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Effects of creatine supplementation on the energy cost of muscle contraction: a 31P-MRS study.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Smith, Scott A. Montain, Scott Matott, R. P. Zientara, Gary P. Jolesz, Ferenc A. Fielding, Roger A. |
| Copyright Year | 1999 |
| Abstract | Five women and 3 men (29.8 +/- 1.4 yr) performed dynamic knee-extension exercise inside a magnetic resonance system (means +/- SE). Two trials were performed 7-14 days apart, consisting of a 4- to 5-min exhaustive exercise bout. To determine quadriceps cost of contraction, brief static and dynamic contractions were performed pre- and postexercise. (31)P spectra were used to determine pH and relative concentrations of P(i), phosphocreatine (PCr), and betaATP. Subjects consumed 0.3 g. kg(-1). day(-1) of a placebo (trial 1) or creatine (trial 2) for 5 days before each trial. After creatine supplementation, resting DeltaPCr increased from 40.7 +/- 1.8 to 46. 6 +/- 1.1 mmol/kg (P = 0.04) and PCr during exercise declined from -29.6 +/- 2.4 to -34.1 +/- 2.8 mmol/kg (P = 0.02). Muscle static (DeltaATP/N) and dynamic (DeltaATP/J) costs of contraction were unaffected by creatine supplementation as well as were ATP, P(i), pH, PCr resynthesis rate, and muscle strength and endurance. DeltaATP/J and DeltaATP/N were greatest at the onset of the exercise protocol (P < 0.01). In summary, creatine supplementation increased muscle PCr concentration, which did not affect muscle ATP cost of contraction. |
| Starting Page | 39 |
| Ending Page | 48 |
| Page Count | 10 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://jap.physiology.org/content/jap/87/1/116.full.pdf |
| PubMed reference number | 10409565v1 |
| Volume Number | 87 |
| Issue Number | 1 |
| Journal | Journal of applied physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Adenosine Triphosphate Contain (action) Creatine Email Excitation Kinetics (discipline) Mandibular right second molar tooth Millimole per Kilogram Muscle Contraction Muscle Fibers Myalgia Phosphocreatine Polymerase Chain Reaction Reprint Rest Science Status Epilepticus Structure of quadriceps femoris muscle Universities phosphagen metabolic process |
| Content Type | Text |
| Resource Type | Article |
