title: Effect of training on the calf muscle energy metabolism. A 31P-NMR study on four elite downhill skiers challenged with a standardized exercise protocol.
abstract: This study evaluates the effects of a 6 months' training period on the bioenergetics of the calf muscle of elite athletes by means of phosphorus-31 Nuclear Magnetic Resonance Spectroscopy (31P-NMR). Four downhill skiers, belonging to the Spanish National Team, performed a standardized exercise protocol using their right leg inside a wide-bore 2.35 Tesla magnet. The inorganic phosphate/phosphocreatine (Pi/PC) ratio and intracellular pH (pHi) were measured at steady-state during an exercise protocol composed of 5 work levels between 20% and 80% of the maximum voluntary contraction (MVC), before and after the training period. The measured values, which were markedly scattered at the beginning, regrouped after training. This was caused by a shift towards lower Pi/PC ratios and by a lower pHi acidification in three of the four subjects. This result suggests that 31P-NMR is a good tool to evaluate changes in the muscle aerobic capacity of athletes induced by training.
authors.affiliation: Institut de Résonance Magnétique en Biologie et Médecine (IRMBM), Université Joseph Fourier, Grenoble, France.
authors.forename: D
authors.initials: D
authors.lastname: Laurent
authors.forename: G
authors.initials: G
authors.lastname: Bernús
authors.forename: J
authors.initials: J
authors.lastname: Alonso
authors.forename: J F
authors.initials: JF
authors.lastname: Lebas
authors.forename: C
authors.initials: C
authors.lastname: Arús
authors.forename: J M
authors.initials: JM
authors.lastname: González de Suso
authors.forename: A
authors.initials: A
authors.lastname: Rossi
mesh_terms: D000244:Adenosine Diphosphate / Q000032:analysis; D000293:Adolescent; D004734:Energy Metabolism; D006801:Humans; D007866:Leg; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009119:Muscle Contraction; D009132:Muscles / Q000378:metabolism*; D010807:Physical Endurance; D005082:Physical Exertion; D012865:Skiing
chemical_list: D000244:Adenosine Diphosphate