title: Adenosine triphosphate production rates, metabolic economy calculations, pH, phosphomonoesters, phosphodiesters, and force output during short-duration maximal isometric plantar flexion exercises and repeated maximal isometric plantar flexion exercises.
abstract: Measurements of adenosine triphosphate (ATP) production rates, metabolic economy, intracellular pH, phosphodiesters, and phosphomonoesters along with the force output were used to study 90-s maximum voluntary contractions and two new exercise protocols (20-10 and 30-16 exercises). The 20-10 exercise consisted of thirty-one 20-s maximal voluntary contractions separated by 10-s rest periods. The 30-16 exercise consisted of twenty 30-s maximal voluntary contractions separated by 16-s rest periods. There were no differences in ATP production rates, metabolic economy, intracellular pH, or force output between the 20-10 and 30-16 exercises. The 20-10 exercises accumulated more phosphomonoesters than the 30-16 exercises. These increases in phosphomonoesters may be attributed to increased accumulations of glucose-6-phosphate and/or inosine monophosphate. The increased perception of effort reported during and after the 20-10 exercises was not present during the 30-16 or 90-s exercises. This increased perception of effort may be related to increases in lactate, glucose-6-phosphate, inosine monophosphate, and/or NH3.
authors.affiliation: Department of Biochemistry and Molecular Biology, Wright State University, Kettering, Ohio, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Newcomer
authors.forename: M D
authors.initials: MD
authors.lastname: Boska
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D015444:Exercise; D005260:Female; D005528:Foot / Q000502:physiology*; D019298:Glucose-6-Phosphate / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007291:Inosine Monophosphate / Q000378:metabolism; D007537:Isometric Contraction; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology; D009132:Muscles / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism*; D012649:Self Concept; D013997:Time Factors
chemical_list: D009943:Organophosphorus Compounds; D007291:Inosine Monophosphate; D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate