Is Creatine Safe?

Creatine monohydrate is acommon supplement in the bodybuilding and fitness world. But is it needed? Is it effective? And, is it safe? Well, let's have a look.

How Does Creatine Work?

Our bodies produce a source of creatine known as phosphocreatine (PC) which is used as an energy source during short term explosive exercise such as jumping, lifting, and sprinting. It is also the energy source that helps us make the transition to the steady state of oxygen uptake during submaximal aerobic exercise.

Because of PC's role in short term explosive exercise, fitness buffs have been interested in its ability to increase strength and muscle size. For athletes involved in repeated short burst-type movements, creatine has proven to be useful in resisting fatigue and improving performance. This is especially true for hockey players, football players, and even soccer players to some degree.

The reason creatine is helpful in these sports is that it helps restore your muscle's ATP (energy) stores more rapidly. Therefore, it allows you to recover quicker, minimize the build up of lactic acid, and perform repeated bouts of intense exercise. This obviously has benefits to athletes on the field (or ice) and fitness buffs in the gym.

Creatine Stores and Loading Plans

The total creatine concentration in muscle is about 120 mmol/kg. Our bodies excrete roughly 2 grams of creatine per day. Generally, these 2 grams are replaced by diet (1 gram) and by synthesis (1 gram) from the amino acids arginine, glycine, and methionine. However, it should be noted that since vegetables do not contain creatine, vegetarians show lower levels of muscle creatine which, upon creatine supplementation, rise to a level higher than in meat-eaters. Furthermore, caffeine has been shown to counteract the effect of creatine loading and thus maintaining a healthy diet is important for its effectiveness.

The first step in a typical creatine monohydrate "loading" plan consists of adding 20-25 grams to the diet per day for 5-7 days. This usually results in a 20% increase in muscle creatine stores. Afterwards, a maintenance dose of about 5 grams per day is recommended. However, in my experience and from research recommendations, it may be helpful to cycle creatine supplementation. For example, you could take it for one month and then cycle off of it for one week and then repeat.

Creatine's effectiveness will vary between each person since everyone has a different "starting point" of creatine stores. For me, I have lower creatine stores (perhaps because I'm mainly vegan - I don't animal products that often) and thus, in the past, creatine supplementation was helpful for me in my days playing professional soccer.

There is great variability in responses to creatine for a few reasons:

• individuals with lower initial values (ie. vegetarians, vegans) have greater increases, and some individuals with high pre-supplementation phosphocreatine levels may not respond to creatine supplementation. Thus, we have responders and non-responders.

• The ingestion of glucose with creatine reduces the variation and enhances uptake.

In general, the short-term loading scheme appears to improve the ability to maintain muscular force and power output during various bouts of exhaustive exercise. For instance, shuttle runs, beep tests, high intensity interval training, etc...

Creatine's Effect on Performance, Strength, and Muscle Size

The mechanism for any increase in athletic performance may be only indirectly related to the creatine itself. For example, greater gains in strength achieved in a weight training program may be mediated by your ability to increase the intensity of your training, which would, in turn, allow you to lift more weight, take less rest, and allow for a greater physiological adaptation to the strength training.

When it comes to increases in muscle size creatine has been shown to be short term fix, if at all. Many people who want to "gain size" use creatine to bulk up but the reality is that any bulking up that occurs is simply a matter of water retention. It appears that creatine supplementation improves the muscle's ability to retain water, thus making it look more plump. This should not be confused with actual muscle hypertrophy since once creatine supplementation stops, the muscles usually regain their initial size.

Is Creatine Supplementation Safe?

Ah, the big question. Well, the good news is that the majority of the literature shows the creatine is safe. However, long term studies (>10 years) have not been conducted so for right now we won't know what effects it may have down the road. However, I've used it, feel safe recommending it, and believe that it is a helpful performance aid in certain situations.

However, I DO NOT RECOMMEND creatine for buiding size because it does not create any additional protein synthesis beyond the fact that it might allow you to lift more weight.

Some of the side effects that have been noted with creatine use include gastrointestinal distress, nausea, and muscle cramping. 

Otherwise, the use of creatine in healthy individuals is generally considered safe. As mentioned, studies have not yet been able to demonstrate either long-term or short term creatine supplementation result in adverse health effects.

Creatine supplementation using proper cycling and dosages (as we mentioned above) has not been linked with any adverse side effects beyond occasional dehydration due to increased muscular water uptake from the rest of the body.

However, one side effect that has been noted by some research, and myself as well, is that creatine supplementation may produce lower leg pain by causing an increase in the anterior pressures of the lower leg. This is usually found in post-creatine use when at rest and after exercise. Normal at-rest pressures have been found to be highly elevated by subjects who used creatine within the prior 35 days when compared to no supplementation. 

This can produce an extreme amount of pain in the lower leg due to the rigidity of the anterior compartment of the lower leg and lack of fluid drainage out of the compartment. It may also be exacerbated by the increase of water content in the muscle fibers, putting more pressure on the anterior compartment. This is known as Compartment Syndrome and I can tell you from my own experience that it is not pleasant. I used to get it really bad when I used creatine back in the day to the point where I would have to stop running because I could barely feel my feet.

So there you have it - a nice summary of creatine monohydrate. Is creatine safe? I think so, otherwise I would never have used it or recommended it. But you need to ask yourself why you're using it, consider the cost, and evaluate its effectiveness. 

References:

Burke DG, Chilibeck PD, Parise G, Candow DG, Mahoney D, Tarnopolsky M (2003). "Effect of creatine and weight training on muscle creatine and performance in vegetarians". Medicine and science in sports and exercise 35 (11): 1946–55.

Powers, S. & Howley, E. (2001). Exercise Physiology: Theory and Application to Fitness and Performance. McGraw Hil: New York.