this is a post from another board. the author wasnt listed.
Creatine facts the supplement companies don't want you to know...
In an industry dominated by hype and half-truths, independent creatine facts are extremely hard to come by.
Pick up any health and fitness magazine looking for creatine facts. Chances are, you'll see numerous advertisements for the latest creatine-based formula, with each new product promising to be more effective than the last.
But does the type of creatine you use really make that much of a difference?
Truth is, the companies selling these supplements are very "selective" about the creatine facts and research they print. And because most of the magazines out there are either owned or supported financially (in the form of advertising) by supplement companies, getting to the truth can be extremely difficult.
Creatine facts
Just in case you were wondering...
... creatine does work!
Since the early 1990's, numerous studies have shown that creatine can increase lean muscle mass, and improve performance during repeated bouts of short-term, high-intensity exercise (such as weight training) [25].
A little-known creatine fact is the effect it has on cholesterol levels. Several months of
creatine supplementation has been shown to reduce very-low-density lipoprotein levels by 26% [8]. If you buy into the idea that high levels of cholesterol "cause" heart disease (a theory, which despite its popularity, is certainly not universally accepted), these findings suggest that creatine supplementation may offer health benefits.
One of the main reasons creatine has become so popular is that it leads to rapid gains in lean tissue (but not necessarily muscle tissue) in a matter of days. In fact, some research has shown that just five days of creatine supplementation (20 grams daily) leads to a three-pound gain in lean tissue [15]. This initial gain in weight is most likely due to an increase in water retention.
The benefits of creatine are also apparent when it's used for several months. Jeff Volek and a research team from Pennsylvania State University showed that 12-weeks of creatine supplementation combined with a weight-training program led to greater gains in muscle size and strength [24].
Creatine users gained 24% more strength in the bench press, and 32% more in the squat.
Subjects using creatine also gained approximately twice as much muscle.
Creatine supplementation has also been shown to improve sporting performance in soccer player's [16]. Spanish researchers examined a group of players from Athletic Club de Bilbao, one of Europe's leading soccer teams. The players were divided into two groups. Group one was given 20 grams of creatine per day for six days. Group two received a dummy supplement that had no effect.
Following supplementation, the players completed a series of tests designed to closely match the activity of a competitive soccer game. These included a number of sprinting and jumping tests. Creatine resulted in faster sprinting times, and also led to improved jumping performance.
However, creatine alone DOESN'T work for everyone. Two or three people out of every 10 don't respond to supplementation (they're called -- surprisingly enough -- non-responders). I'll explain a little more about non-responders (and how to turn yourself into a "responder" in just a moment).
First, here's a little background on creatine...
Discovered in 1832, your body forms creatine from three amino acids (glycine, arginine, and methionine) [2]. Once synthesized, creatine is transported to the muscle, heart and brain, where it's used as an energy source.
To understand how creatine supplementation works, it's important to know a little about where your body gets its energy from.
Energy
Different countries throughout the world use different forms of currency. In much the same way, your body has its own energy currency. Known as adenosine triphosphate (or ATP for short), it provides energy for every move you make and every chemical reaction that occurs in your body.
ATP is constantly broken down and "re-created". Energy is released when one of the phosphates that form ATP is "broken off". During high-intensity exercise (such as a 60-meter sprint), the stores of ATP are depleted rapidly, and a quick method of reattaching the phosphate is required.
That's where creatine comes in.
When your body stores creatine, some of it is attached to a phosphate group. Whenever ATP "loses" a phosphate, creatine "donates" one of its own to support the resynthesis of ATP. The fatigue you experience during short bouts of high-intensity exercise is associated with an inability of muscle to maintain a high rate of ATP resynthesis from creatine phosphate.
In other words, if ATP is broken down more quickly than it can be resynthesized, you'll run out of energy.
Creatine supplementation has been shown to increase the levels of creatine in muscle. In fact, short-term creatine supplementation (15-30 grams per day for 5-7 days) increases total creatine stores by 15-30% and creatine phosphate levels by 10-40% [11]. This increase in creatine levels can improve your ability to perform high-intensity exercise [26].
Creatine uptake
You've probably seen plenty of creatine formulas that promise to increase uptake and absorption by several hundred percent compared to regular creatine. EAS, for example, have recently produced a product called InsuLoad HP™, which promises to increase creatine uptake to a far greater extent than plain creatine.
But what does creatine uptake actually mean?
Creatine uptake refers simply to the rise in the levels of creatine in the muscle. The degree of improvement in exercise performance is closely linked to creatine uptake. According to some research, a rise of at least 20 mmol per kilogram of dry muscle is necessary before the effects of supplementation become apparent [10].
So, do any of these expensive formulas really work that much better than regular creatine?
First off, it's important to note that the addition of these various "insulin potentiators" or patented "transport systems" do NOT increase uptake. Rather, they increase the rate of uptake.
Here's what I mean.
Your body has a "pool" of creatine. Not surprisingly, supplementation helps to increase the amount of creatine in that pool. And, just like a swimming pool can only hold so much water, there's only so much creatine your body can store.
Think of it like this...
Imagine you were using a hose to fill a swimming pool. You could open the tap up fully, and the pool would fill with water more quickly. Or, you could leave the tap partially closed, in which case the pool would take longer to fill.
However, once the pool is full, that's it! It's the same with creatine and your muscles. You can take creatine with as many glucose "transport agents" or insulin "potentiators" as you like -- it won't make the slightest bit of difference to your creatine levels. Once your muscles are saturated with creatine, any excess is lost in the urine.
Loading
Typically, most people "load" with 20-30 grams of creatine each day for the first week of use. One of the reasons that creatine loading has been used so extensively is because it raises creatine levels very rapidly.
However 30 days of low-dose creatine supplementation raises the concentration of creatine in your muscles to the same extent as 7 days using higher doses.
For example, studies show that six days of creatine supplementation (20 grams per day) leads to a 20% rise in muscle creatine concentration [13]. Test subjects were able to maintain this elevated level even when using just 2 grams of creatine per day. What's interesting is that a similar increase in creatine levels occurred in subjects using just 3 grams of creatine per day for 30 days.
In other words, unless you're looking for a rapid improvement in performance, there is little need to load with creatine.
Dr. Mark Tarnopolsky, in a presentation at the American College of Sports Medicines' Health and Fitness conference, also points out that creatine loading is unnecessary. According to Tarnopolsky, three grams of creatine daily is sufficient to keep the muscle saturated.
It's important to point out that some people don't seem to respond to creatine as well as others. They're known as non-responders. Combining creatine with carbohydrate, or a combination of carbohydrate and protein, has been shown to reduce the number of non-responders.
Here's why...
Insulin
The transport of creatine into the muscle is assisted by the hormone insulin. This may be due to the effect insulin has on cellular metabolism. Insulin has been shown to cause protein deposition in cells by increasing the rate of amino acid transport through cell membranes. Consequently, combining creatine with an insulin-releasing agent (such as dextrose) can significantly increase the rate of creatine uptake during supplementation.
Some evidence that this is the case comes from a research team based at Queen's Medical Center, Nottingham [20]. They compared a high-carbohydrate (94 grams) solution with a mixture of protein (50 grams) and carbohydrate (47 grams).
The results (shown below) indicate that a combination of carbohydrate and protein is just as effective as a high-carbohydrate solution at promoting creatine uptake.
TABLE 1: Creatine uptake following ingestion of carbohydrate or carbohydrate and protein.
Method Creatine Uptake
Placebo 38%
Low carbohydrate (50g) 44%
High carbohydrate (94g) 48%
Protein (50g) & carbohydrate (47g) 48%
Exercise
Exercise has also been shown to increase the rate of creatine uptake. This was demonstrated in the early 1990's by a research group led by Professor Roger Harris [11]. Consuming 20-30 grams of creatine per day for 2-3 days, subjects exercised one leg as hard as possible, while resting the other leg.
Levels of creatine in the muscles of the leg that had been exercised rose by 37.6%.
In the rested leg, creatine levels only increased by 25.7%.
Similar findings have also been reported by a team from the University of Nottingham Medical School, England [18].
So, it appears that the best time to use creatine would be after you finish training. It's also important to note that creatine taken during (or slightly before) exercise appears to "interfere" with the performance improvements linked with prior creatine loading [21].
Another factor affecting the individual response to creatine is the level of creatine in the muscle before starting supplementation [11]. This can be influenced by the type of diet consumed by subjects prior to using creatine. Foods such as herring, salmon, tuna, beef and pork all contain in excess of 4 grams of creatine per kilogram [2]. Diets high or low in these particular foods could account for the large variation in the rise in creatine levels following supplementation.
Because they don't eat meat or fish (two foods that contain creatine), vegetarians usually respond well to supplementation, as they often have very low levels of creatine in their muscle cells to begin with [6].
Table 2: Approximate creatine content in different foods.
Food Type Creatine content (grams per kg)
Shrimp Trace
Cod 3
Herring 6.6 - 10
Plaice 2
Salmon 4.5
Tuna 4
Beef 4.5
Pork 5
Milk 0.1
Cranberries 0.02
NOTE: The fish and meat were freeze dried, extracted in percholic acid and neutralized with potassium hydrogencarbonate (milk and cranberries were extracted in the same way). Creatine concentration was determined enzymatically using spectrophotometer (analyzed at a wavelength of 340nm).
Cycling
While many people choose to cycle creatine (using creatine for a number of months before discontinuing its use for several weeks), there's little research to show that this is necessary. Cycling creatine is based on the theory that your body eventually becomes "resistant" to the beneficial effects of supplementation.
Specifically, the prolonged use of creatine is supposed to downregulate the parts of the cell that transport creatine into the muscle. While this has been shown to occur in rats, a recent study, presented at the Canadian Society For Exercise Physiology annual meeting, showed that eight weeks of creatine supplementation has no effect on creatine transporters in humans.
In fact, Dr. Jeffrey Stout, assistant professor at Creighton University and co-director of the human performance research lab, says he hasn't stopped using creatine since 1994!
Although the gain in weight during the first week of creatine supplementation is primarily down to a rise in water weight, this increase in cell volume may trigger protein synthesis and minimize protein breakdown [12]. This may be the reason long-term studies demonstrate that continuous, low-dose creatine supplementation can increase lean muscle mass [7].
Limitations
Although the research supporting the use of creatine as an aid to performance is pretty solid, there are also some conditions under which it doesn't seem to work quite so well. Its effectiveness depends on the length and amount of supplementation, the type of exercise you do, and the work to rest ratios used in your workout.
Small amounts of creatine (1 gram or less) have little effect on circulating creatine concentrations, whereas higher doses (5 grams) result in an approximately fifteen-fold increase [11].
High doses of caffeine also appear to "block" the effects of creatine [22]. Creatine and caffeine taken together both raised muscle creatine phosphate levels to the same extent as creatine supplementation only, whereas it was only the latter treatment that improved performance.
That said, the study in question used very large doses of caffeine (5 mg of caffeine per kilogram of bodyweight). Moreover, previous research has used creatine dissolved in warm caffeinated drinks, such as coffee or tea. As such, it's likely that only very high doses of caffeine should cause concern.
Creatine supplementation has little effect on performance in sprints lasting 6-60 seconds when long recovery periods (5-25 minutes) are used between sprint trials [4]. This can be seen when comparing studies using similar work times, but with different rest intervals.
Creatine was found to improve performance when short bouts of high-intensity cycling were separated by 30 seconds of rest [1].
In contrast, when the rest period lasted two minutes, there was no such improvement in performance [17].
Without supplementation, the resynthesis of creatine phosphate reaches almost 80% of resting levels 4 minutes after a 30-second bout of high-intensity exercise [3]. As a result, the beneficial effect that supplementation has on the resynthesis of creatine phosphate will become less apparent with longer rest periods (greater than 60 seconds) between bouts of exercise.
Side effects
Creatine users seem to be more susceptible to cramps, muscle spasms, and even pulled muscles. While no clinical study is available to support these claims, personal experience has taught me that exercise in the heat without consuming enough water (while using creatine) DOES increase the risk of muscle cramp!
There are also suggestions that supplementation may increase liver and kidney stress. No studies to date have reported significant elevations in liver enzymes in response to creatine supplementation. Of course, people with existing liver or kidney problems, or those that are predisposed to such ailments, should be cautious about using creatine.
Studies focusing on the medical applications of creatine using continuous low doses (less than 2 grams per day) for up to 5 years have shown no adverse side effects [19, 23].
So, based on the research to date, what's the best way to use creatine?
1. There's very little evidence to suggest that creatine needs to be loaded. Smaller doses (3-5 grams) taken over 30 days will saturate your muscles with creatine to the same degree as 20 grams taken for six days.
2. The best time to take creatine appears to be after exercise. Not only does this increase the rate of creatine uptake, but it also increases glycogen levels (glycogen is the name given to carbohydrate stored in your muscles). Approximately 0.06 grams of creatine per kilogram of weight (or 0.027 grams per pound) should be sufficient to raise creatine levels. For example, someone weighing 120 pounds would consume around 3 grams of creatine after exercise. A 220-pound individual, on the other hand, would consume roughly 6 grams.
3. Although the ways in which creatine promotes muscle growth over the period of several months is still the subject of some debate, it's likely to work by increasing protein synthesis, reducing protein breakdown, or increasing the amount of work you can perform in each workout. Most likely, it's a combination of all three. Because creatine promotes an anabolic environment favoring muscle growth, continuous low-dose supplementation may be more effective than the common practice of cycling creatine.
There's also very little evidence to suggest that effervescent, or
micronized creatine products offer any advantages over plain creatine monohydrate. While supplement companies will continue to promote their "advanced" creatine blends, there's only so much creatine your muscles can store. Once creatine levels reach their upper limit, any excess will be simply flushed down the toilet.
References
1. Balsom, P.D, Ekblom, K., Soderlund, B., & Ekblom, B. (1993). Creatine supplementation and dynamic high-intensity intermittent exercise. Scandinavian Journal of Medicine and Science in Sports, 3, 143-149
2. Balsom, P.D., Soderlund, K., & Ekblom B. (1994). Creatine in humans with special reference to creatine supplementation. Sports Medicine, 18, 268-280
3. Bogdanis, G.C., Nevill, M.E., Boobis, L.H., & Lakomy, H.K. (1996). Contribution of phosphocreatine and aerobic metabolism to energy supply during repeated sprint exercise. Journal of Applied Physiology, 80, 876-884
4. Burke, L.M., Pyne, D.B., & Telford, R.D. (1996). Effect of oral creatine supplementation on sibgle-effort sprint performance in elite swimmers. International Journal of Sport Nutrition, 6, 222-233
5. Casey, A., Constantin-Teodosiu, D., Howell, S., Hultman, E., & Greenhaff, P.L. (1996). Creatine ingestion favorably affects performance and muscle metabolism during maximal exercise in humans. American Journal of Physiology, 271, E31-E37
6. Delanghe, J., De Slypere, J.P., De Buyzere, M., Robbrecht, J., Wieme, R., & Vermeulen, A. (1989). Normal reference values for creatine, creatinine, and carnitine are lower in vegetarians. Clinical Chemistry, 35, 1802-1803.
7. Earnest, C.P., Snell, P.G., Rodriguez, R., Almada, A.L., & Mitchell, T.L. (1995). The effect of creatine monohydrate ingestion on anaerobic power indices, muscular strength and body composition. Acta physiologica Scandinavica, 153, 207-209
8. Earnest, C., Almada, A., & Mitchell, T. (1996). High-performance capillary electrophoresis-pure creatine monohydrate reduces blood lipids in men and women. Clinical Science, 91, 113-118
9. Green, A.L., Simpson, E.J., Littlewood, J.J., Macdonald, I.A., & Greenhaff, P.L. (1996). Carbohydrate ingestion augments creatine retention during creatine feeding in humans. Acta Physiologica Scandinavica, 158, 195-202
10. Greenhaff, P.L., Bodin, K., Soderlund, K., & Hultman, E. (1994). Effect of oral creatine supplementation on skeletal muscle phosphocreatine resynthesis. American Journal of Physiology, 266, E725-E730
11. Harris, R.C, Soderlund, K., & Hultman, E. (1992). Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clinical Science, 83, 367-374
12. Haussinger, D. (1996). The role of cellular hydration in the regulation of cell function. Biochemical Journal, 313, 697-710
13. Hultman, E., Soderlund, K., Timmons, T.A., Cederblad, G., & Greenhaff, P.L. (1996). Muscle creatine loading in men. Journal of Applied Physiology, 81, 232-237
14. Kreider, R.B., Ferreira, M., Wilson, M., Grindstaff, P., Plisk, S., Reinardy, J., Cantler, E., & Almada, A.L. (1998). Effects of creatine supplementation on body composition, strength and sprint performance. Medicine and Science in Sports and Exercise, 30, 73-82
15. Mihic, S., MacDonald, J.R., McKenzie, S., & Tarnopolsky, M.A. (2000). Acute creatine loading increase fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women. Medicine and Science in Sports and Exercise, 32, 291-296
16. Mujika, I., Padilla, S., Ibanez, J., Izquierdo, M., & Gorostiaga, E. (2000). Creatine supplementation and sprint performance in soccer players. Medicine and Science in Sports and Exercise, 32, 518-525
17. Redondo, D.R., Dowling, E.A., Graham, B.L., Almada, A.L., & Williams, M.H. (1996). The effect of oral creatine monohydrate supplementation on running velocity. International Journal of Sport Nutrition, 6, 213-221
18. Robinson, T.M., Sewell, D.A., Hultman, E., & Greenhaff, P.L. (1999). Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle. Journal of Applied Physiology, 87, 598-604
19. Sipila, I., Rapola, J., Simell, O., & Vannas, A. (1981). Supplementary creatine as a treatment for gyrate atrophy of the chloroid retina. New England Journal of Medicine, 304, 867-870
20. Steenge, G.R., Simpson, E.J, & Greenhaff, P.L (2000). Protein- and carbohydrate-induced augmentation of whole body creatine retention in humans. Journal of Applied Physiology, 89, 1165-1171
21. Vandebuerie, F., Vanden Eynde, B., Vandenberghe, K., & Hespel, P. (1998). Effect of creatine loading on endurance capacity and sprint power in cyclists. International Journal of Sports Medicine, 19, 490-495
22. Vandenberghe, K., N. Gillis, M. Van Leemputte, P. Van Hecke, F. Vanstapel, and P. Hespel. (1996). Caffeine counteracts the ergogenic action of muscle creatine loading. Journal of Applied Physiology, 80, 452-457
23. Vannas-Sulonen, K., Sipila, I., Vannas, A., Simell, O., & Rapola, J. (1985). Gyrate atrophy of the chloroid and retina: a five year follow-up of creatine supplementation. Opthalmology, 91, 1719-1727
24. Volek J.S., Duncan, N.D., Mazzetti, S.A., Staron, R.S., Putukian, M., Gomez, A.L, Pearson, D.R, Fink, W.J., & Kraemer WJ. (1999). Performance and muscle fiber adaptations to creatine supplementation and heavy resistance training. Medicine and Science in Sports and Exercise, 31, 1147-1156
25. Volek, J.S., & Kraemer W.J. (1996). Creatine Supplementation: Its effect on human muscular performance and body composition. Journal of Strength and Conditioning Research, 10, 200-210
26. Williams, M.H., & Branch, J.D. (1998). Creatine supplementation and exercise performance: An update. Journal of the American College of Nutrition, 17, 216-234
