Supplementing creatine for a short period of time (15 to 25g per day, 5 to 7 days) can increase total creatine by 15% to 30% (127 to 149mmol/kg dry weight muscle), and increase creatine phosphate storage by 10% to 40% ( 67～91mmol/kg dry weight muscle). The role of increased creatine and creatine phosphate reserves is to maintain ATP levels during high-intensity exercise and promote the resynthesis of creatine phosphate during intermittent periods of repeated high-intensity exercise. Therefore, short-term creatine supplementation can increase maximum work and/or maximum strength by 5% to 15%, increase muscle contraction capacity during maximum exertion by 5% to 15%, and increase single sprint capacity by 5% to 15%. In addition, long-term supplementation of creatine (15g to 25g per day for 5d to 7d, then 2g to 25g per day for 7d to 84d) can significantly increase strength, sprinting ability and lean body mass [9]. Another set of experiments by Richard et al. added creatine to a glucose-taurine-electrolyte drink for 28 days on humans engaged in activities (resistance training or flexibility training). The results were an increase in lean body mass and an increase in weightlifting and sprinting abilities. [10]. Grindstaff et al. gave 18 young professional swimmers in the training period creatine (21g/d) for 9 days, and maltodextrin for another 9 days as a control. They conducted 3 sets of 100m sprint swimming with 60-second intervals to test their ability. The result was that the first 100m experimental group was faster than the control group; the swimming time of the second 100m experimental group was significantly shortened; the cumulative time of three 100m swimming after taking creatine was shorter than that of the control group. The results show that 9 days of creatine supplementation during the training period can enhance the ability of repeated sprint swimming [11]. Kreider reviewed a large amount of literature and concluded that although there are individual studies that creatine supplementation has no strong effect, most studies indicate that creatine supplementation (20g per day, 5 to 7 days) increases sprinting ability by 1% to 5%; repeated sprinting The work done can be increased by 15%. He believes this powerful effect is related to the increased amount of creatine uptake by the muscles. In the review, he also mentioned that supplementing creatine for 1 to 2 months during the training period can further improve sprinting ability by 5% to 8%; strength can increase by 5% to 15%. Lean body mass increases by 1% to 3% [12].
The main function of creatine is to increase energy through skeletal muscles, cardiac muscle, smooth muscles, eyes, brain, and nervous system. Because these organs have to work and coordinate activities, increasing the level of creatine in the cells can enhance their ability to exercise. Excess creatine in the muscle does not increase the ATP concentration of the muscle at rest, but sufficient creatine in the muscle can ensure the resynthesis of ATP and creatine phosphate consumed during exercise, thereby maintaining the ATP concentration of the muscle during repeated maximum force sprint training. , which can minimize the production of local lactic acid in the muscles, allowing the human body to exercise at higher intensity for longer periods of time. This can help the human body strengthenStrength, increase functional capacity, enlarge muscles and prevent premature fatigue of the body [13, 14].
Research shows that creatine can increase the ability of muscle fibers to uptake protein. Actin and myosin are necessary for the contraction of all muscles. So when you increase these contractile proteins, you actually increase your muscles' ability to engage in physical activity, you'll do more work more of the time, and you'll be stronger [15].
Most studies believe that creatine supplementation mainly enhances exercise capacity during short-term, high-intensity, and repeated exercise. The American College of Sports Medicine states that creatine increases the pool of creatine phosphate to rapidly synthesize ATP. Taking creatine at a shock dose of 20-25g/d for 5-7 days, and then continuing to use it at a maintenance dose of 3-5g/d will improve the body's ability to maintain short-distance cycling, sprinting, swimming, high jumping and wrestling. Recent studies have also pointed out that in long-distance running, creatine can also enable athletes to train at a higher intensity than they are accustomed to without fatigue [16].