Women with endometriosis present with symptoms of chronic pelvic pain (1), which can influence their general exercise levels and pelvic floor muscle (PFM) function. International clinical guidelines advocate for a multimodal approach to managing endometriosis pain, with exercise training being recommended for its overall health benefits. However, the need for high-quality randomized controlled trials (RCTs) hampers the ability to ascertain the specific effectiveness of exercise training in alleviating endometriosis-related pain. Pelvic floor muscle training (PFMT) has also been hypothesized to decrease PFM tone (2), which may reduce pelvic pain and could be included in a general exercise program. Thus, the aim of this study was to investigate whether group-based pain education and supervised group-based general exercise training, including PFMT, compared to pain education alone, relieves genito-pelvic pain in women with endometriosis. The secondary aim was to investigate whether an effect of PFMT was associated with a change in vaginal resting pressure (VRP), vaginal resting activity (VRA), PFM strength/maximal voluntary contractions (MVC) and PFM endurance.

This was an assessor-blinded, two-arm, parallel-group RCT among 81 women with laparoscopic-confirmed endometriosis conducted between 2022 and 2024. The participants completed an electronic questionnaire that included background data. In addition, genito-pelvic pain was registered as pain at its best, worst, and average pain over the course of one month using the numeric rating scale (NRS) ranging from 0-10. PFM assessments included VRP, MVC and PFM endurance using a manometer/precision pressure transducer connected to a vaginal balloon and measured in cmH2O. VRA was assessed by sEMG (NeuroTrac MyoPlus Pro) with a probe inserted vaginally, with the electrodes placed in the 3 and 9 o’clock positions and the ring in a vertical position, quantified as average microvolts (μV). All participants were instructed on the correct technique for PFM contraction and relaxation after the contraction before measurements were taken. At four months, the same questionnaires and PFM assessments were performed.
 
Women with laparoscopic-confirmed endometriosis, aged 18-45, able to participate in an exercise group, and presenting with genito-pelvic pain, were eligible for inclusion. The participants were recruited at one of two university hospitals specializing in endometriosis care or through social media. Exclusion criteria were intra-abdominal/vaginal surgery and botox during the past six months; severe pathology (malignancy), cardiovascular conditions and immune system diseases; pregnancy/childbirth/breastfeeding within the last 12 months and severe psychiatric disorders. Women who had recently initiated or adjusted ongoing hormonal therapy were eligible for inclusion after a waiting period of three months. All women gave their written consent prior to participation.
 
All participants attended a pain management course with information regarding the potential benefits of general exercise training and PFMT before being randomized to an exercise group (n=41) or control group (n=40). A statistician handled the randomization sequence, and the allocation was concealed. 
 
The exercise group were encouraged to follow the recommendation for the American guidelines for physical activity for adults for weekly exercise (3). The exercise group then followed a weekly 60-minute group training for four months led by a women’s health physiotherapist. The group training consisted of a standardized program that included endurance, strength training of large muscle groups, PFMT, and flexibility training. The PFMT included 8–10 repetitions of maximal contraction held for 6–8 seconds in 3 series. An additional individually tailored progressive home exercise program, including daily PFMT, was also performed. 

The intensity, number, and length of home training sessions and any adverse effects were recorded through a training diary. 
  
The control group received no further follow-up. 
 
Sample size estimation was based on results from a similar exercise program in a group of women with endometriosis resulting in a reduction of genito-pelvic pain of 1 point on an NRS-scale (SD 1.19). With 90% power, 5% significance level and calculated drop-out of 20%, the final estimation was 38 participants in each group. To allow for some additional loss to follow-up, another 5 women were included. 
 
Background variables are presented as means with standard deviations (SD) or numbers with percentages (%). The mean difference in outcome measures between the groups was measured using t-tests. ANCOVA assessed changes from baseline to week 16 and reported as mean and 95%CI. Analyses were based on intention to treat (ITT) and per protocol, including participants attending >50% of the sessions in the exercise group or following the home training program >50% of the time and PFMT twice a week or a minimum of 2 workouts per week on average. P-values <0.05 were considered statistically significant.

Of the 81 women included, 5 (12%) from the exercise group and 2 (5%) from the control group were lost to follow-up. 
 
Mean age was 29.4 years (range 18–43), mean BMI was 25.2 (SD± 4.99) and average time since diagnosis was 5 years (range 2–21). Thirty-three (40.2%) had >4 years of higher education and 9/81 (11%) were parous. 
   
The ITT analysis revealed a significant reduction in average genito-pelvic pain in the exercise group compared to the control group, with a mean difference of 1.2 (95%CI 0.1,2.2) (Table 1). The per-protocol analysis was based on 20 women (49%) following the prescribed group exercises and home training. A mean difference in genito-pelvic pain at its worst (1.6, (95%CI 0.2, 3)) and a mean difference in average pain (1.7, (95%CI 0.4, 2.9)) favouring the exercise group was found. Neither the ITT nor the per-protocol analysis revealed any significant between-group differences in VRP, MVC, PFM muscular endurance or VRA (table 2). No adverse effects were reported.

Among women with endometriosis, supervised general exercise training, including PFMT, improved genito-pelvic pain, compared to women participating in a pain management course only. A per-protocol analysis revealed that the effect of exercise training was even larger among women following the prescribed exercise regimen. These results highlight the importance of supervision in achieving a preferred dosage of exercise. However, no change in PFM variables was found. The exercise group may not have directly influenced PFM muscle strength in this study. However, the tendency towards lesser VRA and VRP, albeit not statistically significant, may still be relevant to the reduction in pain observed in the exercise group. A study found that a PFM contraction led to a statistically significant reduction of VRP (2); extending the duration of the training period (>6 months) or increasing the frequency of PFMT sessions might result in additional improvements in PFM function.

The results from this RCT indicate that supervised general exercise training, including PFMT, improves genito-pelvic pain among women with endometriosis. Thus, clinicians should carefully empower their patients with knowledge and skills in implementing exercise training as part of their treatment.

Becker CM, Bokor A, Heikinheimo O, Horne A, Jansen F, Kiesel L, et al. ESHRE guideline: endometriosis. Hum Reprod Open. 2022;2022(2):hoac009
Naess I, Bo K. Can maximal voluntary pelvic floor muscle contraction reduce vaginal resting pressure and resting EMG activity? Int Urogynecol J. 2018;29(11):1623-7
Piercy KL, Troiano RP, Ballard RM, Carlson SA, Fulton JE, Galuska DA, et al. The Physical Activity Guidelines for Americans. Chicago2018. p. 2020-8