The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels
Mike Spillane,1 Ryan Schoch,4 Matt Cooke,1 Travis Harvey,5 Mike Greenwood,1 Richard Kreider,3 and Darryn S Willoughbycorresponding author1,2
1Department of Health, Human Performance and Recreation, Baylor University, Box 97313, Waco, TX 76798, USA
2Institute for Biomedical Science, Baylor University, Waco, TX 87898, USA
3Department of Health and Kinesiology, Texas A&M University, College Station, TX 78743, USA
4Interdepartmental Nutrition Program, Purdue University, West Lafayette, IN 47907, USA
5Department of Physical Education, United States Military Academy, West Point, NY 10096, USA
corresponding authorCorresponding author.
Mike Spillane:
micheilspillane@hotmail.com; Ryan Schoch:
rschoch@purdue.edu; Matt Cooke:
matt_cooke@baylor.edu; Travis Harvey:
Travis.Harvey@usma.edu; Mike Greenwood:
mike_greenwood@baylor.edu; Richard Kreider:
rkreider@hlkn.tamu.edu; Darryn S Willoughby:
darryn_willoughby@baylor.edu
Received December 29, 2008; Accepted February 19, 2009.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (
Creative Commons — Attribution 2.0 Generic), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
* Other Sections▼
o Abstract
o Introduction
o Methods
o Results
o Discussion
o Conclusion
o Competing interests
o Authors' contributions
o References
Abstract
Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester is alleged to increase creatine bio-availability. This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males. In a double-blind manner, 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 (approximately 20 g/day) for five days followed by ingestion at 0.075 g/kg fat free mass (approximately 5 g/day) for 42 days. Results showed significantly higher serum creatine concentrations in PLA (p = 0.007) and CRT (p = 0.005) compared to CEE. Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001) and increased at days 6, 27, and 48. Total muscle creatine content was significantly higher in CRT (p = 0.026) and CEE (p = 0.041) compared to PLA, with no differences between CRT and CEE. Significant changes over time were observed for body composition, body water, muscle strength and power variables, but no significant differences were observed between groups. In conclusion, 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.
Non-enzymatic hydrolysis of creatine ethyl ester.
Katseres NS, Reading DW, Shayya L, Dicesare JC, Purser GH.
Department of Chemistry and Biochemistry, The University of Tulsa, 800 Tucker Drive, Tulsa, OK 74014, USA.
Abstract
The rate of the non-enzymatic hydrolysis of creatine ethyl ester (CEE) was studied at 37 degrees C over the pH range of 1.6-7.0 using (1)H NMR. The ester can be present in solution in three forms: the unprotonated form (CEE), the monoprotonated form (HCEE(+)), and the diprotonated form (H(2)CEE(2+)). The values of pK(a1) and pK(a2) of H(2)CEE(2+) were found to be 2.30 and 5.25, respectively. The rate law is found to be Rate=-dCCEE/dt=k++[H2CEE2+][OH-]+k+[HCEE+][OH-]+k0[CEE][OH-] where the rate constants k(++), k(+), and k(0) are (3.9+/-0.2)x10(6)L mol(-1)s(-1), (3.3+/-0.5)x10(4)L mol(-1)s(-1), and (4.9+/-0.3)x10(4)L mol(-1)s(-1), respectively. Calculations performed at the density functional theory level support the hypothesis that the similarity in the values of k(+) and k(0) results from intramolecular hydrogen bonding that plays a crucial role. This study indicates that the half-life of CEE in blood is on the order of one minute, suggesting that CEE may hydrolyze too quickly to reach muscle cells in its ester form.
