Imagine your perfect summer day: You sleep in late, make your way to the beach (or lake, or pool), and spend the rest of the afternoon alternating between napping in the sun, eating hot dogs, and taking a dip.
Outside of remembering to re-slather yourself with sunscreen, there's not a lot you have to worry about — except for that whole old adage about waiting 30 minutes to swim after you scarf down your lunch or have an ice cream cone.
What's the deal with this theory, anyway? Where did it come from, and do you really have to worry about it?
Where Does the 30-Minute Rule Come From?
The idea behind the 30-minute rule has always been that while your body is using blood to aid in the digestive system after eating, it won't have enough to adequately fuel your arms and legs while swimming, which could result in a cramp that would make it difficult for you to stay afloat.
While this might sound a little bit dramatic, it could happen, according to experts. "Minor cramping is a factor when it comes to swimming after eating," says Nora Minno, RD, CDN, a registered dietician and certified personal trainer. "It's especially a risk if you're planning a more vigorous swim, like laps in the ocean," she says.
Think of it like going for a jog on a full stomach — you might not collapse onto the ground, but you might get a stitch in your side and need to stop. But just because this idea is scientifically viable doesn't mean that it's necessarily a proven risk. According to an expert quoted in the New York Times, one study that looked at drownings in the United States found that less than one percent occurred after the victim ate a meal.
A Few Other Factors
Of course, there's more to all of this than just when you ate, Minno cautions. "Your size and hydration status can be a factor in cramping as well," she says. So making sure that you continue to drink water all day is important.
Speaking of drinking, another thing to consider is alcohol consumption. In fact, studies have shown much more of a link between drowning deaths and alcohol consumption. If you're considering a beer or a glass of wine before swimming, that might be something you should worry more about than whether you've had an ear of corn too recently.
The Final Takeaway
You already know how important it is to stay hydrated — especially if you're spending the day in the sun. And you also know to avoid alcohol consumption that could impair your abilities and judgment while swimming.
Does that mean you can eat anything and everything for lunch and then jump in the pool? Not quite. Minno recommends you avoid high-fat foods (sorry, french fries), and stick to a mix of protein and carbohydrates to have the best chance at feeling great all afternoon long.
Also, if you want to swim after your lunch (and we mean, like, really swim — not just standing in the pool while you read a book), it's not a terrible idea to wait. Or just bring a friend into the water with you just in case. That's more fun anyway, right?