Reproducibility of Muscle Metabolism Parameters in Children Determined by 31P Spectroscopy
Fulford J, Armstrong N, Welford D, Barker A, Welsman J
University of Exeter
The study examined the reproducibility of 31P-MRS muscle energetic measurements during incremental exhaustive exercise tests in children. Three progressive tests to volitional exhaustion (end exercise) were undertaken and dynamic changes in muscle phosphocreatine (PCr), inorganic phosphate (Pi) and intracellular pH determined. From plots of Pi/PCr and pH against work rate, intracellular thresholds (ITs) were determined. Coefficients of variation (CV) for Pi/PCr and pH ITs were 9.2 % and 9.9 %. End exercise CVs for pH and Pi/PCr were 1.0 % and 50.9 %, respectively. Thus, when examining exercise characteristics from children, IT values provide greater reliability than those obtained from end exercise.