Exercise leaves women's cycle hormones largely where they were

Estrogen, progesterone and testosterone rise and fall across the menstrual cycle, and those fluctuations affect strength and postural stability, with knock-on implications for injury and fall risk in women. If exercise itself could modulate these hormones, that would matter twice over: for athletes thinking about training across their cycle, and for the broader health of anyone who menstruates and trains. Yet the evidence on whether exercise actually shifts sex steroid hormones in women with regular cycles has been scattered across small studies of varying quality. This review set out to pull that evidence together into one answer.

The authors followed standard systematic review methods and searched PubMed, Web of Science and Google Scholar for studies in eumenorrheic women, meaning women with regular menstrual cycles. They accepted both randomised controlled trials and single-group experimental studies, comparing any type of exercise against no exercise in a control group. Eleven studies qualified: 5 randomised controlled trials and 6 quasi-experimental designs. The primary outcomes were levels of estrogen, progesterone and testosterone, with study quality screened using the Cochrane risk of bias tool.

Exercise produced no statistically significant effect on free estradiol concentration, and no significant effect on serum progesterone either, with the progesterone studies disagreeing with one another substantially. Testosterone was the exception: the pooled analysis reported a statistically significant effect of exercise on testosterone levels, though here too the underlying studies varied widely in their results. In short, the two hormones that dominate the menstrual cycle appeared unmoved, while the androgen signal was significant but rested on inconsistent data. The authors close by calling for a blinded randomised trial using a structured approach with warm-ups, cool-downs and rest intervals.

Women remain underrepresented in exercise science, and reviews like this one show how thin the foundational evidence still is: eleven studies, nearly half of them without randomisation, addressing a question that affects half the training population. The null results for estradiol and progesterone are reassuring as far as they go, but with this much disagreement between studies they are a holding position rather than a settled answer. The testosterone finding is intriguing but needs replication in better-designed trials before anyone builds on it. The blinded randomised trial the authors propose is the obvious next step.

If you menstruate and train regularly, the current evidence gives no clear sign that exercise is disrupting your estrogen or progesterone, which is the worry that most often surfaces around hard training and hormonal health. It also offers a hint, no more, that exercise may influence testosterone in women, though the studies behind that signal disagree too much for it to carry weight yet. The sensible reading is that this question remains open, and that strong claims in either direction, whether that training wrecks your hormones or optimises them, are running ahead of the data.