Aim of the study:Hundreds of clinical trials have been conducted with creatine, with most of them (but by far not all of them) supporting the assumption that creatine supports muscle growth. Almost all of those studies have been conducted with creatine monohydrate.
Various claims have been made concerning other forms of creatine, mostly by their producers of patent holders. Hardly any such claims have been supported by serious clinical trials. In this limited test we tried to compare the effects of various creatine forms and placebo.
Methods and products used:The muscle mass measurement by the IN BODY 230 certified device (producer BIOSPACE) took place every second Wednesday morning with control measurement 1 hour later.
It is sometimes argued that creatine causes water retention. Since the IN BODY device can distinguish between total muscle mass and other body issue, we were ignoring total body weight of our volunteers.
We were using commercially available creatine, we used microcrystalline cellulose as placebo.
We used the same dosage protocol for all forms of creatine and placebo:
0.3 g / kg of body weight / day for the first 6 days
0.03 g / kg of body weight / day for 40 days
Volunteers:Our volunteers were 35 males between 19 and 38 years of age. We divided the volunteers into 5 groups of seven volunteers: creatinemonohydrate (CM group), creatine ethyl ester (CEE group), creatine malate (CML), esterified creatine (EC) and control group (C group). The 7 volunteers in C group were given placebo. Our small test was double-blind, meaning that neither the volunteers nor our colleagues taking the measurements didn’t know who is using placebo and who is using creatine.
All of the volunteers were actively engaged in resistance training prior to the test and none of them was using any form of creatine at least 6 months before the test.
One of the volunteers in the EC group didn’t finish the study because of an illness unrelated to the study.
The average weight of our volunteers was 82.1 kg.
Duration of the study:The study lasted for 46 days.
Training, diet and additional supplementation:All participating volunteers were following the same resistance-training routine based on basic exercises (barbell squats, dumbbell press, v-bar pulldowns).
All the 5 groups of volunteers were on high-protein diet (about 1.5 g of protein per 1 kg of own body weight per day).
Two of our volunteers (one in group CM, the other in group CML) complained of irritation, sleep disorders and weakness. Our working hypothesis is that those symptoms were caused by overtraining and were not related to creatine intake.
Average muscle mass growth for the whole period:
Control group (placebo): 2.1 kg
Creatine monohydrate: 2.4 kg
Creatine ethyl ester: 2.2 kg
Esterified creatine: 2.5 kg
Creatine malate: 2.4 kg
The differences in muscle mass gain between the creatine groups and the control group were significant and can point to benefits of creatine intake for muscle mass growth, with the notable exception of creatine ethyl ester.
The difference between muscle mass gain of the CEE group and the control group were statistically insignificant and may mean that creatine ethyl ester is less effective muscle growth stimulant than other forms of creatine. This hypothesis would have to be confirmed by more clinical studies.