Sex differences in exercise efficacy: Is midlife a critical window for promoting healthy cognitive aging?

Dementia is one of the most pressing health care issues of this century. As no curative treatment for dementia exists, research efforts are growing to identify effective lifestyle interventions to prevent or delay onset. One such promising strategy that promotes cognitive and brain health is engaging in physical exercise. However, current exercise recommendations are imprecise. To advance the potential of exercise as a preventative and treatment strategy, important questions regarding moderators (ie, biological sex and age) are being addressed in the literature. Biological sex is recognized as an important variable to consider in exercise efficacy on brain health, with females showing greater cognitive gains. This may be related to sex differences in underlying mechanisms. Here, we argue to better understand the sex differences in exercise efficacy, the timing of exercise intervention should also be considered. Specifically, we present the hypothesis that midlife in females is a critical window for the implementation of exercise as an early intervention to promote brain health and prevent dementia. Further, we speculate that exercise interventions targeting midlife will be of critical importance for the female brain, as females exit this period of the lifespan at greater risk for cognitive impairment. Given the potential sex differences in dementia risk and prevalence, it is imperative to assess potential sex differences in exercise efficacy as an early intervention during midlife.