It was a hot summer day and Ashton and I were running one of our brutal 400m workouts that often made me express how scared I was, which typically prompted our coach, Harry, to respond, “Ahh you’ll be fine, Bri. It might hurt a bit but you’re not going to physically die.” Although I never died, sometimes it felt like I was going to, writhing in pain on the ground after the last set.
Ashton wasn’t able to finish the workout that day. This was the 3rd or 4th workout in a row that his calves cramped so bad he had trouble standing up. Harry was fed up and continually asked Ash if he was sure he was drinking enough, eating enough, etc. When all his responses were “Yes,” Harry took it upon himself to get to the bottom of it.
The next day, we were in a lab getting a sweat test done. This included us getting electrodes hooked up to our forearms, which pushed a chemical into our skin that caused the sweat glands to contract. Then a little sweat collection device was hooked to our forearms to collect the sweat so that a machine could measure the amount of sodium in our sweat. You can see the process here.
What we didn’t know was that not all sweat is created equal. When you sweat, you sweat out water and electrolytes, but everyone sweats out different amounts of sodium. This is actually genetically determined and has nothing to do with size, weight or gender.
What we found was that the level of sodium in my sweat was 798mg/L, which was on the average end, but Ashton’s was 1638mg/L! This means that for every liter of sweat Ashton lost, he would need to drink 4 of those big 32 oz bottles of Powerade to replenish it, which is tough to do when you’re trying to run a workout. He obviously wasn’t replacing the sodium, and this was causing his muscles to cramp. Very simply put, sodium (along with other electrolytes) controls muscle contractions by triggering nerve impulses. When sodium levels drop, the nerve signals go haywire and a cramp is triggered.
He started adding more salt to his food. While I do salt our food at home while cooking, we never eat processed foods, which contain high levels of sodium. So during the summer months when he knew he would sweat more, he’d add a bit more salt to his food and even added salt to his sports drinks. This completely solved his cramping problems.
Since I saw the massive impact that eating a bit more salt made on his workouts and performance, it made me curious if this could happen to athletes on the other end of the spectrum, the ones who didn’t lose a lot of sodium in their sweat but were replenishing too much with sports drinks or salty foods. I learned the same thing can happen: their muscles can cramp. This is because when you have an abundance of sodium in your body, it pulls fluids from the body tissues (muscles) into the blood to balance everything out. Now your muscles are dehydrated and you cramp. Crazy!
This latter example is similar to what seems to be happening in our world today: overconsumption of salt. If you eat too much salt, the kidneys have trouble keeping up with the excess sodium in your bloodstream, so the body holds onto water to dilute the sodium. This increases the total volume of blood in your blood vessels, causing blood pressure to increase. This means extra work for the heart and more pressure on blood vessels which can stiffen them and lead to high blood pressure, heart attacks, and strokes.
The Common Fix? “Put down the salt shaker!”
I never believed that people were consuming too much sodium due to their at-home saltshakers. And there’s proof!
In 1991, a clever experiment was published by the Journal of the American College of Nutrition. Researchers from the Monell Chemical Senses Center in Philadelphia identified the true source of America’s sodium problem. Sixty-two adults who used salt regularly were given pre-measured saltshakers to use at home for a week. They were asked to keep careful track of everything they ate and drank. To increase the reliability of the record-keeping, the Monell investigators spiked their saltshakers with a tracer that showed up in the participants urine. Through regular urine samples, researchers to see precisely how much salt the shakers were contributing.
There was hardly any sodium in the water they were drinking daily, so that was ruled out as a source. Some sodium occurs naturally in Swiss chard and spinach, but the participants would have had to gorge themselves on these foods for it to make a difference. The naturally occurring sodium in their meals contributed only a bit more than 10% of the total sodium they consumed in a week. As for the saltshakers, it delivered just 6 percent of their sodium intake. The remainder? More than 75% of the salt the participants consumed in a week came from processed foods — preassembled, precooked and prepackaged supermarket foods.
The Bottom Line
Whether you want to criticize this study and get into the fine details of how it was conducted, I think the point is fairly clear. We are eating WAY too many pre-made foods and not cooking enough of our own meals. Please stop eating processed and prepackaged convenience foods. Fresh, natural, homemade meals always taste so much better!
https://www.hsph.harvard.edu/nutritionsource/salt-and-sodium/sodium-health-risks-and-disease/ “Salt, Sugar, Fat” by Michael Moss