monohydrate is one of the most popular and extensively studied supplements used by athletes due to its ability to increase intramuscular creatine concentrations, improve exercise performance and enhance adaptations to training (Kreider et al., 2017). 95% of the human body’s creatine stores are found within muscle while the remaining 5% exists in the liver, kidney, and testes (Persky and Brazeau, 2001). Creatine is found in protein sources such as meat, poultry, and fish with the average individual consuming ~1-2g of creatine per day from their diet. However, this amount of dietary creatine only saturates the muscles creatine stores by 60-80%. Therefore, creatine supplementation is needed to further saturate creatine stores with the potential to increase intramuscular creatine stores by 20-40% (Andres et al., 2017).
Why should you supplement with creatine?
Adenosine triphosphate (ATP) is the body’s energy currency for processes such as muscle contraction. ATP is not stored in large amounts within the body. Therefore, once exercise begins and your muscles begin repeatedly contracting, the demand for ATP production increases. When the energy demand of performance is high (e.g. when high intensity work is required), creatine (specifically phosphocreatine) is needed to produce ATP at high rates (Butts et al., 2018). Increasing intramuscular creatine concentrations by means of supplementation facilitates faster resynthesis and production of ATP, ultimately delaying fatigue.
In simpler terms, the main benefit of creatine supplementation improves short or repeated high-intensity performance efforts by enhancing energy production and delaying fatigue. This means a higher amount of high quality of work can be performed during training/competition leading to an increased potential for greater training adaptations. This is beneficial for athletes participating in team sports where repeated sprints are often required. Creatine supplementation also has ergogenic benefits in events lasting <30 seconds, for example, track athletes (60 – 200m sprint), swimming (50m sprint), weightlifting and track cycling (Kreider et al., 2017).
Aside from improving the mechanism of high intensity energy production, there are other reported benefits of creatine supplementation. Creatine has also been shown to increase lean body mass when combined with training, making this a suitable supplement for ALL athletes. By improving an individual’s ability to train harder at high intensities, athletes will be better able to promote greater training adaptations. Such adaptations include muscular strength and hypertrophy due to an increase in the expression of enzymes responsible for muscle contraction (Budford et al., 2007). Long term studies by Kirksey et al., (1999) and Noonan et al., (1998) have demonstrated that those who supplement with creatine elicit greater gains in lean mass by ~50% when compared to placebo groups.
One of the main issues experienced by athletes during periods of inactivity resulting from injury is a loss in muscle mass. This is another instance where creatine comes into action. Hespel et al., (2001) demonstrated that the recovery of muscle mass following a period of immobilisation was enhanced when creatine was supplemented during rehabilitation to a greater extent than those who were given a placebo. By enhancing muscle mass recovery, the subsequent strength gains that can be made during a rehabilitation programme are increased. There is also some research which suggests creatine supplementation can be used to lessen muscle atrophy during periods of immobilization. However, this effect has not yet been fully explored.
How much creatine should you take?
Following the advice given by the International Olympic Committee, typical creatine supplementation protocols begin with a ‘loading phase’. The loading phase consists of consuming 20g of creatine per day in 4 equal doses e.g. 5g at breakfast, lunch, dinner, and pre-bed. There is evidence to suggest that consuming creatine with a mixed protein and carbohydrate meal can enhance the bioavailability of creatine. Therefore, taking creatine at meal times may be the most optimal approach. A loading protocol should be followed for 5-7 days to saturate creatine stores. Following this, a maintenance dose of 3-5g per day is needed to maintain creatine stores (Maughan et al., 2018). If supplementation is stopped it can take between 4-6 weeks for the muscles creatine stores to return to baseline (Kreider et al., 2017)
Will everyone benefit to the same extent from creatine supplementation?
The short answer is no. How an athlete responds to creatine supplementation will depend on how saturated their creatine stores are to begin with. Some of the factors that influence intramuscular creatine stores are as follows:
- Type of diet: It has been shown that individuals who follow a vegetarian diet have lower intramuscular creatine concentrations due to the absence of meat/poultry produce in their diet. Therefore, these individuals will benefit to a greater extent from creatine supplementation than someone following a ‘normal’ diet (Kreider et al., 2017).
- Training status: Athletes who train at a high level typically have higher intramuscular creatine stores than the average individual. Therefore, the degree of improvement seen will be higher in untrained vs trained individuals (Cooper et al., 2012). However, it is important to remember that marginal gains in performance can be the difference between winning and losing when elite athletes are considered.
Are there any side effects of creatine supplementation?
There are no known health implications when supplementing with creatine long term (up to 4 years). However, acute symptoms such as gut discomfort may occur during the initial stages of supplementation. By splitting the loading dose into 4 smaller doses this should aid in minimising such symptoms. Athletes may also experience bloating as a result of water retention. This could lead to acute weight gain of 1-2kg. This is an important consideration for athletes who take part in sports where performance is sensitive to body mass. For example, endurance events, combat sports where athletes are required to fit into specific weight categories, and events where body mass must be moved against gravity (e.g. high jump) (Maughan et al., 2018).
This does not mean these athletes should ignore the use of creatine supplementation as it still has the potential to induce performance gains. However, the athletic populations mentioned may want to follow a supplementation protocol that is periodised in line with competition. For example, stop the use of creatine in the weeks leading up to weigh-ins/important competitions. Water retention may also be minimised by avoiding the initial loading phase. If an athlete chooses to do so they could maintain a consistent dose of 5g per day at the onset of supplementation. However, this method would lead to a more gradual increase in creatine stores and have less of a beneficial effect on performance until creatine stores are fully saturated. This may take several weeks vs 5-7 days when a loading phase is implemented (Maughan et al., 2018).