Introductory text
The question of whether the menstrual cycle and hormonal contraceptives influence the physical performance of women is present in the everyday lives of many female athletes, but has so far been the subject of little scientific research. This Matura thesis investigated precisely this question: What effects do cycle phases have on physical performance, and do these effects differ between women with a natural cycle and those taking combined hormonal contraceptives (CHC)?
Women’s menstruation and its influence on physical performance is an important but largely unexplored topic that is still taboo in society. One example of this is an interview with American skier Mikaela Shiffrin in 2023, in which she described her difficulties after a race by saying: “I’m unfortunately in an unfortunate phase of my monthly cycle.” However, the Austrian commentator mistranslated this, prompting Shiffrin to use hashtags such as #normalizeperiods to break the taboo. Such situations motivated the author to learn more about menstruation and its influence on physical performance, especially in the context of hormonal contraceptives.
Method
In order to answer the research question, both quantitative and qualitative data were collected. Two data sets formed the basis of the study: One was a standardized 1000-meter rowing test, which was performed twice by ten women (five each with a natural cycle or CHC), each at different points in their cycle. Secondly, qualitative questionnaires were used to record subjective perceptions before and after the test. In addition, comprehensive background research was conducted on the physiology of the female cycle and the effects of hormonal contraception.
Ten participants were divided into two groups: Group 1 consisted of five women with natural menstrual cycles and Group 2 consisted of five women who used combined hormonal contraceptives. Both groups performed a 1000-meter rowing test twice: once during menstruation or withdrawal bleeding and once during the late follicular phase or one week after withdrawal bleeding. The participants also completed a questionnaire to document their subjective feelings before and after the test.
Results
The evaluation shows that although there were no statistically significant differences in the measured performance, clear trends can be identified: In both groups, participants felt less able to perform during menstruation or withdrawal bleeding and experienced pain or discomfort more frequently. During the late follicular phase or the week after the bleeding, on the other hand, they tended to perform better and described their physical sensation as more positive. However, there was no clear difference between the two groups – i.e. between naturally menstruating women and CHC users.
The quantitative data showed a tendency towards better performance in the late follicular phase or one week after withdrawal bleeding compared to menstruation or withdrawal bleeding. However, this difference was not statistically significant. The qualitative data showed that the participants felt less efficient and had more complaints during menstruation or withdrawal bleeding than in the late follicular phase or one week after withdrawal bleeding.
Conclusion
The study makes it clear that subjective factors such as motivation, well-being or pain can have a decisive influence on perceived performance – even if this is not always reflected in measurable results. Particularly in competitive sport, where the smallest differences can make the difference between winning and losing, it is therefore worth taking an individual look at your own cycle. For some athletes, hormonal contraception can be a way of avoiding discomfort during important competition phases – others prefer to rely on natural rhythms. The ideal solution is ultimately up to the individual.
The results of this study indicate that there is both a subjective and objective difference in physical performance between menstruation or withdrawal bleeding and the late follicular phase or one week after withdrawal bleeding. However, no significant difference in performance improvement was found between women with a natural cycle and women using combined hormonal contraceptives. For future studies, it would be useful to test competition-oriented female athletes with similar performance levels over a longer period of time in order to minimize possible biases due to a learning effect.
Andrina Ehrat
Matura class 2024
