caa a22 4500 467939969 CHVBK 20180406153009.0 cr unu---uuuuu 170328e20061201xx s 000 0 eng 10.1007/s00421-006-0302-x doi (NATIONALLICENCE)springer-10.1007/s00421-006-0302-x Reliability of 31P-magnetic resonance spectroscopy during an exhaustive incremental exercise test in children [Elektronische Daten] [Alan Barker, Joanne Welsman, Deborah Welford, Jonathan Fulford, Craig Williams, Neil Armstrong] This study examined the reliability of 31P-magnetic resonance spectroscopy (MRS) to measure parameters of muscle metabolic function in children. On separate days, 14 children (7 boys and 7 girls) completed three knee-extensor incremental tests to exhaustion inside a whole-body scanner (1.5T, Phillips). The dynamic changes in the ratio of inorganic phosphate to phosphocreatine (Pi/PCr) and intracellular muscle pH were resolved every 30s. Using plots of Pi/PCr and pH against power output (W), intracellular thresholds (ITs) for each variable were determined using both subjective and objective procedures. The ITPi/PCr and ITpH were observed subjectively in 93 and 81% of their respective plots, whereas the objective method identified the ITPi/PCr in 88% of the plots. The ITpH was undetectable using the objective method. End exercise (END) ENDPi/PCr, ENDpH, ITPi/PCr and ITpH were examined using typical error statistics expressed as a % coefficient of variation (CV) across all three exercise tests. The CVs for the power output at the subjectively determined ITPi/PCr and ITpH were 10.6 and 10.3%, respectively. Objective identification of the ITPi/PCr had a CV of 16.3%. CVs for ENDpH and ENDPi/PCr were 0.9 and 50.0%, respectively. MRS provides a valuable window into metabolic changes during exercise in children. During knee-extensor exercise to exhaustion, ENDpH and the subjectively determined ITPi/PCr and ITpH demonstrate good reliability and thus stable measures for the future study of developmental metabolism. However, the objectively determined ITPi/PCr and ENDPi/PCr displayed poor reliability. Springer-Verlag, 2006 MRS nationallicence Muscle metabolism nationallicence Intracellular threshold nationallicence Developmental nationallicence Barker Alan Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut Welsman Joanne Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut Welford Deborah Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut Fulford Jonathan Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut Williams Craig Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut Armstrong Neil Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut European Journal of Applied Physiology Springer-Verlag 98/6(2006-12-01), 556-565 1439-6319 98:6<556 2006 98 421 https://doi.org/10.1007/s00421-006-0302-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-006-0302-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Barker Alan Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut NATIONALLICENCE 700 1- Welsman Joanne Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut NATIONALLICENCE 700 1- Welford Deborah Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut NATIONALLICENCE 700 1- Fulford Jonathan Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut NATIONALLICENCE 700 1- Williams Craig Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut NATIONALLICENCE 700 1- Armstrong Neil Children's Health, Exercise Research Centre, St Luke's Campus, University of Exeter, EX1 2LU, Exeter, UK aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 98/6(2006-12-01), 556-565 1439-6319 98:6<556 2006 98 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer