Parents the world over warn us that eating before executing an epic belly flop into the pool results in debilitating cramps that impede our ability to stay afloat. When we do indulge in some poolside grub, they demand we wait at least 30 minutes before diving into the deep end—that way, our stomachs have some time to digest that over-sized burger so we can avoid the crippling agony it allegedly causes, and our subsequent inevitable drowning.
Now, this belief is somewhat grounded in science: When we eat, blood in our muscles flows toward our digestive organs to aid with digestion, and since muscles tend to cramp when their blood supply is curbed, you can see how overprotective parents might think a belly full of burger could prevent their child from staying above water.
However, the simple truth is that the blood shifted during digestion is nowhere near enough to have any real impact on our muscles. The Red Cross even published a study exploring this exact phenomenon, and they concluded that “eating before swimming is not a contributing risk for drowning and can be dismissed as a myth.”
Told you, mum.
In fact, snacking before swimming is probably a good idea. “It’s actually better to eat something before these physical activities so your body has enough fuel to power through them,” explains nutritionist David Friedman, author of Food Sanity: How to Eat in a World of Fads and Fiction. “Now, this doesn’t mean you should scarf down a giant pizza before running your next 5k—you need to eat sensibly and avoid overdoing it. Eating a combination of healthy carbohydrates and protein will give you sustained energy during your next swim or exercise.” He specifically suggests noshing on a piece of wholewheat toast with almond butter or a handful of mixed nuts with fruit — you know, that stuff you definitely always find on the poolside menu at a resort.
Light exercise, like wading in the pool, also helps with digestion. As dietician Liz Weinandy says, “Our gastrointestinal tract and the pancreatic and digestive enzymes our body produces are designed to digest food during the day, when we’re able to quickly burn them off by moving about.” Dana Hunnes, senior dietitian at the Ronald Reagan UCLA Medical Center, seconds this notion: “Light physical activity after a meal, including walking and possibly swimming, is good for digestion and helps to move food through the digestive tract.” In which case, perhaps following that hot dog party with a quick swim is for the best.
So go ahead and slam some chow before sailing off the diving board. But maybe ease up on the front flips — no word yet from the scientific community on how eating before doing some radical aerial maneuvers might play out.