LITTLE FALLS, N.J., July 1-It turns out that mothers were giving sound advice when they told their children to avoid swimming right after eating, but not for the reasons they thought.
While there is some validity to the old wives' tale that swimming, or any sort of strenuous exercise, should be avoided after a meal, it's not because of blood being siphoned from the intestines to the heart or exercising muscles. That's the myth of conventional wisdom.
"There's a shred of truth to it, but probably for different reasons," said Mitchell Spirt, M.D., director of gastroenterology at Century City Doctors' Hospital and a professor of medicine at the University of California at Los Angeles.
"When you swim, it's a particular exercise where you're horizontal and you don't want to be horizontal after eating because of gastroesophageal reflux," including heartburn and regurgitation. Patients are advised against lying down or sleeping soon after a meal for the same reasons, he explained.
It is true that blood is shunted from the stomach elsewhere to the body during any type of exercise, "but there is no (clinical) consequence to this," Dr. Spirt said.
Two to four hours is the preferred wait time before swimming in the pool or against the current, Dr. Spirt said. "What two hours does is it gives a good period of time to empty out the stomach."
Margot Putukian, M.D., director of athletic medicine at Princeton University, feels that four hours is the optimal waiting period. However, what a person eats and their fitness level should also be factored in.
Proteins digest more slowly than carbohydrates, she noted, which could affect how long a patient should wait before swimming. "If it's a sport drink or something mainly consisting of carbohydrates then you can probably exercise sooner than if it's a heavy meal with lots of protein," Dr. Putukian said.
For low-exertion, casual splashing around the pool or the beach, four hours of waiting may not be necessary, she said. Physicians, she added, need to individualize such recommendations on the basis of fitness levels and dietary intake.