 Research articleThe effects of creatine pyruvate and creatine citrate on performance during high intensity exerciseRalf Jäger1 , Jan Metzger2 , Karin Lautmann2 , Vladimir Shushakov2 , Martin Purpura1 , Kurt-Reiner Geiss3 and Norbert Maassen2  1Increnovo LLC, 2138 E Lafayette Pl, Milwaukee, WI 53202, USA 2Department of Sports Physiology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany 3ISME, Weingartenstr. 2, D-64546 Mörfelden-Walldorf, Germany author email corresponding author email
Journal of the International Society of Sports Nutrition 2008,
5:4doi:10.1186/1550-2783-5-4
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| Published: |
13 February 2008 |
Abstract
Background
A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr) and creatine citrate (Cr-Cit) supplementation on exercise performance in healthy young athletes.
Methods
Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest) and after (posttest) 28 days of Cr-Pyr (5 g/d, n = 16), Cr-Cit (5 g/d, n = 16) or placebo (pla, 5 g/d, n = 17) intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods.
Results
Cr-Pyr (p < 0.001) and Cr-Cit (p < 0.01) significantly increased mean power over all intervals. Cr-Cit increased force during the first and second interval (p < 0.01) compared to placebo. The effect of Cr-Cit on force decreased over time and the improvement was not significant at the sixth and ninth interval, whereas Cr-Pyr significantly increased force during all intervals (p < 0.001). Cr-Pyr (p < 0.001) and Cr-Cit (p < 0.01) resulted in an increase in contraction velocity, whereas only Cr-Pyr intake significantly (p < 0.01) increased relaxation velocity. Oxygen consumption measured during rest periods significantly increased with Cr-Pyr (p < 0.05), whereas Cr-Cit and placebo intake did not result in significant improvements.
Conclusion
It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism. |