title: Using a logarithmic regression to identify the heart-rate threshold in cyclists.
abstract: The purpose of this study was to establish an objective method for identifying the heart-rate threshold (HRT) in cyclists. Fifty-six male cyclists were tested on a cycle ergometer to volitional fatigue. Identification of the HRT used a heart-rate increase above a logarithmic regression line of best fit, coupled with the crossover of a linear regression line of best fit. The measures of Vco(2) and blood lactate for ventilatory threshold (VT) and lactate threshold (HLaT), respectively, were used as criterion measures to validate the HRT. Comparison of HRT with VT and HLaT showed significant associations (r = 0.98). Statistical variance between HRT, VT, and HLaT indicated no difference. From these findings, the logarithmic regression method provides an objective means to determine the HRT. Through this method, cyclists may obtain information for establishing accurate training levels and protocols.
authors.affiliation: Louisiana Tech University, Department of Health and Exercise Sciences, Ruston, Louisiana 71272, USA. frank.wyatt@mwsu.edu
authors.forename: Frank
authors.initials: F
authors.lastname: Wyatt
authors.forename: Selena
authors.initials: S
authors.lastname: Godoy
authors.forename: Lance
authors.initials: L
authors.lastname: Autrey
authors.forename: Jason
authors.initials: J
authors.lastname: McCarthy
authors.forename: James
authors.initials: J
authors.lastname: Heimdal
mesh_terms: D001642:Bicycling / Q000502:physiology*; D016552:Ergometry; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology
chemical_list: D019344:Lactic Acid