title: Thyroid hormones may influence the slow component of VO(2) in professional cyclists.
abstract: We analyzed the relationship between the plasma concentrations of several hormones (testosterone [T], follicle-stimulating [FSH] and luteinizing hormone [LH], cortisol [C], 3,5,3'-triiodothyronine [T(3)], thyroxine [T(4)], and thyrotrophin [TSH]) and the magnitude of the VO(2) slow component (Delta VO(2)) in a group of nine professional road cyclists (26+/-2 years). The resting levels of the aforementioned hormones were determined before the subjects performed a 20-min cycle ergometer test at approximately 80% of VO(2 max) (or approximately 400 W). Plasma concentrations of T(3) and T(4) were inversely correlated (p<0.05) with Delta VO(2) (r=-0.72 and rr=-0.66, respectively), suggesting, at least partly, and association between thyroid basal function and the VO(2) slow component of euthyroid elite endurance athletes during constant-load intense exercise.
authors.affiliation: Departamento de Ciencias Morfológicas y Fisiología, Universidad Europea de Madrid, Spain. alejandro.lucia@mrfs.cisa.uem.es
authors.forename: A
authors.initials: A
authors.lastname: Lucía
authors.forename: J
authors.initials: J
authors.lastname: Hoyos
authors.forename: M
authors.initials: M
authors.lastname: Pérez
authors.forename: J L
authors.initials: JL
authors.lastname: Chicharro
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D004576:Electromyography; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007700:Kinetics; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D013739:Testosterone / Q000097:blood / Q000494:pharmacology; D013963:Thyroid Hormones / Q000097:blood / Q000494:pharmacology*
chemical_list: D013963:Thyroid Hormones; D013739:Testosterone; D006854:Hydrocortisone