RFF#97 – There’s one time when you can guiltlessly add salt to your food…

…after you’ve exercised excessively and have consequently sweated excessively.

The story behind today’s post began two weeks ago when I played tennis for three hours…drank a lot of water…went to sleep…and woke up at 4:00am with one of the worst headaches of my life!!!!

You see, normally your blood has a balance of sodium [Na] and water [H2O] (in addition to many other things, but for the sake of today’s post we’ll just focus on the sodium)…


Balance of Sodium and Water

Note: Ratios are not to scale


But when you sweat, you lose both water and sodium…


Balance of sodium and water - after sweating


And if, like me, you exclusively drink water post-exercise, your blood steam will look like this…


Balance of sodium and water - after drinking water


This condition is called hyponatremia (hypo=low, natremia=blood sodium). The consequences of hyponatremia include dizziness, headache, nausea, and oh…did I mention death! For years I suffered from hyponatremia after playing sports. No one could tell me why, and I never figured out the problem until I took Physiology 302.

Sports drinks are the obvious solution. Me of course, having made a personal pledge to never drink caloric beverages, fell victim to my own good intentions.

However, while replacing electrolytes (such as sodium) is part of the solution, electrolytes alone won’t completely solve the problem. That’s part of the reason why sports drinks don’t exclusively contain electrolytes. And while they probably contain more sugar than you really need, sugar is nevertheless an essential ingredient.

That’s because on its own, sodium can’t pass through the cells of your intestine and enter your bloodstream. It needs to be transported. And one of the transporters that accomplishes this task is a sodium-glucose transporter, which means it needs both glucose and sodium to operate. Therefore, post-exercise, carbohydrate is needed to assist in the absorption of sodium.

Note: This diagram is highly simplified

Note: This diagram is highly simplified


While consuming a sports drink will get the job done, sports drinks are not your only option, anything that contains carbohydrate and sodium should do the trick (ex. crackers, juice, a pickle, etc.).

In conclusion, it’s kind of funny how so much of my work is dedicated to preventing people from suffering from having too much sodium, meanwhile I somehow manage to let myself suffer from having too little!! So as I sit here typing this story, after having just played tennis for three hours…rest assured, I’m snacking on a tiny bit of pasta and vegetables, to which I added a dash of salt!

Here’s some photos to lend cred to my story…

Since it's difficult to take a picture of yourself playing tennis, I opted for a shadow selfie.

Since it’s difficult to take a picture of yourself playing tennis, I opted for a shadow selfie.


I love those pink laces!

I love my pink laces!


–I learned about this fact from: Years of unpleasant experiences and my third year physiology professor Dr. French!


RFF#78 – Joseph Priestly discovered carbonated water in 1767

Joseph Priestly, not to be confused with Jason Priestly, was an 18th century theologian, natural philosopher, chemist, educator and political theorist.Though the discovery of “soda water” had little scientific value, Priestly called it his “happiest discovery”.

jj priestly

So how did the discovery come about? It was largely due to the fact that in 1767 he: 1) got a new job and 2) moved.

For starters, by getting a new job as a minister he had a lot more free time (to experiment and make discoveries) compared to when he was a teacher. But what was more important was the fact that when he moved to his new town, the official minister’s home was not ready. As a result, he stayed at another house which happened to be located beside a brewery.

Due to his scientific curiosity, it wasn’t long before he began conducting experiments in the brewery. He noticed that the vats of fermenting liquid emitted what he called “fixed” or “mephitic” air (what we call carbon dioxide), and he discovered that if he poured water between two cups over top of the vats, the water became suffused with the “fixed air” and acquired a “fizz”. Within days Priestly was discussing this new invention with colleagues and published a pamphlet describing it: Directions for impregnating water with fixed air, in order to communicate to it the peculiar spirit and virtues of Pyrmont water, and other mineral waters of a similar nature.

Here’s a picture of Priestly’s soda water apparatus:


Priestly was a “compulsive sharer” and he believed in the circulation and dissemination of ideas. So instead of protecting his invention and patenting it, he shared it immediately with everyone. Apparently the notion of withholding information for personal gain was unimaginable to someone like Priestly.  However, as a result of this “compulsive sharing”, a man by the name of Johann Schweppes would eventually patent a method of carbonating water in 1783 and Priestly would forever be dependent on financial patrons.

I learned about this fact from: Johnson, Steven. The Invention of Air A Story of Science, Faith, Revolution, and the Birth of America. River Head Books, New York: 2008. [By the way, a great read, I highly recommend it]

RFF#18 – Salt increases the amount of water that binds to meat…therefore, salty meat weighs more, and thus costs more

Have you ever wondered why there is so much salt in our food? There are a couple of reasons, and this one demonstrates that salt isn’t just there to add flavor and extend shelf life. Apparently it may also increase food industry profits.

—I learned about this fact from: He FJ and MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. Journal of Human Hypertension, 2009;23:363-384.