BBC Sport - Dealing with periods 'fundamental' when competing as an athlete
Do periods affect performance?
- From the section Wales
It was described by former British No 1 tennis player Annabel Croft as "the last taboo" in sport - the impact of women's menstrual cycle on their athletic performances.
It made headlines when British tennis player Heather Watson said she was feeling unwell during her loss in the first round of the Australian Open, blaming "girl things".
As part of the Health Check Wales season, Sport Wales sought the views of sports stars Baroness Tanni Grey Thompson and Non Evans on how they dealt with their periods during their careers.
Watch Sport Wales on Friday nights at 7pm on BBC Two Wales; and on iPlayer for seven days after transmission.