Scientists are currently studying the female cycle and revolutionizing medicine, sports and women’s private lives with groundbreaking results. A study by Stanford University in 2021 demonstrates the immense importance of the female cycle. In comparison, the circadian rhythm has a much smaller impact on humans. Researchers evaluated 241 million observations from 3.3 million women in 109 countries on 15 aspects of vital signs, state of mind and be- havior. In the study, they noted not only the enormous influence of the menstrual cycle, but also how little it has been researched at all to date.