a new method for non-invasive estimation of human muscle fiber type composition一种新的非侵入性方法估计人类肌肉纤维类型组成.pdfVIP

A New Method for Non-Invasive Estimation of Human Muscle Fiber Type Composition 1 1 2 3 4 1 Audrey Baguet , Inge Everaert , Peter Hespel , Mirko Petrovic , Eric Achten , Wim Derave * 1 Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium, 2 Research Center for Exercise and Health, K.U. Leuven, Leuven, Belgium, 3 Department of Internal Medicine, Ghent University, Ghent, Belgium, 4 Department of Radiology, Ghent Institute for Functional and Metabolic Imaging (GIfMI), Ghent University, Ghent, Belgium Abstract Background: It has been established that excellence in sports with short and long exercise duration requires a high proportion of fast-twitch (FT) or type-II fibers and slow-twitch (ST) or type-I fibers, respectively. Until today, the muscle biopsy method is still accepted as gold standard to measure muscle fiber type composition. Because of its invasive nature and high sampling variance, it would be useful to develop a non-invasive alternative. Methodology: Eighty-three control subjects, 15 talented young track-and-field athletes, 51 elite athletes and 14 ex-athletes volunteered to participate in the current study. The carnosine content of all 163 subjects was measured in the gastrocnemius muscle by proton magnetic resonance spectroscopy (1H-MRS). Muscle biopsies for fiber typing were taken from 12 untrained males. Principal Findings: A significant positive correlation was found between muscle carnosine, measured by 1H-MRS, and percentage area occupied by type II fibers. Explosive athletes had ,30% higher carnosine levels compared to a reference population, whereas it was ,20% lower than normal in typical endurance athletes. Si