Sports Nutrition – Creatine Supplementation
Creatine Supplement for Sports
By Andrea Holwegner, Health Stand Nutrition Consulting Inc
What is it?
Creatine is a non-essential compound that can be obtained in the diet from fish, beef and chicken. It is also produced in our bodies by the liver, pancreas and kidneys from the amino acids glycine and arginine. Ninety-five percent of the body’s creatine is stored in skeletal muscle, containing on average approximately 5g of creatine/kg.
What does creatine do in the body?
The primary function of creatine is to produce energy for exercises like sprinting and weight lifting that involve repetitive bouts of brief intense efforts. The creatine fuel system is the only way the body can provide enough energy to support these tasks. Therefore it is hypothesized that if you increase creatine stores through supplements you will have a greater energy reserve available to perform these activities.
Who could consider using it?
Athletes whose sport requires high intensity, repeated bouts of exercise may benefit from creatine supplementation, such as sprinters and weight lifters. In controlled lab tests creatine supplementation improved short term performance (less than 30 seconds), with weight lifters by allowing them to do more reps before fatigue. In some weight lifters there is also improved recovery time between sets but this is less common. There is no convincing evidence that creatine improves performance for endurance athletes or exercise of longer duration (more than 90 seconds), but it did produce faster results for a sprinting exercise after an endurance phase. Note that these studies are done in controlled laboratory settings. Studies performed in the field rarely show improved performance for a single event.
Creatine supplements may aid healthy untrained young adults, but only in conjunction with a healthy diet and aggressive exercise program. It is not recommended for teenagers under the age of 18 as the effects on growth are not known.
What dose is used in research trials?
The number one factor affecting how much creatine will be taken up by the muscles is the amount of creatine already in storage. For example vegetarians often have the biggest increase in muscle creatine from supplementation because lower stores means higher uptake. There is considerable variation in the levels of increase of muscle creatine following supplementation, with some people being non-responders (little to no increase), and some being high responders (increase of 30%).
Literature shows that a brief (5 days) high dose creatine loading phase (5 g four times per day) is sufficient to saturate muscles with creatine. During this time researches found that subjects gained approximately 1-3 kg of body weight. Any amount over 20 g of creatine per day is not useful since it will be converted to another compound called creatinine and excreted in the urine. Following these five days, a maintenance phase of 2-5 g/d is recommended, with some companies also suggesting cycling with two months on and then one month off but there is limited research to confirm this. Some supplements also contain dextrose, as a few studies suggest that ingesting creatine with glucose may increase uptake by about 9%.
Are there different kinds of creatine supplements?
Creatine supplements can contain creatine monohydrate, creatine citrate or creatine phosphate and are marketed to increase muscle mass. They also come in a variety of forms, such as powder, liquid or serum, pills, gum, and effervescent powder. The powder is the most popular and cheapest supplement form. It is simply mixed with water or juice, but can have a gritty taste. A micronized (finely ground) form is also available to help decrease the grittiness. The disadvantage to the powder is that it is not effectively absorbed, with 40-50% lost to stomach acid and enzymes. Creatine powder absorbs water, sometimes resulting in an upset stomach and dehydration, therefore it is important to ensure you drink enough water. Companies recommend taking it one hour before working out, to give the creatine time to reach your muscle cells.
Creatine in liquid (serum) form is a more effective delivery system with a higher absorption rate, but it must be stabilized with chemicals or else it will break down into creatinine in solution. It reaches your muscles faster, meaning you can take less, closer to the time you work out. The pills are basically the same as the powder, with no mixing involved. The added disadvantage of these is that you can’t vary the dosage, they usually contain 5 g of creatine per pill. The gum is not very popular and therefore harder to find. The effervescent variety you drop in glass and it fizzes. It may have increase absorption compared to the powder but again they come in per-made packages so it is hard to vary dosage.
What should I look for when purchasing creatine?
When purchasing a creatine supplement remember that all supplements are not the same. Prices vary and you may just be paying for the name brand in some cases. Good things to look for are lab assays on the bottle telling you how pure the creatine is, and ingredient lists telling what else is put in the supplement. Good quality products will offer 100% pure creatine, no fillers, and a 100% money back guarantee. You can purchase creatine supplements over the internet, in gyms and health clubs, and in health food stores.
Some approximate price ranges for a one month supply are listed below:
- Serum: $40-60 for 250 mL
- Powder: $17.50-23 for 500mg; $30-35 for 1000mg
- Micronized: $35-50 for 1000g (200 servings)
- Effervescent: 30 packages $30-40
- Cr bars (12): $20 – 27 (5 g creatine, 20 g protein, and 280 calories/bar)
- Capsules: 750 mg (300 capsules), $24-30 (3.5 g creatine/capsule)
Is it permitted for use in sport?
Creatine is not banned by the World Anti-Doping Agency or the IOC, however some schools, teams and sports have instituted policies prohibiting its use. It is legal to purchase and possess. It is also not banned in major sports leagues – NFL, NBA, MLB, NCAA, and the Olympics. It is impossible to ban because it is found in many foods, making testing and setting appropriate limits very difficult.
Are there any adverse side effects?
At this time there does not appear to be any adverse health effects of supplementing with creatine. Caffeine is a drug that may nullify the performance enhancing effects of creatine. Studies find that up to 21 months of use does not adversely affect markers of health (blood tests) in intensely training athletes. It should be noted that no long term effects are noted because of no long term studies exist. Immediate side effects include muscle cramping, spasms, hamstring pulls, diarrhea, and stomach cramps. The quick weight gain from water retention (3 lbs/week) can be considered a side effect in some sports, for example lightweight wrestling, endurance events, judo, and gymnastics, where either endurance or a sleek physique is important to performing well. Athletes are now ingesting creatine for weeks or months at a time, not simply utilizing the loading phase (5 days) to increase performance at a specific event, which is what most studies to date have examined. Instead many athletes are using it chronically to increase muscle strength, muscle size, and body mass during training, of which no scientific studies have been conducted.
Take home message
While supplementing with creatine may enhance short repeated bouts of intense exercise, it has no effect on a performance at a single event, especially for endurance events. Ensure that you fully research your product, and review your decision with a sports dietitian before beginning supplementation.