It's advice parents have been giving their children for generations.
"When I was growing up, I remember my mother telling me, you know, not to go in the pool until it was 30 to 60 minutes after I had my last meal," says Dr. Michael Boniface, a Mayo Clinic emergency medicine physician.
He says the motherly advice had serious origins but may not be as helpful as once thought.
"We know now that really there is no scientific basis for that recommendation," Dr. Boniface says. "You may end up with some stomach cramping or a muscle cramp, but this is not a dangerous activity to routinely enjoy."