Since its first mass-produced in the early ’90s, creatine has vaulted to and stayed at the top of the supplement charts. While small numbers of elite athletes used creatine in the mid-’60s, these days everyone from pro athletes to weekend warriors and everyone in between seems to be on the creatine bandwagon. Unfortunately, the combination of creatine’s rapid rise in popularity and the public’s lack of knowledge has led to numerous myths and misunderstandings about its effectiveness and safety.
Creatine was first identified in 1838 by the French chemist Chevreul. In 1847, another scientist, Lieberg, concluded that the accumulation of creatine in the body is directly involved in supplying muscles with short-term energy. The investigation of creatine supplementation began in the early 1900s using creatine extracted from meats. But it wasn’t until the early 1960s that synthetic creatine production began. Former Eastern Bloc countries started using it for power sports, including weightlifting and track and field. Reports have circulated that several British Olympic athletes were supplementing with creatine before the 1992 Olympic games in Barcelona. The Olympic games in Atlanta were jokingly referred to as “The Creatine Games” because a number of athletes supplementing with creatine were awarded gold medals.
To date, dozens of highly credible scientific research articles have been published about creatine in various sports and medical journals. In addition, a number of papers have been presented at various meetings such as the National Strength and Conditioning Association’s Creatine Symposium. As of this publication, creatine is one of the most extensively studied nutritional sports supplements available to today’s athletes. It’s also one of the few supplements that does what the manufacturers claim and in a relatively safe manner.
ATP – The Energy Powerhouse
To fully understand creatine, we need to begin with adenosine triphosphate (ATP). ATP is the fuel used by the body for muscle contraction. From getting out of bed in the morning to those 300-pound bench presses later in the day, ATP is responsible for all the muscle action we take for granted. But our muscles have limited stores of ATP available. Therefore our bodies must continually synthesize it.
The Big Three
The body utilizes three different mechanisms to manufacture ATP:
- Creatine kinase (anaerobic)
- Glycolysis (anaerobic)
- Oxidative phosphorylation (aerobic)
The initial and most effective method is creatine kinase, which utilizes a non-oxygen dependent process that is responsible for all maximal or near-maximal muscle contractions. Creatine kinase rapidly converts the initial stores of ATP to energy, and is responsible for any highintensity, short-duration activity such as sprinting, jumping or lifting weights. As ATP is used, it loses a phosphate molecule and becomes adenosine diphosphate (ADP), which is useless until it can be converted back into ATP. This is where creatine comes in. Creatine is initially stored in the muscle as creatine phosphate. As creatine phosphate, it can “donate” its phosphate group to ADP, thus converting it back into ATP, which is then available as a fuel source. This process is continuously occurring, with ADP converting to ATP, and ATP breaking down into ADP + a single phosphate group.
Glycolysis, the second mechanism for producing ATP, is less efficient than the creatine kinase pathway. During glycolysis, a glucose molecule is broken down into two pyruvic acid molecules, yielding two ATP molecules in the process. Glycolysis, however, requires more steps than creatine kinase, and thus results in a slower yield of ATP. Even though glycolysis provides the energy to perform intense exercise, it has two important consequences. First, it 286consumes large amounts of nutrient fuel to yield the ATP molecules. This, in turn, rapidly depletes the muscle’s glycogen stores. Second, the end product of anaerobic glycolysis is lactic acid. Lactic acid is one of the causes of that soreness you feel during and after an intense workout. The lactic acid buildup is also one of the reasons you fatigue after 60 to 90 minutes of exercise.
The third mechanism for ATP production is called oxidative phosphorylation. This is an aerobic process fueled by glucose or fatty acids, depending on the duration and intensity of the activity. Of the three, this is the slowest process for producing ATP because of the high number of steps involved, and because of its dependency on a constant supply of oxygen. Oxidative phosphorylation sometimes works in conjunction with glycolysis. The type and duration of the exercise dictates which of these energy processes will be used in greater amounts.
Don’t let all this biochemistry frighten you. What’s important to remember is that in the short term, anaerobic exercise is enhanced with creatine supplementation, which in turn provides the increased supply of creatine phosphate molecules needed to convert ADP back into ATP. Also, by increasing the body’s store of creatine phosphate, creatine supplementation prolongs the creatine kinase process. This delays the need for the oxidative phosphorylation and glycolysis pathways, which, as we saw earlier, are slower and less efficient. In the research to date, creatine supplementation has not been shown to enhance aerobic activities.
Despite what some supplement manufacturers would have you believe, creatine is naturally synthesized in the liver, pancreas and kidneys from the precursor amino acids: arginine, glycine and methionone. Dietary creatine is also available in meats and fish, but creatine content depletes rapidly when foods are cooked. One pound of raw, red meat offers approximately 2 grams of creatine.
Most people, however, store only about 60 to 80 percent of their potential creatine levels. Supplementing with creatine enables individuals to elevate their creatine stores an average of 30 percent. This additional creatine gives the body the necessary ingredients to reproduce more ATP during the creatine kinase process and to ultimately generate more work. At its simplest: more work equals more muscle stimulation and more muscle stimulation equals greater muscle size. Creatine does for the bodybuilder what carbohydrate loading does for the long-distance runner: it provides more energy-producing materials, which enables more work to be generated.
The key to proper creatine usage is to find the lowest dosage that supplies the maximum benefit. Currently no optimal dosage amount has been determined. However, there is a huge volume of anecdotal evidence. One of the most popular ways to go about creatine taking is to complete a loading phase, which consists of taking approximately 5 grams of creatine, three to four times a day, for a period of five to seven days. This is followed by a maintenance phase, which consists of taking 2 to 5 grams per day thereafter. Some suggest that the loading phase is unnecessary, wasteful and simply a ply by manufacturers to get bodybuilders to buy more of their product. They state that an individual who starts supplementing with only the maintenance phase (2 to 5 grams/day) will have the same muscle saturation in three weeks as the individual who loads.
Creatine absorption is enhanced when combined with a substance such as dextrose, which increases insulin levels. You can take creatine with juice or any other high simple-sugar beverage. Ingesting creatine with a meal will provide the same effect, as food causes increased insulin production. Some studies have also shown that worked muscles will absorb more creatine than non-worked muscles. It follows that taking creatine directly after a workout may make some sense, although evidence to support this is not conclusive. Many bodybuilders take creatine with their pre-workout meal and then again after their workout with fruit juice or another high-sugar drink.
Over the last couple of years, creatine has been getting a lot of bad press. The media maligning of this popular sports supplement has been a surprise to many athletes and coaches, because it is known with relative certainty that creatine can indeed help improve muscular strength and size in a variety of different athletes (including football players, bodybuilders, weightlifters, swimmers, and cyclists).
The heart of the bad press concerns creatine’s alleged side effects, including muscle, tendon and ligament strains. In theory, creatine can improve the explosive energy production of muscle cells without actually fortifying the mechanical strength of a muscle, its attached tendons or the ligaments holding together the joints across which muscles and tendons act. As a result, the theory goes, the unusually powerful contractions produced in creatine-loaded muscles might literally tear the muscle cells and/or their associated connective tissues.
Anecdotally, athletes using creatine do appear to have increased incidences of strain. However, I must point out that no carefully controlled scientific study has linked creatine supplementation with a heightened risk of muscle or connective-tissue damage. In addition, linking two events together – increases in creatine loading with apparent increases in injuries – does not mean that one causes the other. Perhaps the athletes who are likely to use creatine are also more likely to push themselves to the extreme, risking injury.
Some reported deaths of wrestlers brought creatine a heap of bad press in the late 1990s. The fact that the wrestlers were taking diuretics and engaging in other risky weight-loss practices was quietly ignored by the media. Instead, the press focused exclusively on creatine, making it the scapegoat.
Most of the side effects associated with creatine use, such as stomach cramping and diarrhea are dosage related. Most users who experience these side effects are taking 10 grams or more all at once, instead of taking smaller amounts spread throughout the day, as recommended. No substantiated reports of serious side effects from creatine have occurred despite over 12 years of mainstream usage. Whether long-term side effects from this natural compound occur years down the road remains to be seen.