Background: Exercise has a number of health benefits and has been recommended as a treatment for primary dysmenorrhoea (period pain), but the evidence for its effectiveness on primary dysmenorrhoea is unclear. This review examined the available evidence supporting the use of exercise to treat primary dysmenorrhoea.
Objectives: To evaluate the effectiveness and safety of exercise for women with primary dysmenorrhoea.
Search methods: We searched the Cochrane Gynaecology and Fertility specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, AMED and CINAHL (from inception to July 2019). We searched two clinical trial databases (inception to March 2019) and handsearched reference lists and previous systematic reviews.
Selection criteria: We included studies if they randomised women with moderate-to-severe primary dysmenorrhoea to receive exercise versus no treatment, attention control, non-steroidal anti-inflammatory drugs (NSAIDs) or the oral contraceptive pill. Cross-over studies and cluster-randomised trials were not eligible for inclusion.
Data collection and analysis: Two review authors independently selected the studies, assessed eligible studies for risk of bias, and extracted data from each study. We contacted study authors for missing information. We assessed the quality of the evidence using GRADE. Our primary outcomes were menstrual pain intensity and adverse events. Secondary outcomes included overall menstrual symptoms, usage of rescue analgesic medication, restriction of daily life activities, absence from work or school and quality of life.
Main results: We included a total of 12 trials with 854 women in the review, with 10 trials and 754 women in the meta-analysis. Nine of the 10 studies compared exercise with no treatment, and one study compared exercise with NSAIDs. No studies compared exercise with attention control or with the oral contraceptive pill. Studies used low-intensity exercise (stretching, core strengthening or yoga) or high-intensity exercise (Zumba or aerobic training); none of the included studies used resistance training.Exercise versus no treatmentExercise may have a large effect on reducing menstrual pain intensity compared to no exercise (standard mean difference (SMD) -1.86, 95% confidence interval (CI) -2.06 to -1.66; 9 randomised controlled trials (RCTs), n = 632; I2= 91%; low-quality evidence). This SMD corresponds to a 25 mm reduction on a 100 mm visual analogue scale (VAS) and is likely to be clinically significant. We are uncertain if there is any difference in adverse event rates between exercise and no treatment.We are uncertain if exercise reduces overall menstrual symptoms (as measured by the Moos Menstrual Distress Questionnaire (MMDQ)), such as back pain or fatigue compared to no treatment (mean difference (MD) -33.16, 95% CI -40.45 to -25.87; 1 RCT, n = 120; very low-quality evidence), or improves mental quality of life (MD 4.40, 95% CI 1.59 to 7.21; 1 RCT, n = 55; very low-quality evidence) or physical quality of life (as measured by the 12-Item Short Form Health Survey (SF-12)) compared to no exercise (MD 3.40, 95% CI -1.68 to 8.48; 1 RCT, n = 55; very low-quality evidence) when compared to no treatment. No studies reported on any changes in restriction of daily life activities or on absence from work or school.Exercise versus NSAIDsWe are uncertain if exercise, when compared with mefenamic acid, reduced menstrual pain intensity (MD -7.40, 95% CI -8.36 to -6.44; 1 RCT, n = 122; very low-quality evidence), use of rescue analgesic medication (risk ratio (RR) 1.77, 95% CI 1.21 to 2.60; 1 RCT, n = 122; very low-quality evidence) or absence from work or school (RR 1.00, 95% CI 0.49 to 2.03; 1 RCT, n = 122; very low-quality evidence). None of the included studies reported on adverse events, overall menstrual symptoms, restriction of daily life activities or quality of life.
Authors' conclusions: The current low-quality evidence suggests that exercise, performed for about 45 to 60 minutes each time, three times per week or more, regardless of intensity, may provide a clinically significant reduction in menstrual pain intensity of around 25 mm on a 100 mm VAS. All studies used exercise regularly throughout the month, with some studies asking women not to exercise during menstruation. Given the overall health benefits of exercise, and the relatively low risk of side effects reported in the general population, women may consider using exercise, either alone or in conjunction with other modalities, such as NSAIDs, to manage menstrual pain. It is unclear if the benefits of exercise persist after regular exercise has stopped or if they are similar in women over the age of 25. Further research is required, using validated outcome measures, adequate blinding and suitable comparator groups reflecting current best practice or accounting for the extra attention given during exercise.