Men who get a moderate amount of exercise during radiation for prostate cancer are better able to cope with the fatigue the treatment can cause, researchers from Scotland report in the journal Cancer (Vol. 101, No.3: 550-557).

Though fatigue is a commonly recognized side effect of chemotherapy for cancer, radiation therapy can also make patients tired. Exercise is often recommended to patients on chemotherapy as a way to reduce the fatigue from treatment; the Scottish researchers, from Ninewells Hospital and Medical School in Dundee, wanted to see if the same prescription could help patients on radiation.

They studied 66 men receiving external beam radiation for early stage prostate cancer. Half the men were assigned to walk for about 30 minutes several days a week, while the rest were told to go about their normal activities, but rest if they felt tired. The men answered questionnaires about their fatigue before beginning radiation, after a 4-week course of radiotherapy, and 4 weeks after the end of treatment.

Before starting radiation, there were no differences between the two groups in levels of fatigue. After 4 weeks of radiation, however, men who were not told to exercise reported feeling more tired than before treatment, while those who were walking regularly reported no change in their fatigue level. Four weeks after treatment, men who were exercising still reported less fatigue than those who were not.

The men in the exercise group also had better physical functioning than their counterparts. All the men were asked to take a fitness test (walking at different speeds for a period of time) before beginning radiation and after the 4-week treatment. Men who did not exercise during treatment showed no real change in their fitness level. But the men who walked did improve: they were able to walk 13% farther in the given period of time.

Those findings aren't surprising, said Anna Schwartz, FNP, PhD, FAAN, an expert in physical activity during cancer treatment who was not involved with the research.

Radiation tends to cause fatigue that gets worse over time as the effects of treatment accumulate. Exercising can help counteract that trend, she said.

"Almost all patients feel better if they get up and move around a little bit," said Schwartz, who is a research associate professor at the University of Washington in Seattle. "People who exercise stay stronger, fitter, and actually get faster and stronger during treatment. So they are more physically fit and don't experience the physical decline and debilitation that most patients suffer through."

The researchers, in fact, speculated that men who did not exercise during treatment may have actually lost muscular conditioning, making everyday activities more difficult, and causing greater fatigue.

Encouraging prostate cancer patients to exercise could not only help them cope with the fatigue of radiation, the researchers say, but also could have long-term health benefits.

Schwartz agreed. "It should be the advice that all cancer patients receive," she said.

Exercise may be particularly helpful to men receiving hormone therapy for prostate cancer, she added, because it can help counteract the muscle loss and bone thinning hormone therapy can cause. Walking is a good choice because it's good for the heart and the bones and helps patients maintain mobility.

Even small amounts of exercise can help, Schwartz said. Someone who is too incapacitated, out of shape, or sick to walk 10 minutes straight can try walking 5 minutes in the morning and 5 in the evening. Even walking around the living room is a start. Bedridden patients can ask a physical therapist or other professional for exercises to do in bed that can help them retain some muscle tone.

The important thing is to do something, Schwartz said, even when fatigue sets in.

"Patients tell me all the time the most important time for them to exercise is when they feel their worst," she said, "but it's a balancing act. If someone feels worse when they exercise, they should rest.

"But if you keep saying I'm too tired to exercise today, and tomorrow, over time you start to get the debilitating effects of not using your body."