Exercise is more effective than usual care for patients with cancer-related fatigue, according to an article in Issue 2 (2008) of the Cochrane Database of Systematic Reviews.

"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 Professor Fiona Cramp.

The meta-analysis examined 28 studies that lasted anywhere from 3 weeks to 8 months, but the typical intervention lasted 12 weeks. Many studies measured the effect of walking or stationary bike riding, but length, type and intensity of exercise varied widely across the studies. The researchers pooled data from more than 2,000 people living 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, of the Department of Radiation Oncology at the University of Rochester School of Medicine.

"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."

"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.