Feeling tired and thin?

Maintaining body weight and muscle mass are important goals for any person and are a constant source of discussion on "The Oprah Show" and "Rosie." For the HIV-infected person, achieving these goals is especially difficult, as a result of the activity of the virus itself and of many of the antiviral medications prescribed to control viral activity. The loss of weight and muscle mass from virus-related wasting and drug-related metabolic disruptions can result in decreased energy levels, a loss of quality of life, and more rapid progression to AIDS-related illnesses.

Creatine, a nutrient that is produced naturally in our bodies, is believed to aid significantly in the production of lean muscle mass when used with a regular exercise program that includes weight lifting. Studies of creatine have also identified many other health benefits that are of special interest to people infected with the AIDS virus and taking antiviral medications.

Take it from the top

Creatine works within the skeletal muscles used for muscle contraction. Creatine is found in the muscle fibers in two forms: free, chemically-unbound creatine and as creatine phosphate. The latter form of creatine, creatine phosphate, is two-thirds of the creatine supply and is the form that can be replaced through nutritional supplements. When muscles contract (as during weight training), the substance in the body that initially promotes this contraction, called adenosine triphosphate (ATP), is quickly depleted, usually within 10 seconds of the contraction. To fuel additional muscle contractions, creatine phosphate, found within the muscle fibers, releases its phosphate molecules to assist in the creation of additional ATP. This process, called "ATP synthesis," is necessary to create the amounts of ATP needed for sustained muscle movements. ATP synthesis requires a good supply of creatine to work properly.

Although creatine is found in most meats and fish in moderate levels, the average daily amount provided by the foods we eat is only about 1 gram. The average couch potato requires about 2 grams of creatine per day, and this daily requirement is significantly higher for active people. For a person with HIV whose metabolic rate is burning calories at 10 to 35 percent higher than the norm, the daily requirement of creatine is even greater. Relying on diet alone, it would be difficult to replace all of the creatine that is used by the body each day. Additionally, many of the foods high in creatine are also high in cholesterol and transfatty acids, presenting additional health risks from high consumption of these foods. One option for supplying adequate levels of creatine to the system is to supplement your diet with the fat-free, cholesterol-free supplement known as creatine monohydrate.

How do we know it works?

Creatine monohydrate is not a new discovery, and has been researched in a variety of settings for over a century. The only known side effect from short-term use of creatine supplements ranging from 5 to 20 grams per day is an increase in muscle mass -- which is generally a welcome side effect. Long-term studies are insufficient at this time, but anecdotal reports indicate that some users experienced diarrhea and muscle cramps when taking supplements for longer than 3 months at a time. These side effects reportedly vanished once use of the supplements was stopped.

In 1993, the Karolinska Institute conducted studies on the effect of creatine supplements for both strength (measured by peak torque), and weight gain (measured in pounds). The experiment to measure the effect of creatine on strength reported that participants taking creatine monohydrate were able to lift more weight for a longer period of time than the control group not taking creatine (Greenhaff). A separate study was done to measure body weight increase among creatine supplement users and the results showed an average weight increase of 2.4 pounds in a 1-month period (Balsom). The weight increase was attributed specifically to the higher levels of creatine in the muscles, which resulted in higher levels of ATP synthesis. Additional studies done at the University of Texas Southwestern Medical Center (1995) support the findings of the Karolinksa Institute.

These study results are significant to HIV-infected individuals seeking ways to maintain their weight and strength. While the studies were conducted specifically evaluating creatine monohydrate in the area of sports nutrition, they clearly show that creatine supplementation, when combined with regular resistance training, can increase muscle mass, strength, and body weight.

More than just a "vanity nutrient"

Creatine has been found to produce health benefits other than those related to sports training. A 1996 study by Dr. C. Earnest indicates that creatine supplementation can reduce both total cholesterol levels and fatty acids (called triglyderides) in the blood. An abnormal increase in cholesterol and triglycerides is being seen in many HIV-infected people taking protease inhibitors. The studies showing decreases in cholesterol and triglycerides are promising for people taking protease inhibitors, but additional studies need to be done specifically with the HIV-infected population before making any formal conclusions. Creatine's most obvious health benefit to those living with HIV is its potential to reduce or prevent the muscle-wasting syndrome common with this illness.

I think I want to try it, now what?

Before you start taking creatine monohydrate, consult your physician to evaluate possible side effects and discuss any drug interactions. One issue to be aware of is that creatine is excreted through the kidneys, making them work harder than normal. Individuals taking kidney-stressing drugs such as Cidofovir, Preveon, or Gancylovir need to think twice about the extra stress creatine will cause to this organ. There is no data that says creatine is harmful to people with HIV, but there have not been enough studies to conclude that it is both a safe and effective supplement.

Deciding on how much creatine to take, and when, is the most important decision for a creatine user. You need to take enough to get the benefits of increased muscle mass, body weight, and endurance, and at the same time not take quantities that are too high for your body to process safely. Additionally, if you are taking creatine monohydrate you must consume adequate amounts of water to properly assimilate the nutrient through your system. The recommended water intake when using creatine is eight 8-ounce glasses of water per day. (That's 64 ounces per day -- almost as much as Leonardo DiCaprio drank when filming The Titanic!) Insufficient water intake is the primary cause of side effects such as diarrhea and muscle cramps.

A common strategy for taking creatine is to take it in cycles. This process, called "cycling," consists of a loading phase, a maintenance phase, and a resting phase, as follows:

The loading phase normally lasts just 7 days. Consumption levels are between 12 to 20 grams per day based upon current weight and workout level. (For example, a 175-pound person working out 3 times per week for 1 hour per day would take 14 grams of creatine.) The less you weighed and worked out, the less creatine you would consume, and conversely, the more you weighed and worked out, the more creatine you would consume. The goal during the loading phase is to restore your creatine levels to 100% of their capacity.

The maintenance phase normally lasts for the 11 weeks following the loading phase. Maintenance dosages are determined by your weight and workout levels, just as in the loading phase, and range from 4 grams per day to 12 grams per day. (For example, a 175-pound person working out 3 times per week for 1 hour per day would consume 5 grams of creatine per day.) The goal of this phase is to maintain the levels of creatine achieved during the loading phase, without either overloading or depleting the system of creatine.

The resting phase lasts for 4 weeks following the maintenance phase. No creatine is taken during this time and normal exercise routines are continued. The goal of the resting phase is to allow the body to rest from the continuous cycle of processing creatine into muscle mass.

The resting phase is followed by repeating the entire cycle of loading, maintenance, and resting. There is debate among nutritionists and sports specialists whether a resting phase is needed since creatine is not an anabolic steroid and does not interfere with the natural function of the body. It is included here since this method of taking creatine is the most common among body building enthusiasts.

However, some studies have shown that with creatine less is more. One study demonstrated that 6 grams during a loading phase and 2 grams during the maintenance phase were just as effective as higher doses. Creatine comes in a crystallized powder form and should be taken with meals. The powder may be mixed with fruit juices, a protein drink, or water.

Wrap up

Creatine is a nutrient that occurs naturally in the body and helps promote muscle mass, strength, and endurance. When taken as a dietary supplement, creatine monohydrate may help to increase muscle mass and body weight. Creatine supplementation may also have additional benefits such as reducing cholesterol and triglyceride levels. For people infected with HIV, creatine may help to increase muscle mass that has been depleted by the activity of the virus, and may assist in maintaining body weight. Taken as a part of a complete health maintenance program, creatine supplementation may improve quality of life by improving general health and promoting a sense of wellbeing. Creatine monohydrate should be taken only after consultation with a physician, and only as part of a complete health maintenance program.

Balsom, P., K. Soderlund, B. Ekblom. "Creatine in humans with special reference to creatine supplementation." Sports Medicine 18(4): 268-280, 1994.

Greenhaff, P., A. Casey, A. Short, R. Harris, K. Soderlund, E. Hultman. "Influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary contraction in man." Clin Sci 84: 565-571, 1995.

Sahelian R., Tuttle D. Creatine: Nature's Muscle Builder. New York: Avery Publishing Group, 1997.

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