How the metabolic machinery of maximally exercising muscle fails.

Keywords: mitochondria; muscle metabolism; nuclear magnetic resonance; 31P MRS EN mitochondria muscle metabolism nuclear magnetic resonance 31P MRS 1797 1798 2 05/18/20 20200515 NES 200515 Four decades after it was first applied to skeletal muscle, phosphorus magnetic resonance spectroscopy ( SP 31 sp P MRS) remains a valuable noninvasive window into metabolism I in vivo i . Bartlett I et al i . did not choose a multimodal approach, but used one of the most conceptually straightforward SP 31 sp P MRS analyses: the initial post-exercise PCr resynthesis rate as a measure of the end-exercise suprabasal oxidative ATP synthesis rate. SP 31 sp P MRS offers a simple way to address ATP cost: the initial PCr depletion rate measures total ATP turnover at the start of exercise, but this obviously cannot be repeated to generate a time-course. [Extracted from the article]