THE CLAIM -- Never swim after eating a meal.

THE FACTS -- Think of all the hours Americans will spend beside pools and lingering on beaches this summer, counting the minutes since their last meal to avoid violating a fundamental rule of swimming: never get into the water on a full stomach.

The only problem, according to experts, is that the warning is yet another old wives' tale that should be laid to rest. The theory is that the process of digestion increases blood flow to the stomach -- away from the muscles needed for swimming -- and leads to cramps, which increase the risk of drowning.

Dr. Roshini Rajapaksa, a gastroenterologist at the New York University School of Medicine, said that while swimming strenuously on a full stomach could conceivably lead to cramps, for most recreational swimmers the chances are small. And at least one study that looked at drownings in the United States found that fewer than 1 percent occurred after the victim ate a meal, she added.

But meals that include a drink or two are another story. In 1989, for example, a study in the journal Pediatrics looked at almost 100 adolescents who drowned in Washington and found that 25 percent had been intoxicated. One year later, a study of hundreds of drowning deaths among adults in California found that 41 percent were alcohol related.