Only studies that involved adults and provided separate prevalence data for men and women were included in the elite versus non-elite meta-analyses. ATP can be used by muscle cells very quickly, but there is only an extremely limited supply -- usually only enough for a few seconds of high intensity work.
Quantitative prevalence data could be contained within the text of the article, in tabular form, or presented in graphs.
Remember, it's your body! Where there were at least two investigations, meta-analysis was performed to obtain summary pooled prevalence estimates SPEs on 1 DS use prevalence by sport and sex, 2 DS use prevalence by elite versus non-elite athletic status, and 3 specific DS prevalence for all athletic groups combined.
The body can recharge creatine back to phosphocreatine, but this takes time approximately 30 - 60 seconds. The fastest method is to move the phosphate group off of phosphocreatine and onto ADP. Creatine supplementation, in the dosages commonly used, results in urinary concentrations that are 90 times greater than normal.
If an endurance athlete needs to dip into the anaerobic range, for a sprint or hill climb, the needed extra energy primarily comes from anaerobic glycolysis of glucose yielding lactic acid, and that wonderful muscular "burning" sensation.
Recently, a baseball player for the Houston Astros was determined to have suffered from dehydration, kidney stones, and transient kidney damage as the result of creatine supplementation. Such was the case in the late 's when an epidemic of cases of eosinophilia-myalgia syndrome, including over 30 deaths, were blamed on a contaminant present in L-tryptophan 9an amino acid supplement widely taken as a sleep aid.
Key Points When dietary supplement use was compiled by sport, elite versus non-elite athletic status, and supplement type there was high variability in use prevalence among studies.
Too often the latest fad turns out to do nothing or is harmful. In fact one study, which measured running performance over a 6 km course, found slower times in the creatine supplemented group 8.
Among student-athletes, self-reported use of social drugs such as tobacco, marijuana and cocaine are much lower than the rates reported in other national studies of college students e. No published investigation has been conducted on creatine to determine what impurities might be present in creatine supplements, and what their long term effect might be.
Review by Mark A. Thus, "slow twitch" athletes cannot generate the speed and force of their "fast twitch" cousins, but they can do their thing for a long time. Alcohol excluded, student-athletes are much less likely to engage in social drug use than other college students.
People with kidney or liver disease should not take creatine. I2 indicated the percent of heterogeneity among studies, with smaller values denoting more homogeneity and larger values less homogeneity. Why do people take creatine? Large amounts of carbohydrates may increase the effects of creatine.
Data presented in graphic form were estimated. Jenkins, MD If you haven't yet heard of creatine supplementation you soon will. The exogenous intake of creatine appears to exert negative feedback on the endogenous production of creatine i. Homogeneity of the pooled prevalence estimates was assessed using the Q- and the I2-statistics [ 29 ].
Conclusion It was difficult to generalize regarding DS use by athletes because of the lack of homogeneity among studies.As expected, the studies which looked at endurance exercise failed to show any benefit of creatine compared to placebo.
In fact one study, which measured running performance over a 6 km course, found slower times in the creatine supplemented group (8). This effect is possibly related to the weight gain (mean 1 kg) associated with creatine use.
Oct 06, · Nonetheless, the tables in the present study provide a comprehensive summary of available data on the use of dietary supplements by athletes. When comparisons were made between elite and non-elite athletes, the SPEs suggested that elite athletes tended to use dietary supplements to a greater extent than the non-elite athletes.
Many athletes prefer to use the powder form of the substance, which can be mixed in with fluids and is quickly directed into the bloodstream.
Creatine is best absorbed when taken with carbohydrates. The best time to take creatine is directly after a workout - this is when your muscles are most receptive to absorbing creatine from the blood.
As such, if an athlete suffers an injury, creatine supplementation might be a worthwhile intervention. The dose used in many studies was 20g per day, although if the athlete is already consuming creatine such a loading phase may not be required. As such, creatine is now present in many pre- and post-exercise ready-made mixes, which athletes might wish to consider.
The combination of creatine and caffeine pre-competition (or even during competition, if the competitive bout is prolonged) may enhance the decision-making ability, and offset feelings of fatigue.
Creatine phosphate helps make a substance called adenosine triphosphate (ATP).
ATP provides the energy for muscle contractions. The body produces some of the creatine it uses.Download