The menstrual cycle is the monthly hormonal cycle a female’s body goes through to prepare for pregnancy. Your menstrual cycle is counted from the first day of your period up to the first day of your next period. Your hormone levels (estrogen and progesterone) usually change throughout the menstrual cycle and can cause menstrual symptoms.
A women’s menstrual cycle can impact performance. By structuring your training around your cycle, it can IMPROVE your performance. All women should be aware of this and be keen to learn more.
Further reading here