Association Between Exercise Habits, Including an Exercise Partner, and Menstrual Status in a Japanese Population

Introduction: Primary dysmenorrhea is a common condition in young women and substantially impairs quality of life. While exercise has preventive effects on many diseases, its association with dysmenorrhea in Asian populations remains inconsistent. We therefore investigated the relationship between exercise habits, including the presence of an exercise partner, and menstrual status, such as pain, medication use, and cycle regularity, in a young Japanese population. Methods: A total of 4892 female university students were included in this analysis. Information regarding menstrual status (regularity, pain severity, and use of medication) and exercise habits (exercise frequency, exercise intensity, and exercise partners) was obtained using a self-administered questionnaire. In the analysis, students who reported no regular exercise were used as the reference group. Results: Low (1–2 times/month) and moderate exercise frequency (1–3 times/week), light, moderate, intense exercise, and exercising with groups or friends was independently and inversely associated with menstrual pain (adjusted odds ratio [OR]: low exercise: 0.86 [95% confidence interval (CI): 0.75–0.99], moderate exercise: 0.73 [95% CI: 0.62–0.85], light: 0.82 [95% CI: 0.71–0.96], moderate: 0.85 [95% CI: 0.73–0.98], intense: 0.81 [95% CI: 0.68–0.97], groups: 0.81 [95% CI: 0.68–0.97], and friends: OR: 0.68 [95% CI: 0.56–0.82]). Similarly, exercising with friends was independently and inversely associated with the use of medication for pain (adjusted OR: 0.79 [95% CI: 0.66–0.96]). Exercise habits including exercise partner was not associated with menstrual cycle. Conclusions: Among young Japanese women, exercise habits exercising with partners were independently and inversely associated with menstrual pain.