Part 1 of this article, we examined the performance-enhancing effects of caffeine supplementation on endurance performance in athletes.  Part 2 will be focused on another commonly used dietary supplement, creatine. 

In the previous article, the point was made that, in order to recognize supplements that are potentially effective and relevant to soccer, three specific criteria must be met:

Does the supplement work? (it must affect some physical, physiological, psychological, or other health factor that has an influence on performance in soccer)

Is the supplement safe? (it must not cause any adverse health effects)

Is the supplement banned? (it must not contain any substance which is named in a banned substance list, or which may result in a positive doping test)

Does Creatine Work?

Creatine is a guadinine (amino acid) compound, naturally occurring in meat and fish.  Creatine is stored in the body in two forms:  free creatine, stored in the blood, accounts for approximately 40% of the total creatine in the body.  A modified molecule of creatine, called creatine phosphate, is the body’s second source of creatine, and accounts for the remaining 60%. 

The primary energy source of short-duration, high intensity exercise, creatine phosphate is crucial for the performance of sports that involve these types of movements, including soccer.  When such exercises are performed (for example, several short sprints done in a short amount of time) the body’s natural supply of creatine phosphate is depleted, which can effect subsequent repeated sprint performance. 

The most commonly used dietary supplement is a form of creatine called creatine monohydrate, which is sold in powder form.  For athletes, including soccer players, creatine supplements will elicit two different performance-enhancing effects:

• an increased ability to perform short sprints

• increase in the gains in muscle size and strength that typically accompany resistance training

For the purpose of this article, I will be focusing on improvement number one, as this has more relevance to soccer players. The increase in ability to perform short sprints occurs as a result of increasing the body’s stores of creatine phosphate inside exercising muscles. The more creatine stored in the muscle, the greater the anaerobic capacity or, more specifically, the greater the exercising time to exhaustion during high intensity, short duration running (sprinting).

There have been several studies conducted on athletes (including soccer players) which have demonstrated this training effect.  Although soccer is an aerobic sport, there are moments during soccer games, called repeated sprint sequences (RSS’s), where players will perform several short sprints without a lot of recovery in between.  At the elite male professional level, players typically perform between 5 and 10 RSS’s per game.  Increased free creatine and intramuscular creatine will help soccer players to improve their performances of RSS’s. 

Furthermore, the demand to replenish creatine phosphate in the muscles, in order to allow athletes to continue to run/sprint fast throughout the game, is constant, so having more creatine available will speed up the replenishment of creatine phosphate as it is used, and thus allow players to maintain high intensity running ability longer throughout a game.  

Is Creatine Safe?

Typically, the dose of creatine administered is approximately 20grams per day, for an initial “loading period” of 5-7 days.  After this period, doses will typically be decreased during a “maintenance phase”, to between 5-8 grams per day, over the subsequent weeks and/or months. 

Because creatine monohydrate supplementation has become widespread in both athletic, as well as general populations, several long-term studies have been done to examine the effects, and potential negative side-effects, of the supplement. 

To date, there have been no negative side effects reported from creatine supplementation done following the aforementioned guidelines (5-7 day loading phase with 20 grams per day followed by 14-90 days of maintenance with 5-8 grams per day), other than some gastrointestinal distress when more than 10 grams per day are ingested (Ostojic et.Al., 2008). These doses are easily obtainable by ingesting creatine monohydrate in powder form, which is readily available over-the-counter at drug and health food stores.  Thus, creatine is both safe, easy to find and use, and effective in improving performance.

Is Creatine Banned?

To date, both the World Anti-Doping Agency (WADA), the International Olympic Committee (IOC), as well as the NCAA and CIS, do not list creatine as a banned substance.  Consumption of creatine by athletes is legal.  Below is a chart detailing the supplementation guidelines described above:

Richard Bucciarelli is the President of Soccer Fitness Inc., and Fitness Coach for the Canadian National Women’s U17 team, which will be travelling to Guatemala in May 2012 for the CONCACAF qualification tournament for the FIFA U17 Women’s World Cup. For more information about Richard and Soccer Fitness visit www.soccerfitness.ca