Should a Personal Trainer Recommend Creatine?
Clients often ask personal trainers what supplements or nutritional modifications might serve to provide the extra edge in attaining their goals. Misconstrued data and anecdotal based supportive claims are commonly encountered when an individual attempts to review supplement usefulness via the internet or other easy-access sources of information. Thus, the personal trainer should be aware that supplement companies are not regulated; company claims founded in “independent research” are not the same as peer reviewed research and the government does not require evidence of the proven efficacy or purity of any dietary supplements and herbs. To protect clients from the marketing of bogus supplement products a personal trainer must become aware of these facts and educate clients on the safety and proper use of them.
Of the numerous supplements used for ergogenic purposes, creatine is one of the most examined in peer reviewed literature and as such, its effectiveness is commonly inquired by personal training clients. In the form of phosphocreatine (PC), phosphorylated creatine has an essential role in immediate energy metabolism. It is naturally produced in the liver, kidneys, and pancreas from non-essential amino acids at a rate of 1-2 grams per day. It can also be obtained from dietary sources such as meat, poultry, and fish – Eskimos consume about 4-6 g from fish each day. Commonly sold in supplement form as creatine monohydrate, creatine supplements are used to enhance natural phosphocreatine stores in the body for improvement in high force actions. Studies have shown that supplementing 20-25 grams per day for 5-6 days (commonly recognized as a loading phase) can increase intramuscular creatine stores by approximately 20%. After the loading phase, it is common to maintain elevated creatine levels by consuming approximately 5 grams per day. Once supplementation discontinues, muscle creatine concentrations tend to return to baseline levels in about 4 weeks.
Personal trainers should be aware of the evidence regarding creatine supplementation published in periodicals from a variety of studies and clinical research:
- Creatine supplementation has been shown to provide improved short-term performance of intense exercise, and may aid athletes that rely primarily on the anaerobic energy systems such as power lifters, sprinters, and football players
- Creatine supplements taken for several weeks using both loading and non-loading phases have shown to improve PC storage
- Creatine supplementation has been shown to improve PC resynthesis during rest intervals
- Creatine supplementation has been shown to be associated with an increase in body mass, potentially due to increases in lean mass mainly via cellular fluid retention
- Creatine supplementation has not been shown to aid in long-duration endurance training or aerobic-dominant activities
- Creatine supplements have demonstrated ineffectiveness in some individuals (labeled nonresponders)
- Acute creatine supplementation has not been shown to enhance an acute bout of explosive/strength training (single dosage just prior to training session)
- Caffeine ingestion with creatine may negate or reduce the supplement’s ergogenic effects (equivocal data)
Although creatine supplementation has demonstrated levels of effectiveness for improved performance in short duration, high force activities, personal trainers should be aware of the potential side-effects of ingesting the supplement. In the case of creatine, anecdotal reports suggest side-effects including abdominal cramping and bloating, acute bouts of diarrhea, muscle cramping, stiffness, and strains. No controlled studies have documented any significant side-effects however, so a causal relationship between these effects and creatine supplementation has not been established. A newer form of creatine has become popular as it supposedly reduces the gastrointestinal distress associated with creatine monohydrate and was alleged to be more easily absorbed and therefore have greater bioavailabity. An article published in the Journal of the International Society of Sports Nutrition (Feb 2009) suggests otherwise. The 7-week study examined the combined effects of different forms of creatine supplementation with resistance training on measures of body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males. Using a double-blind method participants were randomly assigned to a maltodextrose placebo (PLA), creatine monohydrate (CRT), or creatine ethyl ester (CEE) group. The supplements were orally ingested at a dose of 0.30 g/kg fat-free body mass or approximately 20 g/day for a five day loading phase followed by ingestion at 0.075 g/kg fat free mass or approximately 5 g/day for 42 days. Following the treatments researchers concluded when compared to creatine monohydrate, creatine ethyl ester was not as effective at increasing serum and muscle creatine levels or in improving body composition, muscle mass, strength, and power. Therefore, the improvements in these variables can most likely be attributed to the training protocol itself, rather than the supplementation regimen.
Personal trainers should recognize supplementing creatine will only provide ergogenic aid for individuals with goals in-line with gaining strength, lean mass, or power. Since most clients are not performing near maximal lifts with long rest intervals it is likely not a key ingredient to personal training success. Likewise, the supplementation of creatine will not directly aid a client striving to enhance functional improvements, weight loss, improved aerobic performance or muscular endurance. Creatine happens to be one of the few supplements shown in numerous studies to be relatively safe and presumably effective for most individuals; but personal trainers should remain cautious when recommending ergogenic aids to clients (even if they are considered effective) as recommendations create potential liability.