title: Effect of energy restriction on muscle function and calcium stimulated protease activity in recreationally active women.
abstract: The purpose of this study was to investigate whether changes in substrate oxidation that are caused by energy restriction influenced muscle function and skeletal muscle calcium stimulated protease activity in female athletes. Endurance athletes were randomly assigned to maintenance energy (100% kcal) or energy restricted (75% kcal) diet treatment groups for 14 days while maintaining regular activity. Body weight significantly decreased in the 75% diet group (-1.7 +/- 0.3 kg; p < .05), while fat oxidation increased (p < .05). Minimal changes in quadriceps function (assessed using the Kin/Com isokinetic dynamometer) were observed following diet treatment, except selected loss of muscle function in the 75% diet group at a movement velocity of 120 deg/s. These results suggest that increased fat oxidation that is induced by an acute energy restriction does not promote loss of general muscle function and activation of calcium-sensitive muscle proteases.
authors.affiliation: Department of Agricultural Food and Nutritional Science, University of Alberta, Edmonton, Canada.
authors.forename: S C
authors.initials: SC
authors.lastname: Parkes
authors.forename: A N
authors.initials: AN
authors.lastname: Belcastro
authors.forename: L J
authors.initials: LJ
authors.lastname: McCargar
authors.forename: D
authors.initials: D
authors.lastname: McKenzie
mesh_terms: D000328:Adult; D001835:Body Weight / Q000502:physiology; D002118:Calcium / Q000502:physiology*; D002154:Calpain / Q000378:metabolism; D004032:Diet; D010450:Endopeptidases / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D010084:Oxidation-Reduction; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion; D013177:Sports
chemical_list: D010450:Endopeptidases; D002154:Calpain; D002118:Calcium