In women, but not men, the exercise also helped to improve heartburn.
Sinh said she can't explain the mechanisms behind either the weight loss or the exercise, or why the exercise seemed to help only women. Although the study found a link between weight loss, exercise and GERD, it did not establish a cause-and-effect relationship.
While the use of heartburn medications is common, Sinh said she can't say if the men and women improved enough to go off medication, since she didn't track those results. Only about 5 percent of the men and women were on heartburn medications in the first place, she said.
One expert said the study had some strengths.
To start with, a relatively large number of people were studied, said Dr. Lauren Gerson, an associate professor of medicine and gastroenterology at Stanford University School of Medicine.
Besides just asking patients to report symptoms, she said, "it would be useful to have pH studies [done to evaluate GERD] to document improvement in overall pH scores after weight loss."
Even so, she said, the findings echo those of an even larger study, published in 2006, that found that weight gain -- even in those with normal weight -- was linked to new heartburn symptoms and weight reduction was linked to a decline in symptoms.
Whether weight loss can help those with heartburn discontinue reflux medications remains an unanswered question, Gerson said.
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.