You're squeezing out that last rep on the seated calf machine, your soleus and gastrocnemius muscles burning as you wince in pain, beads of sweat trickling down your cheeks.
You suddenly stop, clench your right calf and the sweat starts to turn to tears as you grit your teeth and curse "cr@p, yet another cramp, I have to quit taking creatine or drink a gallon of water a day to prevent dehydration!"
But is it really the creatine that is causing your cramps? Likewise, is creatine to blame for all the cases of dehydration we read about in the sports section of our local newspaper? Or have the supplement scandals and steroid use in pro sports made all other supplements guilty by association?
Even some researchers have theorized that creatine supplementation could shift our body's fluid balance such that our cells fill with water and the environment outside of our cells, the extracellular compartment, more closely resembles a lake in Southern California - short on fluid.
This situation, fluid-filled cells sitting in an environment with little fluid could theoretically lead to cramping, dehydration and wacked-out electrolytes.
This theory and the athletes clutching their calves and blaming creatine as they wince in cramp-induced pain, have led to a plethora of safety studies on creatine. Luckily, the scientists at the University of Oklahoma reviewed these studies and weeded out the truth from the fictional tales that surround us.
What did they find? Studies analyzing fluid volume indicate that creatine does in fact increase total body water and intracellular water but has no effect on extracellular water (the water in that Southern CA lake). And, much to the surprise of out of shape, overweight athletes who need to point their finger at anything other than themselves, creatine might actually enhance performance in hot and/or humid conditions.
That's right, not only is creatine not to blame when it comes to cramps and heat illnesses, but, it seems creatine helps us regulate our body temperature, reduce sweat rate, exercising heart rate (so that our heart isn't working so hard in the heat) and maintain our red blood cells per volume of blood (i.e. hematocrit).
So what about the plethora of studies showing that athletes who were taking creatine reported cramping, GI distress, diarrhea, and upset stomach?
Two large studies, consisting of 219 collegiate athletes and 1,349 high school football players, respectively, did not control for other supplements used. In addition, in both studies the athletes were participating in hot environments.
At Baylor University, researchers examined 72 NCAA Division 1 football players who chose to consume or not consume creatine. This particular study found that the creatine group experienced significantly less muscle cramping, muscle tightness, muscle strains, heat illness, dehydration and total injuries than the group not taking creatine.
Alas, what about our kidneys? Doesn't creatine damage them over time? Scientists took healthy sedentary males aged 18-35 years and examined the effect, if any, that creatine would have on renal functioning.
In a randomized, placebo-controlled, double-blind fashion, subjects were given either 10 grams of creatine or a placebo (sugar) for 3 months during which they exercised aerobically 3 times a week for 40 minutes per session. Measures of kidney functioning, including serum creatinine, serum and urinary sodium and potassium were determined at baseline and at the end of the study.
Cystatin C was also assessed pre and post as well as four weeks into the trial. Of the parameters examined, cystatin C decreased over time (which signifies an increase in the glomerular filtration rate; cystatin C actually will increase with impaired kidney functioning) and serum creatinine decreased in the placebo group. No other parameters changed indicating that 3 months of 10 g/day creatine supplementation does not impair kidney functioning in healthy males.
Yes, this study was done in males as are most of these studies because researchers do not need to control for the hormonal fluctuation that happens in women (though this can be done) and just because researchers often study men - especially when it comes to sports supplements.
If you are interested in being a research subject, contact your local university's exercise science department and ask them what studies they anticipate in the future.
Previous articles about creatine have established the benefits of creatine supplementation for strength gains and performance in short, intense bouts of exercise.
Together, this review study and randomized clinical trial indicate that creatine is also a safe supplement for healthy individuals. In addition, creatine may decrease one's risk of dehydration during exercise by increasing total body water.
The recommended dose of creatine is approximately 5 grams per day for men and 2-3 grams/day for women during periods of intense training. So go ahead, and give creatine a shot - it may help you do more than just add great muscle definition.
- Dalbo VJ, Roberts M, Kerksick C, Stout J. Putting the myth of creatine supplementation leading to muscle cramps and dehydration to rest. Br J Sports Med. 2008 Jan 9; [Epub ahead of print].
- Gualano B, Ugrinowitsch C, Novaes RB et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol. 2008 Jan 11 [Epub ahead of print]