1 Department of Physics, Concordia University, Canada.
2 School of Health, Concordia University, Canada.
3 Centre ÉPIC, Montreal Heart Institute, Montréal, Québec, Canada.
4 BrainLab, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Ontario, Canada.
5 Sandra Black Centre for Brain Resilience and Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada.
6 Department of Medicine, Université de Montréal, Montréal, Québec, Canada.
7 Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
8 Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.
9 Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, Canada.
10 Department of Medical Biophysics, University of Toronto, Toronto, Canada.
11 Department of Biomedical Engineering, University of Toronto, Toronto, Canada.

Cerebrovascular reactivity (CVR) and cerebral pulsatility (CP) are important indicators of cerebrovascular health and have been shown to be associated with physical activity (PA). Sex differences have been shown to influence the impact of PA on cerebrovascular health. However, the sex-specific effects of PA on CP and CVR, particularly in relation to intensity and dosage of PA, remains unknown. Thus, this cross-sectional study aimed to evaluate the sex-specific effects of different intensities and doses of PA on CVR and CP. The Human Connectome - Aging dataset was used, including 626 participants (350 females, 276 males) aged 36-85 (mean age: 58.8 ± 14.1 years). Females were stratified into premenopausal and postmenopausal groups to assess the potential influence of menopausal status. Novel tools based solely on resting state fMRI data were used to estimate both CVR and CP. The International Physical Activity Questionnaire was used to quantify weekly self-reported PA as metabolic equivalent of task. Results indicated that both sexes and menopausal subgroups revealed negative linear relationships between relative CVR and PA. Furthermore, females presented a unique non-linear relationship between relative CVR and total PA in the cerebral cortex. In females, there were also relationships with total and walking PA in occipital and cingulate regions. In males, we observed relationships between total or vigorous PA and CVR in parietal and cingulate regions. Sex-specific effects were also observed with CP, whereby females benefited across a greater number of regions and intensities than males, especially in the postmenopause group. Overall, males and females appear to benefit from different amounts and intensities of PA, with menopause status significantly influencing the effect of PA on cerebrovascular outcomes, underscoring the need for sex-specific recommendations in promoting cerebrovascular health.