Reaction Time Across the Menstrual Cycle: A Critically Appraised Topic

Clinical Scenario : Reaction time is integral in many tasks during work, sport, and life, thus, alterations in reaction time may impact performance and injury risk. There are various factors that can influence reaction time, such as the physical state of the individual, including their age or sex. When comparing males and females, there is a major physiological difference to their physical state as hormones fluctuate during menstrual cycle phases, which not only affects the reproductive system, but females may experience physiological, cardiovascular, respiratory, or metabolic changes throughout their menstrual cycle phases. Therefore, this goal of this critically appraised topic is to examine whether reaction time changes during menstrual cycle phases. Focused Clinical Question : In healthy, eumenorrheic females, does reaction time change from one menstrual cycle phase to other menstrual cycle phases? Summary of Key Findings : Among the five studies evaluated in this CAT, all found significant changes to reaction time during phases of the menstrual cycle. Most studies found that reaction time was inversely related to sex hormone levels, indicating that phases with low hormone levels had longer reaction time than those phases with higher hormone levels; however, one study found reaction time to be prolonged or slower during the luteal phase, when hormone levels are higher. Clinical Bottom Line : Both auditory and visual reaction times vary across the menstrual cycle in healthy females with regular menstrual cycles (frequency and length). Given these findings, it is important to incorporate reaction time training across all phases of the menstrual cycle in female athletes. Strength of Clinical Recommendation : Based on the Strength of Recommendation Taxonomy, a Grade C is the strength of recommendation.