What Your Cycle Really Does to Your Brain
Your menstrual cycle changes how your brain works, but not how you thought it might.
Posted November 11, 2025 | Reviewed by Michelle Quirk
It’s game day. Your kit is washed and folded, your bag is packed, and your shoes are ready for you to boot up. And yet, you’re sitting on the edge of your bed, clutching your waist, wishing women weren’t made this way. You’re in pain, you’re tired, you’re in a bad mood, and you’re simply just not feeling it. Not today.
So many athletes live through the experience of "getting on with it" in the face of pain, uncertainty, and the fear of not being able to perform at their best when experiencing menstrual symptoms. There are many academic papers covering these preconceptions, collectively indicating that a majority of athletes perceive that they perform worse when on their period. But do they?
This unhelpful narrative still pervades schools, workplaces, and football pitches. However, the latest research challenges some preconceived biases, bringing a positive light to the table. Do hormonal changes impact mood and cause symptoms? Yes. Do they impact cognitive performance? Yes. But the story is far more exciting than society has assumed so far. So, let’s start breaking down a few misconceptions.
Piecing the puzzle together
A few years ago, over coffee with a colleague, we were discussing the curious phenomenon of female athletes exhibiting a higher incidence of injury in specific phases of their cycles, namely the mid-luteal phase (about a week before menstruation). Many sport medicine articles hypothesise that changes in tendon laxity and muscular function are the likely cause of these patterns in injury risk. The problem with these theories is that there isn’t any robust empirical evidence that tendon laxity or muscular function changes by phase, and perhaps, this explanation might just be too simplistic. The brain plays a determining role in decision-making and timing of movements, especially in fast-paced environments like team sports, where these injuries are being observed. There are many studies that demonstrate that slower reaction times can predict greater injury risk (in male athletes, of course). However, we couldn’t find any articles that investigated possible sport-related cognitive changes in females throughout the menstrual cycle. So we decided to launch an investigation. After all, all good science happens over drinks.
Our first proof-of-principle paper took a light-touch approach, sending a long cognitive battery to more than 300 participants online, just to test if we could find any pattern at all. The findings hinted at slower reaction times during the luteal phase, as we hypothesised (where other research reports higher injury rates in team sports). However, the most exciting finding lay elsewhere: Participants felt worse during menstruation, and they assumed that their symptoms were negatively impacting their cognitive performance… but they were actually performing better than in other phases, with faster reaction times and fewer errors. This provided the basis for positive conversations in both sport and across the media , which challenged the societal misconception of supposed worse performance during periods.
Capturing more robust evidence
The findings were exciting, but still preliminary. We needed to confirm them with more robust methods. The following year saw two incredible researchers, Evelyn Watson and Isabel Metcalf, tracking 54 women and their menstrual cycles, asking them to complete cognitive tests during specific phases. While Evie pestered volunteers about their period dates, Izzy bicycled around London delivering ovulation kits to capture their hormonal changes. We hoped to complete the study in two months, which sorely turned into 12. If a time point was missed, we had to wait at least 28 days until we could book a next testing session. Women are complicated to study; no wonder most research still recruits males ! But it is precisely this intricate puzzle that makes us so beautifully fascinating.
This meticulous approach enabled us to identify the day of ovulation and obtain more accurate cycle tracking than in the previous study, revealing even more interesting results . Reaction times were still slower in the mid-luteal phase (without a difference in errors)—a replicable result that may point toward a possible link between slower reactions and increased risk of injury in contact sports. The mid-luteal phase (about a week before menstruation) is characterised by a peak in progesterone and greater inflammation, both of which are known to produce an inhibitory effect on the cerebral cortex and, therefore, slower reaction times.
Mood doesn’t determine performance
Another replicable result was the incongruence between perception and performance: Participants felt considerably worse during menstruation, and the majority assumed that their symptoms were negatively impacting their cognitive performance. However, there was no detriment to reaction times nor errors on this day. The point is this: The way we feel does not determine the way we perform . This reinforces the importance of breaking societal biases that assume that going through "that time of the month" makes us somehow more vulnerable. It doesn’t.
Peaking performance during ovulation
The new and exciting discovery was the identification of peak performance on the day of ovulation. Participants had faster reaction times, made fewer errors, and felt more alert and energetic on the day of ovulation. (This wasn’t identified in the previous study, because ovulation can only be captured with hormonal testing). Theoretically, this could be linked to the peak in oestrogen experienced just before ovulation, which is known to have excitatory effects on the cerebral cortex.
The one surprising finding was that elite athletes exhibited greater fluctuations in reaction times throughout the cycle compared to the rest of the study sample. While this strengthens the theory that cognitive changes in athletes could underpin patterns in injury risk, it’s not very clear why this effect was so strong in this group. Elite sport puts the body under incredible strain, which can lead to hormonal dysregulation in some women. It’s possible that stronger fluctuations in hormonal changes in elite athletes might explain the greater changes in reaction times observed in this study, but we did not measure hormone levels and must therefore leave this to speculation—for now.
Lifestyle matters more than phase
Perhaps most importantly, women in this study who were recreationally active performed best on the cognitive tests and had the most stable profile across their menstrual cycle, while women who were inactive performed consistently worse across all tasks, and in all phases. Physical activity played a significant role in how our participants performed on the cognitive tests, but that’s a story for another post.
We perform, every day
In brief, feeling worse during our period does not determine our cognitive or physical performance. Let’s not forget the sheer number of Olympic medals that were won by athletes while on their periods, and all the "normal" women making spectacular achievements every day of their lives, who were far from interested in their hormonal levels when they nailed an interview, scored a goal, or passed an exam.
The truth is that women perform every single day in spite of pain, fatigue, or uncertainty. We don’t just cope; we conquer. Period.
Ronca, F., Watson, E., Metcalf, I. and Tari, B., 2025. Menstrual Cycle and Athletic Status Interact to Influence Symptoms, Mood, and Cognition in Females. Sports Medicine-Open , 11 (1), p.104.
Ronca, F., Blodgett, J.M., Bruinvels, G., Lowery, M., Raviraj, M., Sandhar, G., Symeonides, N., Jones, C., Loosemore, M., and Burgess, P.W., 2025. Attentional, anticipatory and spatial cognition fluctuate throughout the menstrual cycle: Potential implications for female sport. Neuropsychologia , 206 , p.108909.
Cowley, E.S., Olenick, A.A., McNulty, K.L., Ross, E.Z., 2021. “Invisible sportswomen”: the sex data gap in sport and exercise science research. Women Sport Phys Activ J. 29 (2), 146–151.
Martin, D., Timmins, K., Cowie, C., Alty, J., Mehta, R., Tang, A., Varley, I., 2021. Injury incidence across the menstrual cycle in international footballers. Frontiers in Sports and Active Living , p. 17.
Gatens K. I’m sharper and more focused: why women can play better on their period. The Times. June 9, 2024.
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Flaminia Ronca, Ph.D. , is an academic at University College London, where she conducts scientific research on the interaction between the body and the brain in the context of physical activity and health.
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This article is part of the Bringwise Psychology Journal — daily insights on human behavior, mental health, and personal growth.