Creatine supplementation--part II: in vivo magnetic resonance spectroscopy.
Med Sci Sports Exerc
; 31(12): 1770-7, 1999 Dec.
Article
en En
| MEDLINE
| ID: mdl-10613427
ABSTRACT
PURPOSE:
Our purpose was to study effects of creatine (Cr) supplementation on muscle metabolites noninvasively by means of magnetic resonance spectroscopy (MRS) before and after supplementation with Cr or placebo.METHODS:
1H-MRS was used in a comprehensive, double-blind, cross-over study in 10 volunteers to measure Cr in m. tibialis anterior and m. rectus femoris at rest. PCr/ATP was observed in m. quadriceps femoris by 31P-MRS at rest and after exercise.RESULTS:
A significant increase in total Cr was observed with Cr intake in m. tibialis anterior (+9.6 +/- 1.7%, P = 0.001) and in m. rectus femoris (+18.0 +/- 1.8%, P < 0.001). PCr/ATP showed a significant increase (+23.9 +/- 2.3%, P < 0.001) in m. quadriceps femoris at rest with Cr supplementation. Post-Cr supplementation recovery rates from exercise were significantly lower (k = 0.029 s(-1), P < 0.01) compared with postplacebo consumption (k = 0.034 s(-1)) and presupplementation (k = 0.037 s(-1)). However, higher levels of PCr/ATP at rest compensate for this reduction of the recovery rate after Cr supplementation. The increase of PCr/ATP determined by 31P-MRS correlates with the increase of Cr observed by 1H-MRS (r = 0.824, P < 0.001).CONCLUSION:
Noninvasive observation of Cr and PCr after Cr supplementation shows an increase in a muscle specific manner. Higher preexercise levels of PCr/ATP at rest compensate for significantly slower recovery rates of PCr/ATP after Cr supplementation.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Deportes
/
Creatina
/
Músculos
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Humans
/
Male
Idioma:
En
Revista:
Med Sci Sports Exerc
Año:
1999
Tipo del documento:
Article
País de afiliación:
Suiza