Growing up, I always heard the old wives' tale: You have to wait approximately 30 minutes to swim after eating, or you'll be inflicted with terrible cramps, and drown. The amount of time seemed to change, however, from 30 minutes to 45, to even an hour.
I remember summers spent with my face in my hands staring at the clock after eating a hot dog. A quick Google search, however, will tell you that this myth is a little dramatic, that even if you were to get cramps, you wouldn't drown from them. That makes sense to me, but I still wanted to see if I would get those cramps from swimming after eating. Why? For science.
The Preparation
I figured that I should try the most extreme scenario possible, so I ate a huge meal — I'm talking seriously, huge.
After I finished eating, I felt nine months pregnant with a food baby. I barely wanted to walk, but I waddled up to my pool anyways.
Here Goes Nothing
I got into the water. I immediately felt a little bit of relief after I was submerged. It must be the whole zero gravity thing. I started to hop around in the water, to prepare myself for the rigorous exercise I was about to endure.
I started doing flips.
Then, treading water.
And finally, swimming laps.
I didn't feel like I was cramping, but I definitely felt uncomfortable, and a little nauseated. I tried to keep going, but I was out of breath, my heart was racing, and yeah, I definitely needed to throw up. I got outside of the water so I wouldn't spew in the pool. Luckily, I calmed down. I was going to go back into the water, but I figured I'd done enough for science.
So to conclude, there were no cramps, but I wouldn't recommend this experience to anyone else.
Where This Myth Came From
So, if I didn't get cramps doing the most extreme version possible of swimming after eating, where did this myth even come from? Snopes has traced this myth as far back as 1908 to a boy scouts manual, titled "Scouting for Boys."
Also, according to Women's Health, the blood flow to the stomach to aid in digestion is interrupted during exercise by redirecting blood to the muscles, which then can cause cramps. OK, so the cramp part is technically possible, but the drowning part of the myth seems like it sprung from the false belief that cramps were certain to occur during exercise after eating, and the most dangerous place to get them would be in a swimming pool.
The Problem is Exercising on a Full Stomach
It's clear that the real problem here isn't the water, but the swimming. Is it safe to exercise on a full stomach? Working out on a full stomach can lead to nausea (can confirm) or side stitch (like a stomach ache on your side). Oh god... Side stitch. Flashback to PE!
Eating foods high in fat and fiber especially put you at risk for side stitch, because they take longer to digest. It gets worse than cramps, however, because apparently, exercising on a full stomach can cause exercise-induced anaphylaxis. This is basically where your body has an allergic reaction to exercise. It's pretty rare, but can be triggered by eating common allergens or certain combinations of food before you exercise. So yeah, that sounds pretty terrifying.
To Conclude
As long as you're not going crazy or trying to get a workout in, go ahead and jump in the pool after you eat because swimming after eating is totally fine. If you start to cramp... stay calm and get out of the water and I promise, you won't drown.