Other studies have found that fatigue interferes with daily activities for about one third of cancer survivors. And fatigue can become a self-perpetuating cycle. "The less you do, the more fatigued you are," says Kiecolt-Glaser. Yoga seems to be a way to break that cycle. The study was published online in the Journal of Clinical Oncology.
Researchers recruited about 200 women for the study, all of whom had completed cancer treatment within three years. They ranged in age from 20s to 70s. The class included a series of very gentle stretching and strength-building exercises as well as breathing techniques.
"It's relaxing and refocuses the body," Sue Cavanaugh of Columbus, Ohio, a study participant, said. She says yoga has not only helped with fatigue, it's also helped her regain some of the lost mobility in her right arm.
"I'm happier because I can do the things I like," Cavanaugh says, including working with large installations in her work as an artist.
Earlier studies of yoga for cancer patients and survivors have found that yoga helped reduce distress, anxiety and depression, and had a moderate effect on fatigue and quality of life. But a Cochrane review of studies looking at the broader issue of cancer and exercise found that more vigorous exercise produced greater reductions in fatigue and improvements in quality of life. Exercise also may reduce the risk of cancer recurrence.
The Cochrane review also points out the biggest problem with doing randomized controlled trials of yoga: you know if you're doing it. That could bias people's perception of benefits.
"We're getting [breast cancer survivors] on bikes, on treadmills and training them like athletes," says Lee Jones, a radiation oncologist at Duke University's School of Medicine who studies the effect of exercise on cancer patients. Fatigue is a hurdle for lots of survivors, he says. "But if you actually prescribe exercise, they can exercise, and pretty vigorously."
Yoga can be a complementary form of movement to aerobic exercise, Jones says.