With our menstrual cycles causing fluctuations in our hormones, we simply can’t manage our health in the way we are often taught. Sadly, much of our knowledge about fitness is based on the non-menstruating person, simply because the lack of menstruation and the resulting hormone fluctuations in a person creates less variables in research studies. However, we are here to give you a brief summary of the research that we are aware of that is assessing the link between our cycles and our health and performance.
One of the main causes of why we are different is, simply put, our genetic code; the female sex has XX chromosomes and the male sex has XY chromosomes. These chromosomes play a huge role in “telling” the body how to develop, especially in terms of the reproductive organs.
It appears that, in the early follicular phase of our menstrual cycle, aerobic performance outcomes are likely to be enhanced but strength performance is diminished. Similarly, endurance is diminished in the ovulatory phase, while strength and anaerobic performance improves in the same phase.
There are also variations in the findings, and some studies might suggest that there is no difference in strength throughout the menstrual cycle, so it is important to always listen to your body. What I have found to be true myself and with my menstruating clients is that the strength will vary depending on where in the cycle you are.
In one study, “The Impact of Menstrual Cycle Phase on Athletes’ Performance”, endurance performance was shown to be at its best early in the cycle, and anaerobic and strength performance may be best in the ovulatory phase; strength and aerobic performance may be worst in the late luteal phase and anaerobic performance could be worst in the late follicular phase.
Although a number of studies have found exercise performance – and in particular, endurance performance – to vary between menstrual phases, there is an equal number of such studies reporting no differences. However, a comparison of the increase in the oestrogen concentration (E) relative to progesterone concentration (P) as the E/P ratio (pmol/nmol) in the luteal phase in these studies reveals that endurance performance may only be improved in the mid-luteal phase compared with the early follicular phase when the E/P ratio is high in the mid-luteal phase.
Furthermore, the late follicular phase is characterised by the preovulatory surge in oestrogen and suppressed progesterone concentrations, which tends to promote improved performance in a cycling time trial. We hope that future studies should include this menstrual phase to explore this finding further.
Menstrual phase variations in endurance performance may largely be a consequence of changes to exercise metabolism, stimulated by the fluctuations in ovarian hormone concentrations. The literature suggests that oestrogen may promote endurance performance by altering carbohydrate, fat and protein metabolism, with progesterone often appearing to act antagonistically.
To ensure you perform and feel your best, our expert Josefine Holmberg, has put together a hormone-based training plan to align your routine and nutrition with the changes in your hormones throughout your cycle.
- Lyle McDonald. The Women's Book
- Tanja Oosthuyse, Andrew N Bosch. The effect of the menstrual cycle on exercise metabolism: implications for exercise performance in eumenorrhoeic women.
- Elliott K.J., Cable N.T., Reilly T., Diver M.J. Effect of menstrual cycle phase on the concentration of bioavailable 17-β oestradiol and testosterone and muscle strength.
- Carmichael, Mikaeli Anne et al. “The Impact of Menstrual Cycle Phase on Athletes' Performance: A Narrative Review.” International journal of environmental research and public health vol. 18,4 1667. 9 Feb. 2021, doi:10.3390/ijerph18041667
- Sung, Eunsook et al. “Effects of follicular versus luteal phase-based strength training in young women.” SpringerPlus vol. 3 668. 11 Nov. 2014, doi:10.1186/2193-1801-3-668