Competitive and recreational athletes use creatine monohydrate for its performance-enhancing, or ergogenic, properties. It's been shown in numerous studies to be beneficial in activities that are dependent on the anaerobic energy system, which includes such sports as powerlifting, sprinting, swimming and field events. Such sports typically involve high-intensity, short-duration movements with short rest breaks during training. The energy for them comes primarily from stored skeletal muscle ATP and ATP regenerated from phosphocreatine stores. Anaerobic glycolysis is another potential energy source, though its relatively slow rate of ATP production prevents it from contributing to short-duration activities; that is, those of less than 30 seconds.
Studies show that oral creatine supplementation increases total muscle creatine stores. Increases in creatine and phosphocreatine have been demonstrated by muscle biopsy, and those results correlate well with studies that measure anaerobic work performance.
To date, there have been no serious adverse effects associated with creatine supplementation; however, an undetermined percentage of creatine users has reported stomach upset, diarrhea and cramping, which suggests poor intestinal absorption. Anecdotal reports of muscle and tendon injuries appear to be related to inappropriate training and supervision during the initial period of creatine supplementation. Athletes may be susceptible to overtraining, or they may develop or exacerbate an imbalance between muscle groups during periods of accelerated strength and performance improvements.
Creatine monohydrate is typically found in powder form, and manufacturer directions recommend consuming it in eight to 16 ounces of water, juice or isotonic sports drink. They also recommend a loading phase at the beginning of a creatine cycle that consists of four to six five-gram servings a day for four to six days. A maintenance phase then follows, with the recommended dose being five to 20 grams a day. There are some deviations from the recommendations, but there's little evidence to support alternative modes of creatine use.
The majority of problems associated with creatine monohydrate occur during the loading phase. People complain of poor intestinal tolerance, as evidenced by cramps or diarrhea. Commonly, increased fluid consumption resolves the complaints, which are rarely mentioned during the maintenance phase.
There are numerous creatine monohydrate products around. One that has been shown to be beneficial is the combination of creatine and high-glycemic carbohydrates. Studies have shown that creatine uptake into muscle is enhanced in the presence of insulin with those products, which leads to increased muscle creatine stores over what subjects got with straight-creatine supplementation. There are other formula additions to creatine, but none have been shown to be of much benefit. One possible exception is inorganic phosphate salts, which may aid in maintaining the creatine-to-phosphocreatine ratio in the muscle cell.
The addition of carbohydrates has improved the ergogenic value of creatine; however, there's still a barrier keeping people from realizing the complete ergogenic value of creatine. That barrier is poor intestinal absorption. Creatine uptake is mediated by an active sodium dependent transporter, and there's extremely little passive absorption of creatine in the intestine due to the substance's poor solubility in water and the ionic nature in the intestinal environment. Compounding the problem is the supposed downregulation of the creatine transporter that occurs during supplementation. The absorption problem has been clearly demonstrated even during the relatively short loading period. That's consistent with the findings regarding other guanido compounds, such as taurine, in which the intestinal receptor is shown to downregulate following oral supplementation.
Overcoming that barrier should effect a significant improvement in creatine's ergogenic profile, both in the acute loading phase and the maintenance phase. Before the introduction of effervescent delivery, that just wasn't possible. The only recourse was to bypass the oral route in favor of intravenous administration. While there may be a place for that in therapeutic environments'for example, where there are patients with certain mitochondrial conditions'it's an unacceptable option for athletic enhancement or recreational use.
Effervescence occurs when weak acids and bases are combined to create a buffered solution at a stable pH. It typically involves the use of bicarbonate salts, which form carbon dioxide gas upon activation. The appearance of the carbon dioxide gas gives the bubbling, or fizzing, effect that you get with popular over-the-counter indigestion and allergy remedies.
Effervescence is a useful and applicable delivery device for creatine for many reasons. First, and possibly most important, is the buffering effect. Stabilizing the pH of the creatine-containing solution at the pI, or isoelectric point, promotes an electrically balanced, or neutral, creatine molecule known as a zwitterion. The net electrical charge of the zwitterion is zero. As creatine is a small molecule, it's now theoretically available for passive absorption'in addition to the active transport that has been shown to downregulate. That's important for two reasons. It provides an alternate and less restricted means of accessing the mesenteric venous system'the transport system can be quickly saturated even during the initial dose. Second, it allows for the continued absorption even during the maintenance phase.
An additional benefit of the buffering effect is the so-called dumping effect. Creatine is of maximum benefit at select times of the day; in the morning after the nighttime fast, for instance, or right after training. These windows of opportunity are short. Studies suggest that a 200-milliliter volume is held in the stomach for 40 minutes to one hour. If you drink more or a meal high in fat or protein is present, that period may extend for hours. The problem is, very little absorption takes place in the stomach by design.
The stomach's role is mostly to grind up and break down the food by acid digestion. Its musosal lining is nearly impermeable, which protects it from the destructive effect of the stomach acids.
The duodenum and the remainder of the small intestine are the sites of greatest absorption. The effervescent delivery of creatine causes a pH shift in the stomach, which the body senses as a signal to dump the stomach contents into the duodenum. Once the creatine passes into the duodenum, the greater surface area and absorptive function of the intestinal lining quickly absorb the creatine zwitterions. What's more, the creatine transporters are located in the jejunum and ileum, two other sections of the small intestine.
As the effervescently delivered creatine is almost completely absorbed, you don't have the stomach problems inherent in creatine use. Noneffervescently delivered creatine, particularly after transporter downregulation, is typically passed down the small intestine, drawing water into the lumen of the bowel in an attempt to dilute and dissolve the crystals. The creatine crystals act as an irritant and have a high osmotic pull. Unfortunately, the majority of water transfer takes place in the large intestine, which has very little absorptive capacity. That leaves the creatine in the colon, along with the attendant water load, and it's the water efflux and the presence of the colonic creatine that lead to diarrhea, cramps and dehydration. The greater absorption with effervescent delivery should remove that curse.
Bear in mind that creatine is designed to augment anaerobic work performance. That means a working muscle to near maximal exertion is highly dependent on the amount of available ATP during the period of exertion. Long-distance races and low-intensity-load exercise aren't significantly affected by creatine supplementation. Therefore, in terms of research it's more appropriate to measure the supplement's effects on repetitive sprints, isotonic, isometric or timed recovery resistance training than on marathon running or long-distance cycling.
One study that's been done in the exercise science labortory is the measure of anaerobic work performed on a cycle ergometer. That measures maximal energy output, which is dependent on ATP and the phosphocreatine shuttle. The study showed an increase in anaerobic work performance (AWP) of 10 percent following a creatine loading phase. Adding carbohydrates increased the AWP to 20 percent over the control group. That was the standard by which creatine products were gauged for the past three years'that is, until effervescent creatine with carbohydrate showed a significant improvement in AWP to 30 percent over the control subjects.
Marketing groups present the findings'and the figures'in confusing terms. Here are the basic facts shown by the research:
'Creatine provides a positive ergogenic effect when used and measured correctly.
'The addition of a high-glycemic carbohydrate enhances the muscle uptake of creatine.
'Thyroid hormone and vitamin E also seem to play a role in muscle uptake of creatine.
'Creatine's greatest drawbacks are its ionic nature and osmotic pull.
'Creatine's effects are further impeded by the use of active transport and the supposed downregulation of intestinal creatine receptors.
'Transit time may cause a variable delay in creatine delivery to the intestine for absorption.
'Effervescent delivery buffers creatine at its pI, which allows it to exist as a zwitterion.
'Effervescence also decreases transit time, providing a quicker and more reliable delivery to the intestine.
'Creatine as a zwitterion may be available for both active and passive transport, bypassing the reduced availability from receptor downgrading.
'Creatine causes a 10 percent increase over the AWP of control subjects.
'Creatine with carbohydrate causes a 20 percent increase over the AWP of control subjects; that is, it's twice as effective.
'Effervescently delivered creatine with carbohydrate causes a 30 percent increase over the AWP of control subjects; that is, it's three times, or 300 percent, as effective and 150 percent as effective as creatine and carbohydrate.
One further benefit of the effervescent creatine is that it is dose-metered in the individual packages, which means that each ingredient is added to each package individually to ensure that each serving contains the amount of each ingredient it's supposed to contain. That's in contrast to the large tubs of batched products, like the creatine-and-carbohydrate blends. The mixing process is imprecise, and settling occurs during both manufacturing and shipping. Creatine may be nearly nonexistent in one portion of the batch and over the stated amount in another. The effervescent system also requires a foil-sealed pack, which provides for a longer shelf life and fewer storage-related changes, and the individual serving packs make it more convenient to use.
Effervescent creatine represents a novel and effective use of a pharmaceutical delivery system that enhances the positive benefits of creatine and negates the adverse effects. Editor's note: Daniel Gwartney, M.D., is a clinical pathologist and a graduate of the University of Nebraska College of Medicine. He's been bodybuilding for more than 18 years. IM