Contrary to a long-standing tradition, you don't need to wait for one full hour after eating before heading into the pool.

Parents often tell their children to wait 30 minutes or one hour after having a heavy meal before they swim.

The advice that has been handed down over generations doesn't hold water, said Dr. Richard Fedorak, head of gastroenterology at the University of Alberta Hospital.

"That's a myth, and we need to myth bust," said Fedorak.

The old wives' tale is based on the mistaken idea that the stomach will take away some of the oxygen needed by our muscles during swimming.

In reality, people have more than enough oxygen to supply both the stomach and their skeletal muscles.

Dr. Richard Fedorak

It is therefore unlikely that diving into the water soon after a meal will leave someone in so much distress that they drown.

"The simple average meal isn't going to affect your ability to get into the water," Fedorak assured.

Competitive swimmers, though, generally shouldn't eat a large meal before an event because there's a risk the cramps could hinder their performance.

While eating is OK before a swim, drinking is not advisable. A study published in the journal Pediatrics found one-quarter of teenagers who drowned were intoxicated. A similar study on adults found 41 per cent of drowning deaths involved alcohol.