Can exercise treat cancer?
On a recent Wednesday night, Cindy Gerstner, 42, strapped her feet into a rowing machine and began gliding back and forth with all the energy she could muster.
This wasn't just a workout for Gerstner, whose stage 4 breast cancer has spread to her brain, lungs, bones and liver. It was a 40-minute dose of medicine.
"It's part of my treatment plan," said Gerstner, a member of Recovery on Water, a crew team made up of breast cancer patients and survivors who believe exercise is a powerful tool to help keep cancer at bay. "It's almost as important as chemotherapy in helping me stay on this earth as long as possible."
Once relegated to health clubs, exercise is muscling into its way into a wide variety of disease prevention and treatment plans. Physical fitness programs are already a staple of cardiac care. But though research is still in the early stages, there's encouraging evidence that consistent workouts can help with everything from cancer, autoimmune disorders and Parkinson's disease to alcoholism. University of Illinois scientists recently received funding for a study that looks at whether riding a stationary bicycle during treatment can help dialysis patients.
The burgeoning "exercise is medicine" movement is championed by dozens of organizations, including the American College of Sports Medicine, the Chicago Park District and cancer support groups. New national cancer guidelines urge both patients and survivors to exercise during and after treatment for 150 minutes per week, the same advice given to the general public.
Some big questions remain unanswered, such as what type and how much exercise is needed for what illnesses. In many cases, working out appears to relieve symptoms, but its impact on the natural course of the disease isn't known. And many physicians are cautious about prescribing something that can stress the body, especially for patients in the throes of a life-threatening illness.
"There's still a prevailing attitude out there that patients shouldn't push themselves during treatment," said Kathryn Schmitz, an associate professor of epidemiology and biostatistics at the Abramson Cancer Center at the University of Pennsylvania School of Medicine and lead author of the new guidelines.
Schmitz acknowledges that exercise is a stressor on the body but said resting too much also can have adverse effects. "Our message — avoid inactivity — is essential," she said.
If exercise isn't already a habit, of course, it can be intimidating. It's harder to do when you don't feel good. And "some people would truly rather take a pill," said Dr. Holly Benjamin, an associate professor and pediatric sports medicine specialist at the University of Chicago.
"But once they do it, so many people feel so much better."
In the past, breast cancer patients who had undergone surgery were told not to lift more than 15 pounds for the rest of their lives. Doctors also encouraged rest and limited exercise, fearing that strenuous effort would slow treatment or exacerbate conditions such as lymphedema, a painful swelling of the arms.
But Schmitz's groundbreaking work, published last year in the New England Journal of Medicine, reversed decades of cautionary advice by finding that slow, progressive weight lifting wasn't just safe, it could prevent lymphedema flare-ups.
Exercise can help people being treated for cancer cope with the side effects of chemotherapy, surgery and radiation, including fatigue and the loss of muscle mass. "It helps them get through treatment in better form," said David Nieman, director of the Human Performance Lab at Appalachian State University and the author of several textbooks on exercise as medicine.
A handful of observational studies, meanwhile, have suggested that exercise could result in a 40 to 50 percent reduction in the risk for recurrence of breast cancer, Schmitz said, though randomized controlled trials would be needed to prove a benefit.
For a few conditions, including Parkinson's disease, there's hope that exercise can affect the illness itself. In animal studies, exercise improved symptoms and increased the level of brain-derived neurotrophic factor, a chemical that protects cells.
"Exercise may modify disease by slowing the primary process of cell loss associated with Parkinson's disease," said Dr. Cynthia Comella, a neurologist at Rush University Medical Center, who is investigating the effects of regular exercise with a personal trainer on Parkinson's.
For treatment of pediatric rheumatic diseases, "exercise has been overlooked," said Dr. Bruno Gualano of the University of Sao Paulo in Brazil.
Traditionally, children with inflammatory diseases have been treated with drugs that can have side effects. But certain types of exercise can be safe and effective treatment for symptoms including muscle wasting, osteoporosis, insulin resistance, pain and fatigue. Scientists also hope to explore whether exercise can attenuate the systemic inflammation seen in such diseases.
Exercise's greatest strength may be that it can work on both physical and emotional levels. Wilmette's Mike Siegel was the father of three young children and his wife was pregnant with twins when he was diagnosed with chronic myelogenous leukemia in 1995.
"At first, exercise was my act of defiance," said Siegel, who rode his bike to work daily from Wilmette to Chicago despite the wretched effects of chemotherapy. "It was my way of saying, 'Cancer is not going to take me today.' It kept my mind and heart in the fight to save my life."
Though ultimately it was a combination of drugs that saved his life, Siegel calls exercise a critical part of his treatment during his 15-year battle with the illness. "It helped me keep my strength up and get me out of bed every day, despite continuous nausea and achy joints and bones," said Siegel, who recently completed the Ironman Wisconsin triathlon with his 18-year-old daughter.
Gerstner, an associate professor on leave from Columbia College, was diagnosed with stage 1 cancer in 2007 but said exercise was not discussed as a way to prevent recurrence. Now she's rowing as a way to keep her body strong so she can endure more of the treatment.
"I may be exhausted when I arrive (at practice) but I feel energized when I leave," said Gerstner, who has a 4-year-old daughter with her husband, Alfredo. "It also helps me feel 'normal' — that my body hasn't totally abandoned me via cancer, but that I can still exercise and push myself."