Author(s): SMITH BISGAARD, M., HANSEN, M. , Institution: AARHUS UNIVERSITY , Country: DENMARK, Abstract-ID: 1057

INTRODUCTION:
Combined oral contraceptive pills (OCP) containing synthetic estradiol and one type of progestin are used by 27 to 41% of female athletes in various European countries [1-3]. Previous research indicates a potential slightly reduced exercise performance in OCP users compared to non-OCP users [4]. However, the acute effect of OCP intake on athletic performance has not been studied.
During OCP use, the endogenous levels of sex hormones are downregulated to fairly constant low levels. However, serum concentrations of the exogenous sex hormones from the OCP peak between one and two hours after pill intake [5, 6], but already after eight hours, the concentrations of exogenous hormones have declined to low levels. Whether these fluctuations affect exercise performance remains undetermined.
We aimed to investigate a potential acute effect of OCP intake on strength, power, and endurance performance in trained females.

METHODS:
Twenty-two trained young females using monophasic 2nd generation OCPs were tested in a randomized cross-over controlled study. Participants completed a physical performance test protocol twice during the active OCP period. In randomized order, the participants completed the tests one hour after intake of the OCP and 24 hours after intake of the OCP respectively. The physical tests included a balance stand test, a muscular endurance push-up test, an agility test, and measurements of isometric handgrip strength, countermovement jump height, flexibility and a maximal oxygen uptake bike test. In addition, a questionnaire about psychological wellbeing was completed before testing. Time of the day, energy intake and exercise 24 hours preceding the tests was standardized and participants were familiarized with the tests beforehand. Serum and saliva hormone analysis ensured OCP compliance and exact levels of exogenous hormones at the time of testing.

RESULTS:
No significant difference in exercise performance parameters was observed between the test days; OCP intake one hour before testing versus 24 hours before testing.

CONCLUSION:
Collectively, timing of OCP intake in young, trained females did not significantly affect exercise performance parameters. This study indicates, that female athletes using OCPs and pursuing to optimize their physical performance, can omit concerns on when to take their OCP.

References
1. Martin, D., et al., 2018, Int J Sports Physiol Perform.
2. Oxfeldt, M., et al., 2020, Int J Sports Physiol Perform.
3. Ekenros, L., et al., 2022, Frontiers Media S.A.
4. Elliott-Sale, K.J., et al., 2020, Springer.
5. Jung-Hoffmann, C., et al., 1991, Karger Publishers.
6. Stanczyk, F.Z., 2002, Springer. p. 211-224.