Creatine use back in the 90's was popular because it actually did what was claimed on the container (unlike many other supplements). It definitely changed how sports nutrition was viewed.
Creatine is a natural compound in our body produced from amino acids. It is also found in red meat and some fish. In our muscles, it is called phosphocreatine (or free creatine) where it is necessary for enabling movement and exercise. Phosphocreatine is responsible for quickly restoring ATP levels in muscles, which functions as the 'energy currency' for cells.
ATP is broken down (or used) when our muscles contract during exercise and other activities. Phosphocreatine provides a qiuck pool of energy to allow quick restoration of ATP, which is fuel especially for high intensity exercise. Since creatine exist only in small amounts in the body, it is enough to fuel about 10 seconds of intense effort or all out sprint. Hence this is the 'free creatine' energy we all have in our bodies when needed for that 10 seconds worth of intense exercise.
Note that the body can also produce ATP from carbohydrates and fat, but it is a relatively slow process.
How creatine works is that it is able to produce strength gains because it enhances the short term, high intensity energy pathway in muscles called the phospho-creatine (PC) system.
If the PC system is enhanced, it allows our muscle fibers to contract vigorously for longer periods allowing more intense loading and fatigue for the muscles. After the muscles break down, it produces greater repair and growth stimulus with adequate rest and nutrition This ultimately results in greater strength gains.
Taking creatine supplements can increase creatine stores in the body by up to 30 percent. Many types of creatine are available, the cheapest and most researched being creatine monohydrate. Bear in mind that the pricier creatine hydrochloride and ethyl ester have not been proven to be superior.
Many people who take creatine start with a loading phase of 20-30 grams per day (for up to 7 days) to saturate stores quickly, leading to a rapid increase in muscle stores of creatine. Subsequently, they take 3-5 grams daily to maintain levels.
Those who choose not to load will consume 3-5 grams daily. Research shows this is just as effective and it will take up to a month to maximise stores this way before it has an effect.
A known side effect of consuming creatine is weight gain since creatine causes water retention in your muscles. This weight gain varies between 1-3 kg and not everyone who takes creatine experiences it. It can also cause mild stomach discomfort when large doses are taken. Long term supplementation with high doses have been investigated and shown to be safe in healthy subjects (Kreider et al, 2017).
Creatine supplementation is extremely popular with sprinters, strength and power athletes, especially when their events last for less than 30 seconds. It increases muscle mass and strength during weight training as well as improving performance during competition.
Since body weight is not as important in sprints, weight and power lifting, athletes from these sports can benefit as increases in performance more than compensates for the increase in body weight.
Those who participate in sports like soccer, basketball or hockey when intermittent short bursts of high intensity sprints and jumps are required will benefit with creatine supplementation. Specific tests where power output and speed are improved have been shown in athletes in such sports (Ramirez- Campillo et al, 2016).
What about endurance sports? In ultra events, the need for high intensity surges or bursts are less frequent, so as exercise duration increases, benefits of creatine reduces. Research on endurance sports are mixed though most show no benefit. An increase in body weight from consuming creatine may increase energy requirements and require greater power output.
I was asked why I took creatine supplements since research does not show much support when I used to race triathlons. I mainly raced the Olympic distance (1.5km swim, 40km bike, 10 km run) triathlons where fellow competitiors may surge on the climbs during the bike or run section to breakaway or get a gap. As such, we do need to respond to such high intensity surges otherwise the race may be over if you get dropped.
This was the main reason I thought taking creatine may help, since I needed to be able to sprint intermittently during my event, especially up slopes or near the end of a race. Studies that investigate cycling using stationary bikes where slight increases in body weight may not affect performances show benefits from taking creatine. This may occur in similar scenarios that I mentioned in a climb during a race or a sprint finish where there is a need for higher power output or speed (Murphy et al, 2005).
At these times, phosphocreatine contribute heaps to energy production, so an increase in creatine stores may be helpful. Bear in mind that the increase in body weight that sometime accompanies creatine supplementation is sufficient to cancel out the benefits. Especially in a hilly or longer race.
Utimately I stopped taking creatine supplements after 3 months because I did put on 1-2 kg of body weight. In addition I was not sure if it helped my ability to sprint and close gaps. I naturally have a good amount of Type IIa and IIb fast twitch muscle fibers already so the weight gain was not justified.
If you, like my patients, have heard good results about creatine and want to try it, bear in mind the scenarios that I mentioned.
References
Kreider B, Kalman DS, Antonio J (2017). International Society Of Sports Nutrition Position Stand: Safety And Efficacy Of Creatine Supplementation In Exercise, Sport, And Medicine. J Int Soc Sp Nutr. 14:18. DOI: 10.1186/s12970-017-0173-z
Murphy AJ, Watsford ML, Coutts AJ et al (2005). Effects Of Creatine Supplementation On Aerobic Power And Cardiovascular Structure And Function. J Sci Med Sp. 8(3): 305-313. DOI: 10.1016/s1440-2440(05)80041-6.
Ramirez-Campillo R, Gonzalez-Jurado R, Martinez C et al (2016). Effects Of Plyometric Training And Creatine Supplementation On Maximal-intensity Exercise And Endurance In Female Soccer Players. J Sp Med Sci. 19(8): 682-687. DOI: 10.1016/j.jsams.2015.005. DOI: 10.1016/j.jsams.2015.10.005
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