The study is the first to look at the effects of yoga on cortisol levels in women with fibromyalgia. The condition, which predominantly affects women, is characterized by chronic pain and fatigue; common symptoms include muscle stiffness, sleep disturbances, gastrointestinal discomfort, anxiety and depression.

Previous research has found that women with fibromyalgia have lower-than-average cortisol levels, which contribute to pain, fatigue and stress sensitivity. According to the study, participants' saliva revealed elevated levels of total cortisol following a program of 75 minutes of hatha yoga twice weekly over the course of eight weeks.