Exercise Combats Cancer-related Fatigue, Review Shows

The meta-analysis of 28 studies of cancer-related fatigue found that exercise is more effective at combating the problem than the usual care provided to patients.

"A lot of the time, the medical response to patients is that they should expect to be fatigued, that it is a normal side effect. If patients are told that fatigue is just a side effect and to accept it, what they are not getting is any advice or support to help them cope," said lead review author Fiona Cramp.

The review appears in a recent issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

People saddled with cancer-related fatigue describe it in many ways, including a weighed-down feeling and constant lack of energy that can result in diminished interest in work and family life.

The studies tested exercise programs that lasted anywhere from three weeks to eight months, but the typical intervention lasted twelve weeks. Many of the studies measured the effect of walking or stationary bike riding, but the length, type and intensity of exercise varied widely across the studies.

The researchers pooled data from more than 2,000 people with cancer.

"Exercise shouldn't be used in isolation but should definitely be included as one of the components in the package of interventions used during and after treatment," said Cramp, a lecturer at the University of the West of England in Bristol.

The first-step to treating cancer-related fatigue is to uncover and alleviate any underlying medical conditions -- such as anemia or an underactive thyroid -- that can cause fatigue-like symptoms, said exercise researcher Karen Mustian.

"There will still be a fair amount of patients dealing with fatigue after we get other situations under control," said Mustian, an assistant professor in the Department of Radiation Oncology at the University of Rochester School of Medicine. She was not involved in the review.

"I think it's safe to say at this point that the sort of generalized guidelines of walking 30 minutes a day three to five times a week generally helps patients," Mustian said. "We can't say what specific doses are best. With the evidence currently out there, we can't say much beyond that."

Cramp said a more confident "exercise prescription" will come after experts understand what intensity, frequency, duration and kinds of exercise are optimal for people with cancer.

"I believe, in the future, exercise in oncology can play a role, as much a role as exercise plays in cardiac rehab, but we need to do the types of large trials, appropriately powered to answer these questions," Mustian said.

In the meantime, Cramp said the available evidence should help convince health policy makers that exercise therapists, physical therapists and exercise physiologists need to be a part of the treatment team to support people with cancer.

Journal reference: Cramp F, Daniel J. Exercise for the management of cancer-related fatigue in adults (Review). Cochrane Database of Systematic Reviews 2008, Issue 2.