Researchers from the Medical College of Georgia report that news in Obesity's November edition.
Catherine L. Davis, PhD, and colleagues studied 100 overweight children age 7 to 11 in Augusta, Ga.
The researchers randomly split the kids into three groups.
One group got 40 minutes of supervised aerobic exercise -- such as tag, basketball, soccer, or jump rope -- every day for about 13 weeks.
Another group got 20 minutes of the same sort of daily aerobic exercise.
For comparison, kids in the third group weren't assigned to get any aerobic exercise; but they were free to continue their usual activities.
After about 13 weeks, the kids' parents completed a follow-up survey on their child's snoring and other sleep-related breathing problems.
Both exercise groups showed a similar drop in snoring.
But, kids assigned to exercise at least 40 minutes a day showed the biggest overall improvement in sleep-related breathing problems.
The improvements didn't depend on the kids losing weight. The results weren't related to changes in the children's BMI (body mass index), a ratio of weight and height.