Creatine

I’ve been asked a lot lately about creatine, so here’s what you need to know:

Creatine monohydrate (Cr), the popular supplement form has been widely available and well studied for over ten years.  In this form it can be considered safe, although any supplement carries with it some degree of risk discussed in previous posts.

The results of Cr supplementation on training and performance have demonstrated benefits in many cases, and no benefit in others.  The one near-constant result in the studies is that Cr results in significant increases in body mass.  These gains are rapid (occurring within the first 2 weeks), and temporary (return to normal baseline shortly after supplementation cessation) because the increase comes from water retention.  You see, once creatine monohydrate passes through the digestive system, into the blood stream it eventually makes its way into the muscles cells.  Here it picks up a phosphate molecule generated by the metabolic processes in the muscle.  It now becomes creatine phosphate (PCr) where it sits in the watery muscle cell, until such a time that the phosphate is needed.

Since it is stored in a watery medium, increasing Cr results in increasing water within the muscles.  This water weight gain is typically in the 5-10 pound range.  Is this good? Possibly.  For athletes, increasing body weight, unless its actually the contractile components (the structural proteins that generate force), results in a decrease in performance.  Increasing fat, water, or uniform/equipment equal to 2% of body mass (3-5 pounds) decreases vertical jump by almost 2 inches and slows 40yard sprint speed and short agility by almost 1/3 of a second.  Make that a 5% increase and we’re talking 3 inches and half a second.  This is a big problem, particularly in season.

For body builders, this may help with your vanity and insecurity early on, but it just represents more weight to be cut prior to competition.  There are some anecdotal reports of increased incidences of muscle cramping when cycling off of CR, especially when combined with activity in hot environments.

Does it allow you to train more or train harder? It can. To fuel muscle contraction, adenosine triphosphate (ATP) is required, the chemical reaction breaks ATP into adenosine diphosphate (ADP) and a free phosphate.  In the process this releases energy which the contractile proteins use to do their thing.  We can only store a tiny amount of ATP in our muscle cells, so we need to somehow reattach the free phosphate to the ADP to make ATP.  Creatine phosphate is one readily available source that will give up is phosphate.  We can store a bit of CrP naturally, and about 40% more with supplementation.  As the need for energy persists other forms become available, mainly forms of sugar.  These sugar pathways are a bit slow to get going at optimal levels, so CrP can help bridge that time frame.  As soon as the activity stops (the set or lap is over) or decreases to moderate levels, the ATP and CrP reserves are restored by the sugar pathways which continue to operate until everything is back to “normal” resting levels.

Natural levels of CrP are typically depleted after about 10-20 seconds, depending on the training status of the individual.  The sugar pathways, also depending on training status, take about that same time to get going at full speed.  This is assuming the activity is very high intensity; spints, or loads in the 3-8 repetition maximum (RM) range.  These loads are often used for increasing strength, so Cr supplementation can be beneficial here allowing more reps at a given load. To get a hypertrophic (increase in muscle mass) effect, loads corresponding to an 8-15RM are generally superior, as they permit the 8-12 repetitions per set typically advocated for hypertrophy training.  In this case, Cr supplementation is unlikely to be beneficial.

For sprint training, the goal is increased linear speed.  This requires rest periods in the 5-10 minute range for optimal development of the neuromuscular system. The work periods are kept under 10 seconds.  Obviously here, Cr supplementation is of no physiological benefit as the work intervals are too short to deplete CrP, and recovery periods are many times longer than required to restore resting CrP levels.  There may be some benefit from training with increased mass attached to your body, however this is typically best in a belt or vest form so that some training is done at competition weight (unloaded) in combination to the loaded repetitions.

For conditioning (interval work-outs) CrP supplementation may allow more high quality repetitions in a given workout by slightly increasing the time/distance, or decreasing rest duration.  This increased training volume may be beneficial.  Shuttle runs, medicine ball work, sled drills, or calisthenics all can involve large muscle masses working at maximum power (force x distance x speed) for the requisite 20 second burn.

To sum up:  Supplementation with creatine monohydrate has demonstrated a to have a positive effect on training adaptation in studies where the exercises were performed against heavy loads, at maximal effort for 10- 20 seconds, with rest periods under 2 minutes between sets.  The time for completion of each set is the variable that should be progressed with this protocol (as opposed to increasing the load).  The resulting training adaptation will be specific to this type of repeated burst of maximal efforts that last between 10 and 20 seconds.  As I write this, I can’t think of a single sport where this is the type of metabolic demand in competition, though it can have it’s place in a periodized training programme.

With other training protocols, creatine monohydrate supplementation typically has no positive effect on training adaptation.

With any type of training, or no training at all, creatine monohydrate supplementation will result in increased lean body weight (mostly in the form of water mass) during the supplementation period.