The effects of streneous exercise on intramuscular magnesium concentrations and muscle metabolism
Turner, Tiffany Nicole
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3131P magnetic resonance spectroscopy (P MRS) has been used to measure muscle oxidative metabolism and intramuscular magnesium concentrations. The purpose of this study was to evaluate our ability to make these measurements in the quadriceps muscles of twelve males before and after strenuous walking. In vivo phosphocreatine (PCr) recovery kinetics was measured after 30-39 second bouts of isometric exercise. PCr recovery averaged 39 seconds and had an ICC of 0.819. The mean end exercise PCr was 47.6% and the mean end exercise pH was 6.97. Intramuscular magnesium concentrations averaged 0.388 and had a COV% between days of 7.91. Strenuous walking did not produce significant alterations in either PCr recovery kinetics or intracellular magnesium levels. In conclusion, despite excellent signal to noise values, PCr recovery after exercise has relatively low reproducibility and prior exercise is unlikely to alter measurements of resting metabolites or muscle metabolism.