New research suggests that a brisk walk or a slow jog on a regular basis may be the key to improved cancer treatments.

Researchers at Kansas State University found that moderate exercise on a regular basis enhances tumor oxygenation, which may improve radiation treatments in cancer patients.

"If we can increase the efficacy of radiation treatment, then the patient's prognosis is enhanced," researcher Brad Behnke said in a statement. "An intervention like exercise has almost universally positive side effects versus other treatments that can have deleterious side effects. Exercise is a type of therapy that benefits multiple systems in the body, and may permanently alter the environment within the tumor."

The National Cancer Institute at the National Institutes of Health recommends exercise for cancer patients and cancer survivors, but little research shows what happens within the tumors during such exercise.

"I became interested in finding out what happens within the tumor during and after exercise as a means to enhance treatment outcomes," Behnke said.

For the study, Behnke is using prostate cancer tumor models to find ways to enhance oxygen delivery to tumors.

"If we manipulate all the systems in the body -- the lungs, the heart and the blood vessels -- with exercise, we can take advantage of the dysfunctional vasculature in the tumor and enhance blood flow to the tumor," Behnke said. "The tumor becomes the path of least resistance for the elevated cardiac output of exercise, which results in a substantial increase in tumor oxygenation during and after exercise."

However, it seems that the key is moderate exercise. Too little exercise may have no effect, but too much exercise may have a negative effect and may shut down blood flow to the tumor region or impair the immune system, Behnke explained.

Moderate exercise is an activity that uses 30 to 60 percent of someone's aerobic capacity, Behnke said. The activity is nonstrenuous and is something that most people can perform, such as a brisk walk or a slow jog.

"There really aren't any negative side effects of moderate-intensity exercise," Behnke said. "Exercise is often prescribed to improve the side effects of cancer and treatment, but what exercise is doing within the tumor itself is likely beneficial as well."