title: Phase of oral contraceptive cycle and endurance capacity of rowers.
abstract: Eight female rowers (M age = 21.0 yr., SD = 2.8), using a monophasic oral-contraceptive pill, performed a 1-hr. rowing ergometer test (intensity: 70% VO2max) during the active-pill and non active-pill phases of the oral contraceptive cycle. No significant differences were found in mean energy expenditure, oxygen consumption, respiratory exchange ratio, and heart rate during the endurance test at the two phases of the oral contraceptive cycle. Mean energy expenditure rate, carbohydrate energy expenditure, lipid energy expenditure, and blood lactate during the test were not statistically significantly different among the cycle phases. In conclusion, there was no observed difference in substrate oxidation and blood lactate level during endurance rowing at different phases of the oral contraceptive cycle in these endurance-trained rowers. Endurance-trained female athletes on oral contraceptives should not worry about the possible differences in substrate oxidation during everyday training at different phases of the oral contraceptive cycle.
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, University of Tartu, 18 Ulikooli Street, Tartu 50090, Estonia.
authors.forename: Sille
authors.initials: S
authors.lastname: Vaiksaar
authors.forename: Jaak
authors.initials: J
authors.lastname: Jürimäe
authors.forename: Jarek
authors.initials: J
authors.lastname: Mäestu
authors.forename: Priit
authors.initials: P
authors.lastname: Purge
authors.forename: Svetlana
authors.initials: S
authors.lastname: Kalytka
authors.forename: Larissa
authors.initials: L
authors.lastname: Shakhlina
authors.forename: Toivo
authors.initials: T
authors.lastname: Jürimäe
mesh_terms: D001823:Body Composition / Q000187:drug effects; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004734:Energy Metabolism / Q000187:drug effects; D016552:Ergometry / Q000187:drug effects; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects; D009652:Norpregnenes / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood; D010807:Physical Endurance / Q000187:drug effects*; D013177:Sports; D055815:Young Adult
chemical_list: D003277:Contraceptives, Oral, Combined; D009652:Norpregnenes; C033273:Gestodene; D004997:Ethinyl Estradiol; D010100:Oxygen