I just wanted to combine some posts of Chevy350TPI into one consilidated topic. Most of this information was found in the "New Workout, New Diet" thread but I figure it may not be found by the typical browser and it is very good information about creatine that should not be overlooked. Creatine The phosphagen system provides ATP. In the muscle, ATP is found near the myosin filament heads so it is readily available for the sliding filament theory cross-bridge step. Powerful and quick movement demands are taken care of by the phosphagen system. When you exercise, you do not deplete ATP in proportion to the requirement for that ATP - ATP hydrolysis produces ADP, inorganic phosphate and H+. These products react with creatine phosphate (CP) to re-form ATP. With a higher concentration of CP in the muscle (creatine supplementation), ATP can be provided more immediately versus having a lower concentration (Volek & Kraemer, 1996 and Volek, Kraemer, Bush, Boetes, Incledon, Clark, & Lynch, 1997). Fox (2006) states that the renewal of ATP is so critically important that an athlete may decide to supplement with creatine monohydrate or another form of the product. Athletes supplementing with creatine monohydrate have shown increased intramuscular phosphocreatine levels ... 15%-40%. Furthermore, Fox states that this increase in PCr can improve muscle mass and lead to an increase in strength and subsequently performance. In the near future we will see athletes who have been abusing (consuming 20g+ per day of monohydrate for extended periods of time, for example) come up in studies where this has ultimately led to liver and/or kidney damage. Moderation is key. 2-5g per day (well within the recommended dosage) should not be a problem for the vast majority of individuals. As always, we recommend visiting your physician or nutritionist to ensure you do not fit into a special population unable (or shouldn't) to supplement with the product. Earnest, Snell, Rodriguez, Almada, & Mitchell (1995), Greenhaff, et al. (1997), Kreider, et al. (1998), and Maganaris & Maughn (1998) all found that supplementing with creatine monohydrate significantly boosts performance and intracellular concentrations of creatine phosphate. With their articles being published in the Journal of Applied Physiology and The Medical Journal of Sports Exercise, for example, their studies are not taken lightly and have been subject to (failing) scrutiny. A typical individual will consume roughly a single gram of creatine per day. The body will synthesize creatine if roughly one gram is not ingested. Twenty grams per day has shown to increase total muscle creatine by approximately 20% (Birch, Nobel, & Greenhaff 1994). An increase of this magnitude can increase performance while exercising by 5% to 7% (Greenhaff, et al. 1997). Twenty grams of creatine is equivalent to roughly ten pounds of uncooked steak. Not all individuals will benefit from creatine. Some people are just non-responders. Of note should be that carbohydrate intake can dramatically increase muscle creatine uptake by more than 50% (Greenhaff & Casey 1997). Hultman and associates (1996), as well as Kreider and colleagues (1998), have demonstrated that the paralleled weight gain may or may not come from changes in hydration status. Regarding the negative health effects ... Studies have shown that 20g of creatine consumed for five consective days had zero effect on plasma creatine levels, blood pressure, renal function, or creatine kinase efficiency/activity. Furthermore, long-term creatine use has had no effect on a healthy individuals tubular reabsorption, glomerular filtration rate, and membrane permeability. Naturally, as aforementioned, problems can, and may very well would, arise should an individual with renal problems consume large amounts of monohydrate. Another interesting note regarding creatine is that if you do supplement with it, you should cut caffeine out of your diet. Caffeine has been shown to negate any ergogenic effects that creatine supplementation can give you. All in all, there are about 11 or 12 popular studies that have shown that supplementing with creatine monohydrate has no benefit. These studies do not give any reasons as to why this may be, nor have they been able to repeat the same study and achieve the same results. All Credit and Kudos to Chevy350TPI
