Creatine is an amino acid. It is naturally occurring i.e. it is made in the body in the kidney, liver and pancreas. Creatine is obtained from foods such as meat and fish. In the body, creatine is converted to creatine phosphate and taken to reserves in the muscle. In the case of extreme intensity, short intervals of exercising such as weight lifting and sprinting it is used as an energy source. The storage form phosphocreatine is converted to the body's energy currency, ATP and used. The fact that it has this use has meant that athletes and body builders have use for it. Reported upsides to its use are that it increases lean muscle mass and enhances performance of high intensity short duration sport athletes. This paper will review three studies done with creatine testing its ergogenic properties.
The studies conducted on creatine have centered majorly on its effectiveness as a supplement. There are various forms of creatine in the market today. These include creatine phosphate, creatine monohydrate and pure creatine. It has been billed as a means to improve muscle size and strength, promote muscle endurance and facilitate quick muscle recovery. These claims have been tried and tested in clinical trials involving athletes and sedentary persons that are then subjected to high intensity workouts.
The first study to be reviewed was carried out by Barber et al.( 2013) of the University of San Luis Obispo in California. The study was meant to test the outcome of a combination of sodium bicarbonate and creatine regimen on exercising athletes’ physiology. The purpose of sodium bicarbonate was to increase blood pH and decrease the lactic acid concentration.
The test participants were trained men who filled out a Physical Activity Readiness Questionnaire and an exercise test on a bicycle ergometer with increasing difficulty. The total sample size was 13 males. They were tested to meet at least three of the standards intended for the study. These were respiratory exchange ratio of 1.15, a heart rate more or less within 5 beats of the expected beat for their age, VO2> 55ml kg-1min-1 or the subject stopped the exercise voluntarily. These tests were done to ensure that the criteria for athleticism were met. The subjects were between the ages of 18 and 30 and were subjected to aerobic exercises and high intensity training at five and two hours per week.
The limitations of this study was that it was impossible to tell the progression of change of the blood pH and the sodium bicarbonate in the course of the repetitive sprinting as the blood samples were obtained after the six rounds of sprinting. The condition of sodium bicarbonate alone was not tested and therefore the effects of the same cannot be determined exclusively. The third limitation was the high levels of variability in the parameters measured. Lastly, despite the observation of a 7% rise in maximum power in Cr compared to Pl, no changes were noted in peak and average power as well as exhaustion indicators. The study was not sufficiently long to observe the alterations in these parameters.
The results were recorded in terms of the parameters measured. Maximum power output was relatively elevated in creatine + sodium bicarbonate regimens than the placebo and creatine alone. Blood analyses were carried out and they showed that the creatine + sodium bicarbonate regimen raised the blood bicarbonate levels pre-exercise but there was no significant difference with the other groups after the exercise. Subjectively, the feeling of fatigue and gastrointestinal distress was the same for all the groups. The results were analyzed using SAS statistical software.
The second study under review was carried out by Galvan et al.( 2015). The rationale of the experiment was to test exercise effectiveness of creatine monohydrate against the claims that newer forms being introduced have greater efficiency. Creatine monohydrate is the most studied form of creatine tested for its effectiveness and efficacy.
The study drew in 48 participants. These were recreationally active males. Additionally, 21 sedentary women were included in the study. The ages of the participants ranged from 18-24 years. A standard medical exam was done by a research Registered Nurse to clear the participants for the study.
The samples used in the study were muscle biopsies taken before and after the testing protocols were done. 12-hour fasting blood sample, and Wingate anaerobic sprint test and body composition examination. The study lasted for a period of six weeks. One way ANOVA was used to test the data.
The test criteria used was ingestion of creatine monohydrate, placebo, and creatine nitrate in two different doses. The results showed that all treated participants increased their bench press repetitions after 28 days of supplementation. Total work was greatest in the higher dose of creatine Nitrate. Average velocity during the bench press was also greater in the creatine nitrate. Inferentially, the results suggest that there is a difference in consumption of the different variations of creatine available during training that is greater than the placebo.
It was also found that the type of ergogenic aid may lead to more training adaptation if combined with the appropriate resistance training exercise. Essentially, the muscle biopsy showed that the Creatine nitrate increases the muscular endurance, muscle mass and lean and fat free mass. The limitation in this study is the fact there was no double strength creatine monohydrate administered to enable comparison to the double strength dose of creatine nitrate.
The third test under review was done by Wang et al., (2016). It examines the consequences of creatine supplements on the maximal individual Post-activation potential (PAP) time and on explosive performance. The PAP time is a process that may induce increase in muscle ass however, it is dependent on the individuals muscle fatigue. The design of the study meant that the subjects performed thirty back squats for one repetition and complex exercise regimens to determine the optimal PAP time. The complex training regimens involved biomechanically similar plyometric activity following bouts of heavy resistance training.
The subjects of the study were male university athletes. They were drawn from baseball, basketball teams. Ten were taken from each team to make up a sample size of thirty. They were asked to maintain their diet and training programs for the duration of the study.
A high dose of Creatine (Cr) or placebo (pla) was administered for six days after which a low dose of the same was sustained to the conclusion of the study. All the participants visited the laboratory for anthropometric measurements. This included the percentage of body fat, the body height and mass (kg). Statistical analyses were performed on the data obtained using SPSS software.
The results of the study showed that after six days of supplementation the one Repetition maximum was higher in subjects with cr supplementation. There was no noteworthy change in height. The PAP time was significantly faster in the cr group than the placebo. The study showed that Cr supplementation augmented the maximal power of the lower limbs and reduced the detrimental outcomes caused by fatigue on PAP time. An overall improvement in explosive performance was not observed. The limitation of the study was mainly the duration. It was too short to register changes in anthropometric measurements.
The best sources of dietary creatine have been found to be game meat. These include venison, bison, buffalo and elk. These also have the added benefit of being lean with less calories and saturated fats. The fact that these meats are difficult to find is the barrier to using their rich creatine stores. The next best dietary source is free-range meats such as Cornish chicken, veal, lamb, turkey breast among others. The last source is wild-caught fish that tend to have a higher creatine per weight ration than farm-raised fish.
Vegetarians are restricted to finding dietary sources that are rich in arginine, glycine and methionine in order to enable their bodies to manufacture creatine naturally. These foods include peanuts and coconuts for arginine, spinach and sesame seeds for glycine and Brazil nuts and sunflower seeds for methionine. This however does not equate to the non-vegetarian dietary sources (Jackson, 2014).
The recommended Dietary Allowance for creatine has yet to be established. However, from conducted studies a loading dose of 20g/day for up to one week followed by a 3-5g/day or 2-5g/day as a maintenance dose henceforth. Toxicological information suggests that a dose of 2-5 grams per day of creatine supplements is sufficient for maximal creatine levels (HPRC). This is equivalent to three to six ounces of wild-caught fish a day.
Alternatively, there is approximately 5 grams of creatine for every 1.13kgs of meat. Beef and chicken lose about 5 percent of their totality of creatine once cooked unless boiled or stewed. Up to 30% may be lost if the meat is braised for a long time. 1.13kgs of meat are equivalent to 13 servings and may therefore be an impractical option for athletes attempting to maximize on their dietary creatine consumption (Busch, 2015).
The price per serving of creatine averages at a dollar a day (Bodybuilding.com, 2016). In order to ensure daily consumption of the optimum 5g/day, the athlete will have to fork out 7 dollars every week to acquire the creatine supplement. This is sustainable. However in order to determine the feasibility of the creatine regimen, the athlete has to measure the pros and cons of the supplement.
Essentially, the effectiveness of creatine in improving lean muscle mass, reducing the effects of fatigue on PAP time and permitting the athlete to undertake high intensity short duration workouts effectively cannot be disputed. However, the endurance of the athlete has not been shown to be positively affected by the same.
In the same light, it is clear that there are side effects to the creatine regimen. These side effects include the development of dependence by the body on the supplementary creatine and therefore shutting down the inherent production mechanisms. Additionally, the athlete may suffer gastrointestinal distress and kidney toxicity. Because the side effects are rare and the benefits have been shown to be universal, the creatine supplementation is viable. However, the effects of creatine have only been proven when combined with high intensity exercise. The intake of large amounts of creatine by oral route has been suspected to cause problems in the heart, liver and kidney.
Based on the studies above, creatine supplement is effective. It is however most appropriately used by athletes requiring short bursts of strength to complete high intensity exercises such as weight lifting and sprinting. Athletes in team sports also stand to benefit from the effects of creatine. The fact that creatine has been shown to build lean muscle mass means it is also useful for the body builders.
In conclusion, creatine is a portent supplement for athletes. Its physiological function as a storage medium for energy is reason enough for it to be considered as such. For its ability to increase muscle mass and endurance as well as mediate the effects of muscle fatigue it is a supplement of choice for weight lifters and sprinters. Creatine is more efficient in combination with sodium bicarbonate. The optimal form of creatine to be used was found to be creatine nitrate as this was found to provide greater variance from pure creatine.
Barber, J. J., McDermott, A. Y., McCaughey, K. J., Olmstead, J. D., & Hagobian, T. A. (2013). Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men. The Journal of Strength & Conditioning Research, 27(1), 252-258.
Bodybuilding.com (2016). Creatine. Retrieved from http://www.bodybuilding.com/store/creatine.html
Busch, S..( 2015). the Amount of Creatine in Meat. Retrieved from http://www.livestrong.com/article/524782-the-amount-of-creatine-in-meat/
Galvan, E., O'Connor, A., Goodenough, Y. C., Dalton, R., Levers, K., Barringer, N., & Murano, P. S. (2015). Effects of 28 days of two-creatine nitrate based dietary supplements on bench press power in recreationally active males. Journal of the International Society of Sports Nutrition,12(Suppl 1), P17.
HPRC. HPRC Dietary Supplement Classification System: Creatine. Retrieved from http://hprc- online.org/dietary-supplements/files/creatine
Jackson, B..( 2014 July). The best food sources of muscle-building creatine. Retrieved from http://www.naturalnews.com/045961_creatine_vegan_diet_muscle_mass.html
Wang, C. C., Yang, M. T., Lu, K. H., & Chan, K. H. (2016). The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Post-activation Potentiation Time. Nutrients, 8(3), 143.