NEW YORK, Sep 08 (Reuters Health) -- Physical exercise has positive effects on cancer patients' quality of life, leading to improvements in both physical and psychological health, according to a team of Canadian researchers.
"Cancer patients are likely to experience a lower level of physical and psychologic functioning that may persist even after treatment is terminated," write Drs. Kerry S. Courneya of the University of Alberta and Christine M. Friedenreich of the Alberta Cancer Board in Canada. They noted that nearly 8 million Americans have a history of cancer.
To find out if exercise programs can improve the physical and mental well-being of these patients, the researchers analyzed 24 studies of exercise in cancer patients, published between 1980 and 1997. The studies included patients with a variety of cancers, mostly at early stages. Some exercise programs were started during treatment, while others began when cancer treatment ended. All programs involved aerobic activity for at least 20 minutes, 3 to 5 days per week.
Taken as a group, "the studies have consistently demonstrated that physical exercise following cancer diagnosis has a positive effect on quality of life including physical, functional, psychological, and emotional well-being," concluded Courneya and Friedenreich. They reported their findings in the Annals of Behavioral Medicine.
Physical benefits of exercise observed in the studies included lung capacity, muscle strength, flexibility and increased energy, as well as reduced nausea, fatigue, pain, and diarrhea. Blood markers and the activity of anti-cancer cells also improved in patients who exercised, the researchers report.
Psychological benefits included increased feelings of competence, control, and self-esteem, improvement in symptoms of depression and anxiety, and greater satisfaction with life.
The authors note two cautions, however. First, they point out that some cancer patients may require close medical supervision during exercise, and not all are able to exercise. Second, though the results of these 24 studies are strong, more research needs to be done, using larger groups of patients with a greater variety of cancers and stages. More specific research into the best kinds of activities and programs is also needed.
