Sille Vaiksaar will defend her thesis "Effect of menstrual cycle phase and oral contraceptive use on selected performance parameters in female rowers" on 29 August 2012 at 10 a.m. in Senate's Hall of the University of Tartu, applying for the degree of Doctor of Philosophy in exercise and sport sciences.
Supervisor: Professor Jaak Jürimäe.
Opponent: Professor Arvydas Stasiulis (Lithuanian Academy of Physical Education).
Women train and compete in different sporting events during all stages of menstrual cycle. Female hormones estrogen and progesterone fluctuate predictably across the menstrual cycle in normally cycling eumenorrheic women. It has been reported that estrogen may promote endurance performance by altering carbohydrate and lipid metabolism while progesterone often acts antagonistically. Studies investigating menstrual cycle effects on endurance performance have yielded contradicting results. Few researchers have investigated the effect of a menstrual cycle phase and oral contraceptive (OC) pill cycle on performance and training parameters in trained female rowers. Accordingly, it is apparent that OC use is becoming more prevalent in female athletes. The use of oral contraceptives may provide a more stable environment to evaluate the possible effect of reproductive hormones on physiological variables and exercise performance in women. While synthetic menstrual cycle also contains two phases, it is important to investigate whether changes in hormone concentration levels are affecting athletic performance or not.
The aim of the present study was to investigate the effects of the normal menstrual cycle and the synthetic menstrual cycle of oral contraceptive users on aerobic performance in female rowers. The rowers performed two identical tests in two different menstrual cycle phases. Normally menstruating female rowers and female rowers taking OC pills need not consider the phase of menstrual cycle for optimizing their aerobic performance during testing and everyday training.