TIMING MATTERS FOR FEMALE RUNNERS

New research by UK scientists has found that running economy in female athletes is significantly impaired during the mid-luteal phase of the menstrual cycle (around one week before menstruation) ( https://www.ncbi.nlm.nih.gov/pubmed/32037785 ). Reduced running economy means more energy expended per mile at a given running speed, with implications for the timing of important races or particularly hard training sessions.
Learn more about how the menstrual cycle affects performance, immunity and nutrition requirements in this Peak Performance article: https://www.peakendurancesport.com/nutrition-for-endurance-athletes/fuelling-and-hydration-for-exercise/fluid-carbohydrate-immunity-women-know/