High-Intensity Interval Training and Menstrual Health Experience in Primary Dysmenorrhea.

This research follows a convergent mixed-methods design integrating a randomized controlled trial with a descriptive qualitative study. Fifty women (aged 18-40) with primary dysmenorrhea will be randomized into two arms: Experimental Group: 12 weeks of online supervised HIIT (2 sessions/week) plus a menstrual health educational workshop. Control Group: Menstrual health educational workshop only. Clinical variables (pain intensity via NRS, quality of life via SF-12, and pain characteristics via McGill Questionnaire) will be collected at baseline, 3 months (post-intervention), and 6 months (follow-up). Simultaneously, all participants will complete a weekly semi-structured digital diary for 12 weeks. These diaries are designed to capture the "thick description" of their menstrual health experience, focusing on the evolution of their relationship with their body and menstruation, perceptions of self-management and empowerment and barriers and facilitators for adherence to the exercise program (in the experimental group). Following the convergent design, quantitative statistical results will be integrated with the thematic analysis of the diaries. This merging of data will provide a holistic understanding of how high-intensity exercise influences not only physical symptoms but also the biopsychosocial perception of menstrual health in young women.