Many people with fibromyalgia and other chronic pain conditions can be active without experiencing increased pain, says a study by researchers at the University of Michigan (U-M) Health System and the Uniformed Services University of the Health Sciences in Bethesda, Md.

The study included 38 people with fibromyalgia, chronic fatigue syndrome or both conditions, and 27 healthy subjects in a control group. Rather than relying on the study volunteers' self-reporting of their activity levels, the researchers conducted round-the-clock monitoring of the subjects using high-tech devices that track daily movement.

"When you ask people with fibromyalgia about their level of function in terms of activity levels, they'll report a lower function than almost any other group," senior author Dr. Dan Clauw, director of the U-M Chronic Pain and Fatigue Research Group and a professor of rheumatology at U-M Medical School, said in a prepared statement.

"The surprising thing that we found was that their average level of activity was about the same as someone who didn't have fibromyalgia," Clauw said.

However, he and his colleagues did find that those with fibromyalgia, chronic fatigue syndrome, or both, spent much less time doing high-level activities than those in the control group.

According to Clauw, the results suggest that fibromyalgia patients report poor physical function and increased pain after activity because they report only intense activities that do cause them higher levels of pain. They don't report -- and may not realize -- that they manage some level of activity without suffering increased pain.

"We've probably been thinking about fibromyalgia incorrectly. This group was impaired, but they weren't impaired in the way they though they would be. This is good news for fibromyalgia patients," Clauw said.

The findings could lead to changes in the treatment of people with chronic pain in the muscles and soft tissue, he noted.

"Exercise and activity are essential to the well-being of people with fibromyalgia. Our research shows that higher activity is not, in fact, leading people to increased pain, and it could be used to show patients that they can be active," Clauw said.

The study appears in the current issue of Arthritis & Rheumatism.

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