Do You Really Need to Wait 30 Minutes After Eating to Go Swimming?

Next to “don’t fill up on bread,” one of the most pervasive adult admonishments to children is the warning not to head for a swim 30 to 60 minutes after eating. The particulars are vague, but some believe it involves getting stomach cramps because blood is being pumped to your arms and legs, not your gut, or the opposite—that the body is diverting blood for digestion away from your arms or legs, which will prompt you to sink in the pool.

But is it true? Do you really need to sit around for up to an hour after devouring a hot dog before swimming?

According to Duke Health, the theory doesn’t hold water. While eating does divert blood to your intestinal tract, it’s not enough to disrupt the function of your appendages. Swimmers may experience a minor cramp, but nothing that would endanger them.

The proof? At no point has any drowning death been attributed to swimming too soon after eating. Some endurance swimmers even consume food for energy mid-swim.

There is one thing you can drink before swimming that can raise your drowning risk, and that’s alcohol. According to the CDC, alcohol can play a role in up to 70 percent of water recreation-related deaths. Other causes include not being able to swim, lack of security fencing around pools, and not using life jackets.

It’s possible this myth originated from a 1908 Boy Scouts handbook, which cautions that swimmers should wait after eating before taking the plunge. The belief was that digestion and exertion would somehow be in competition with one another for blood and oxygen, causing the body to cramp. Like a lot of well-intentioned medical advice at the turn of the century, it doesn’t stand up to scrutiny.  

Have you got a Big Question you'd like us to answer? If so, let us know by emailingbigquestions@mentalfloss.com.