Strength Exercise Has Different Effects on Pressure Pain Thresholds in Women with Endometriosis-Related Symptoms and Healthy Controls: A Quasi-experimental Study

Objective. To evaluate the influence of strength exercises on remote pain sensitivity in women with endometriosis-related symptoms. Design. A quasi-experimental study. Setting. University Hospital, a tertiary health unit. Subjects. Twenty-one women with endometriosis-related symptoms and 21 healthy women provided written informed consent. Methods. The participants performed weekly exercise sessions on an extensor chair for four consecutive weeks. An electronic algometer was used to measure the pressure pain thresholds on the nondominant forearm. Heart rate and blood pressure were measured using a digital device. All measurements were taken before, immediately after, and 10 and 20 minutes after the exercise series. Results. Women with endometriosis-related symptoms had lower pain thresholds. Pressure pain thresholds increased immediately after exercise in healthy women, returning to baseline level 20 minutes after exercise. Women with endometriosis-related symptoms did not present significant pressure pain threshold alterations after exercise. However, they had a higher heart rate and systolic, diastolic, and average blood pressure than healthy women at all the timepoints. There were no consistent correlations between pressure pain thresholds and heart rate or blood pressure. Conclusions. The strength exercise regimen used in this study increased pain thresholds in healthy women but not in women with endometriosis-related painful symptoms. The maintenance or even worsening of pain perception after exercise in women with persistent pain, such as those with endometriosis, may limit their adherence to a physical training program, which in turn could prevent them from experiencing the long-term beneficial effects of exercise.