The effect of isometric exercise on the intensity and duration of pain among physically inactive young females with primary dysmenorrhea

Introduction: Primary dysmenorrhea (PD) is defined as recurrent, cramp-like pain occurring with normal ovulatory menses in the absence of any pelvic pathology. Isometric exercise is a subgroup of exercises, during which the muscle length and joint remain constant during contraction. To date, the effectiveness of isometric exercise in reducing the intensity and duration of PD is not yet established. Objective: The aim of the study is to investigate the effect of isometric exercise on the intensity and duration of PD among physically inactive young females. Methods: In this randomised controlled trial, twenty-four young females with PD were randomly assigned to either exercise or control groups, with twelve participants in each group. While participants in the control group continued with their physically inactive lifestyle, participants in the exercise group were required to perform isometric exercises for eight weeks, five days per week, two sessions per day, and ten minutes per session. Pain intensity and duration of all the participants were measured during menses at pre, mid and post-test. The intensity of pain was measured by using the Visual Analogue Pain Scale (VAPS) and the duration of pain was recorded in hours. The data was analysed by Mixed ANOVA, SPSS version 26.0. Results: After eight weeks of isometric exercise intervention, the mean score of pain intensity was significantly reduced in the exercise group (6.08 to 1.92) (p = 0.002), while it remained constant in the control group (6.25 to 6.58) (p = 0.126). The mean duration of pain (hours) was also significantly reduced in the exercise group (10.00 to 2.00 hours) (p = 0.000) but remained constant in the control group (9.25 to 9.42 hours) (p = 0.691). Conclusion: The mean intensity and duration of menstrual pain were significantly reduced after eight weeks of isometric exercise intervention. It appears that isometric exercise is an effective non-pharmacological method to induce a positive reduction in intensity and duration of pain for primary dysmenorrhea.