How do hormones influence exercise performance?

Apart from the roles that hormones have on fertility and reproduction, they also affect other metabolic systems, such as the cardiovascular and respiratory systems. These effects might have an impact on women’s performance during exercise, however, these effects are not completely clear now, since the results from the scientific studies are sometimes contradictory.

First, let’s recapitulate how the menstrual cycle can be divided. One way is to divide it into three phases: The early follicular phase: from day 1 to 5 of an idealized 28 days cycle. Characterized by low oestrogen and progesterone levels. The ovulatory phase: from day 12 to approximately 15. In this phase, there are high oestrogen levels but low progesterone. The mid-luteal phase: from day 20 to around 23. In this case, both oestrogen and progesterone are in high concentration.

Now, regarding the role of the hormones during physical activity, oestrogen is characterized by having anabolic effects, which means that it has metabolic activities concerned with biosynthesis, so it is a state when the body is in a “building up” environment. Oestrogen also has an impact on important features during exercise, like vascular flow modulation, glycogen utilization, and increases fat utilization. Also, the oestrogen antioxidant and membrane stabilizer properties might give protection against exercise-induced muscle damage. On the other side, progesterone has anti-oestrogenic effects, it increases the ventilation and the body temperature at rest during the luteal phase compared with the follicular phase. A higher body temperature during the luteal phase could affect the perceptual and physiological responses during the exercise, increasing the fatigability perception. Fatigability is defined as the exercise-induced reduction in force, and it is influenced by the individuals’ subjective perceptions during a specific task or exercise. Therefore, because this is a subjective measurement, it can be difficult to study.

It has been suggested that on average the exercise performance might be reduced during the early follicular phase (low oestrogen and progesterone) compared with all the other phases. The beneficial performance effects of oestrogen might be bigger in the late follicular and ovulatory phases when oestrogen and progesterone are low, compared to the mid-luteal phase when both oestrogen and progesterone are high. However, the effects of fluctuations in oestrogen and progesterone across the menstrual cycle on exercise performance are not completely clear. There have been different results within studies. One of the explanations for the lack of agreement between studies is the estrogen-to-progesterone concentration ratio, which can be very variable between women, making it even more difficult to study the effect of hormones on exercise.

References: McNulty, K.L., Elliott-Sale, K.J., Dolan, E. et al. The Effects of Menstrual Cycle Phase on Exercise Performance in Eumenorrheic Women: A Systematic Review and Meta-Analysis. Sports Med 50, 1813–1827 (2020). https://doi.org/10.1007/s40279-020-01319-3 Pereira, H., Larson, R., Bemben, D. Menstrual Cycle Effects on Excercise-Induced Fatigability. Front. Physiol 2020 11(517). https://doi.org/10.3389/fphys.2020.00517