title: No effect of menstrual cycle phase on fuel oxidation during exercise in rowers.
abstract: The aim of this investigation was to examine the effects of menstrual cycle phase on substrate oxidation and lactate concentration during exercise. Eleven eumenorrheic female rowers (18.4 ± 1.9 years; 172.0 ± 4.0 cm; 67.2 ± 8.4 kg; 27.7 ± 4.8% body fat) completed 1 h rowing ergometer exercise at 70% of maximal oxygen consumption (VO(2max)) during two different phases of the menstrual cycle: the follicular phase (FP) and the luteal phase (LP). Resting and exercise measurements of the whole body energy expenditure, oxygen consumption (VO(2)), respiratory exchange ratio (RER), substrate oxidation and lactate blood levels were made. Energy expenditure, VO(2) and heart rate during the 1-h exercise were not significantly different (P > 0.05) among menstrual cycle phases. Resting RER and RER during the entire 1 h exercise period were not significantly different among menstrual cycle phases. There was an increase (P < 0.05) in RER in the transition between rest and exercise and a further increase in RER occurred after the first 30 min of exercise at both menstrual cycle phases. Blood lactate concentrations significantly increased in the transition between rest and exercise and remained relatively constant during the whole 1 h of exercise in both menstrual cycle phases. No menstrual cycle phase effect (P > 0.05) was observed for blood lactate concentrations. In conclusion, our results demonstrated no effect of menstrual cycle phase on substrate oxidation and blood lactate concentration during rowing exercise at 70% of VO(2max) in athletes. Normally menstruating female rowers should not be concerned about their menstrual cycle phase with regard to substrate oxidation in everyday training.
authors.affiliation: Institute of Sport Pedagogy and Coaching Sciences, Centre of Behavioral, Social and Health Sciences, University of Tartu, 18. Ülikooli St., 50090 Tartu, 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: D000293:Adolescent; D001132:Arm / Q000502:physiology*; D004040:Dietary Carbohydrates / Q000378:metabolism; D004435:Eating / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000378:metabolism / Q000502:physiology*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology*; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates