Sodium? Potassium? Water? Electrolytes? I’m confused!!!

This is an article I wrote for my running club newsletter back in July 2008:

Sodium? Potassium? Water? Electrolytes? I’m confused!!!

When I was growing up and playing tennis in a very small town in the Philippines, whenever a tennis player started to get leg cramps, somebody would always ask to get some salt for that player to consume. I don’t know if it really helped or if it did, how long it took to relieve the cramps. At the time it was common belief that salt helped with leg cramps. Fast forward to the 80's and 90's. For one reason or another the pendulum had swung to the other end of the mineral spectrum and the so called more knowledgeable people were saying, take more potassium to prevent or relieve cramps. So they started serving more bananas during marathons. Here we are in the newmillennium and researchers have found that the common belief in the 60's and 70's and maybe a few more decades before that, was correct in the first place: that lack of sodium was the cause of leg cramps. Who knows? Maybe in a few years they will say that lack of another mineral causes cramping. This was even before the word hyponatremia was known except for people who worked in the medical field. (Hypo=low, Natremia(Na+)=Sodium). And now the question of electrolyte replacement drinks, bars, gels, shots, blocks. Once again in
the 80’s and 90’s you would often hear the tip:“drink early and drink often” during a marathon. Nowadays, it’s not necessarily true anymore,
because if you are running a marathon about 3 hours and beyond and you are just drinking mostly water to rehydrate, you are in danger of
getting hyponatremia. In other words, the water you kept drinking early and drinking often washed out the sodium from your blood through sweat. And this is the reason why we are seeing more salty energy replacement products in the market for endurance athletes. In brief, salt consumption retains water to prevent dehydration and cramps and also helps to avoid hyponatremia. A question came up at the Clif presentation on June 28,2008. Should one drink half electrolyte drink and half water during a marathon? Again, this was the common advice in the 80's and 90's and the reason being so that you don’t get an upset stomach from drinking pure electrolyte drink. All I can say about that is, drink and eat in a marathon what you drink and eat during training.