Summary: A UCL study found that women’s cognitive performance—measured by reaction time and accuracy—peaked at ovulation, but physical activity level had a far greater overall impact. Inactive participants were, on average, about 70 milliseconds slower and made roughly three times more impulsive errors than active women, independent of menstrual phase.
The research indicates that regular exercise has a stronger, more consistent effect on brain function than the natural hormonal fluctuations of the menstrual cycle. These results have practical implications for athletic performance, injury prevention and everyday coordination, and challenge common assumptions that menstruation necessarily impairs cognitive ability.
Key Facts:
- Best performance at ovulation: Participants reacted about 30 milliseconds faster and made fewer mistakes on the day ovulation was detected compared with later in the cycle.
- Activity outweighs cycle effects: Across all phases, physically active women outperformed inactive participants by roughly 70 milliseconds and showed far fewer impulsive errors.
- Real-world relevance: Small gains in reaction time can reduce injury risk in sport and improve everyday responses such as regaining balance after a trip.
Source: UCL
Women performed best on cognitive tests during ovulation, but physical activity had the strongest influence on brain function, according to a new UCL study.
Published in Sports Medicine – Open, the study examined how menstrual cycle phases and levels of physical activity affected performance across a set of cognitive tasks designed to reflect processes used in team sports and daily life—attention, inhibition, precise timing of movements and reaction speed.
Researchers measured cognitive performance at four key times in the cycle: the first day of menstruation (early follicular), two days after bleeding stopped (late follicular), the day ovulation was detected, and the mid-luteal phase between ovulation and the next period. Reaction time and accuracy were recorded alongside mood and symptom reports.
Overall, reaction times were fastest and errors fewest on the day ovulation was detected. However, differences between active and inactive participants were substantially larger than differences between cycle phases. Inactive participants averaged about 70 milliseconds slower reactions and made approximately three times as many impulsive errors compared with active women, irrespective of where they were in their cycle.
The investigators note that a modest advantage of around 20 milliseconds—seen between some cycle phases—could be meaningful at elite sporting levels, where split-second differences influence the likelihood of incidents such as collisions or concussions. Still, the larger gap tied to activity level is more consequential for everyday safety and function; for example, it can determine whether someone recovers balance after stumbling.
Dr Flaminia Ronca, the study’s lead author from UCL Surgery and Interventional Science and the Institute of Sport, Exercise & Health, said this is the first study in this context to directly confirm ovulation and show improved cognitive performance at that phase. She highlighted that while ovulation produced a measurable boost (about 30 milliseconds), the advantage associated with being physically active (about 70 milliseconds) is greater and more actionable for daily life.
“Incorporating recreational physical activity into daily life can improve reaction time and cognitive performance,” Dr Ronca said. “This does not have to be intense or competitive—short bouts of moderate activity are sufficient and are something individuals can control.”
The study included 54 naturally menstruating women aged 18–40, grouped by athletic participation: inactive (no structured exercise), recreationally active (at least two hours of structured exercise per week), club-level competitors and elite athletes (national/international competition). Participants completed mood questionnaires and a battery of cognitive tests at each phase.
Consistent with earlier findings, reaction times slowed during the mid-luteal phase, a period when progesterone levels are higher; this likely contributes to reduced processing speed. However, slower reaction times during that phase did not translate into higher error rates, suggesting accuracy can be maintained despite slower processing. More errors were observed in the late follicular phase, an outcome the authors note requires further investigation.
Notably, participants reported worse mood and more symptoms during menstruation, and 55% believed their performance was impaired at that time. Objective test results did not support this perception—reaction times during menstruation were not worse than during the mid-luteal phase and, in some measures, were faster.
Evelyn Watson, a co-author, emphasized that the data do not support the common assumption that menstruation necessarily degrades cognitive function. “If anything, performance peaked at ovulation,” she said, adding that these findings can help reshape narratives around female health and performance in sport.
Dr Ronca closed by noting that even brief periods of moderate exercise—such as a 15-minute brisk walk or cycling to the shops—have been shown in previous studies to boost mood and cognitive function, making regular activity an achievable strategy to improve everyday and athletic cognitive performance.
Key Questions Answered:
A: Women showed faster reaction times and made fewer errors on the day ovulation was detected, indicating a peak in cognitive performance at that phase.
A: Physical activity had a larger effect than menstrual phase—active participants reacted substantially faster and more accurately across all phases.
A: Regular exercise offers a major cognitive benefit that outweighs the modest fluctuations across the menstrual cycle, potentially lowering injury risk in sport and improving daily coordination.
About this cognition, exercise, and ovulation research news
Author: Matt Midgley
Source: UCL
Contact: Matt Midgley – UCL
Image: The image is credited to Neuroscience News
Original Research: Open access. “Menstrual cycle and athletic status interact to influence symptoms, mood, and cognition in females” by Flaminia Ronca et al., Sports Medicine – Open
Abstract
Menstrual cycle and athletic status interact to influence symptoms, mood, and cognition in females
Background
Interest is growing in how the menstrual cycle affects physical and cognitive performance, especially in athletic contexts. Although hormonal changes are commonly thought to influence cognition—particularly during menstruation—the evidence has been inconsistent. This study investigated whether cognition, mood and symptoms vary across menstrual phases and whether athletic participation level moderates these effects.
Results
Fifty-four women aged 18–40 were classified by athletic participation (inactive, active, competing, elite). At menstruation, late follicular, ovulation and mid-luteal phases they completed a cognitive battery assessing attention, inhibition and spatial anticipation and reported mood and symptoms. Reaction times were faster and errors fewer during ovulation (p < .01). Reaction times slowed in the mid-luteal phase (p < .01), while error rates increased in the late follicular phase (p = .01). Athletic level had a larger influence on cognitive performance than cycle phase: inactive participants consistently scored worse, while elite athletes showed larger phase-related fluctuations. Mood and symptoms were worse during menstruation, but these subjective reports did not correlate with objective cognitive performance.
Conclusion
The study demonstrates mild cognitive fluctuations across the menstrual cycle with substantial individual variability and a mismatch between perceived and measured performance. These findings challenge assumptions about menstruation-related cognitive decline and underscore the greater, positive impact of regular physical activity on cognitive function.