synthesis. Studies have reported that it takes about four weeks after cessation of creatine
supplementation for muscle creatine (Vandenberghe et al., 1997) and phosphocreatine (Febbraio et
al., 1995) content to return to normal. It is unclear whether muscle the content falls below normal
thereafter. Although more research is needed, there is no evidence that creatine supplementation
causes a long-term suppression of creatine synthesis when supplementation stops (Balsom,
Soderlund & Ekblom, 1994; Hultman et al., 1996).
Does creatine supplementation have undiscovered long-term side effects? Trials lasting more than a
year have not been performed, but creatine has been used as a nutritional supplement for over 10
years. Although long-term side effects cannot discounted, no significant short-term side effects other
than weight gain have been reported. In addition, I am not aware of any significant medical
complications that have been linked to creatine supplementation. Furthermore, creatine and
phosphocreatine have been used medically to reduce muscle wasting after surgery and to improve
heart function and exercise capacity in people with ischemic heart disease (Pauletto & Strumia,
1996; Gordon et al., 1995). Creatine supplementation may even reduce the risk of heart disease by
improving blood lipids (Earnest, Almada & Mitchell, 1996; Kreider et al., 1998). On the basis of the
available research, I consider creatine supplementation to be a medically safe practice when taken at
dosages described in the literature.
Determining whether creatine supplementation has any short- or long-term side effects is an area
receiving additional research attention. If there are side effects from long-term creatine
supplementation, an important issue will be the liability of coaches, trainers, universities, and athletic
governing bodies who provide creatine to their athletes. Anyone advising athletes to take creatine
should make it clear that side effects from long-term use cannot be completely ruled out, and that the
athletes do not have to take the supplements. It would be wise to have a formal policy for dosages
to reduce the chances of athletes taking excessive amounts.
Ethics
Creatine supplementation is not banned, but is a nutritional practice that enhances performance
nevertheless unethical? Anyone pondering this question should consider that creatine
supplementation is a practice similar to carbohydrate loading, which is well accepted. Some are also
concerned that creatine supplementation could cause a carryover effect, whereby athletes who have
learned to take creatine are more likely to use dangerous or banned substances. Proper education
among athletes, coaches, and trainers regarding acceptable and unacceptable nutritional practices is
probably the best way to reduce any carryover.
How to Use Creatine
A typical loading regime for a 70-kg athlete is a 5-g dose four times a day for a week. Thereafter the
dose can be reduced to 2 to 5 g per day in order to maintain elevated creatine content. This
supplementation protocol will increase intramuscular creatine and phosphocreatine content and
enhance high intensity exercise performance. There is now some evidence that taking glucose (100
g) with the creatine (5 to 7 g) increases the uptake of creatine into muscle (Green et al., 1996a;
Green et al., 1996b). Consequently, I recommend that athletes take creatine with carbohydrate (e.g.
with grape juice) or ingest commercially available creatine supplements that combine creatine with
glucose. For athletes wanting to promote additional gains in lean body mass, I recommend 15 to 25
g per day for 1 to 3 months. Although many athletes cycle on or off creatine, no study has
determined whether this practice promotes greater gains in fat free mass or performance than
continuous use. More research is needed here.
Creatine supplements are good value. Creatine is now being sold for as little as US$30 per kg, or
about $0.60 per day when taking 20 g per day. Popular sports drinks are more expensive.