In racing, you need a few things in order to keep moving forwards. I sometimes think of these in terms of “how long can I go without.” You can go a few days without food, a few hours without water. Nobody would think of doing a race stage of any length without both of these. There’s a third essential - often forgotten: salt. Salt is easy to overlook - most people are extremely good at conserving it. But if you race in the heat and are drinking plenty of water, there’s a good chance you’re heading towards hyponatremia (hypo meaning “too little”, natre "salt", and emia- meaning "in the blood”).
Hyponatremia is a tricky condition to diagnose in the field, it has a wide range of symptoms, many overlapping with other conditions. However, if left untreated, it is deadly. Slowly your body will pull salt from your tissues and muscles to keep your blood chemistry balanced. This can hide its effects for a surprisingly long amount of time, far too late to do anything about it. Salt needs to get back into your cells via your blood, and so what takes a few hours to leech out of each cell can take hours or days to recover. You can’t just drink a gallon of sea water and have your body work it out.
I have the dubious distinction of being one of the most well-known cases of hyponatremia - my disastrous bonk from the first episode of Eco Challenge: Fiji was largely because of hyponatremia. I thought I was supplementing salt, but I wasn’t consuming nearly enough for how much I was sweating. It took me days to slowly recover - and any time it was remotely hot, my body would shut down because it was so close to the edge. We didn’t have the proper salt supplements with us on course, but thankfully every day or so we passed through a TA camp. At those camps I ate a few packages of ramen, which obviously have a lot of salt in them. After that, I felt good for a while. Again, I thought I was supplementing enough, and I only figured it out after the fact.
Fortunately I now know that hyponatremia is not that hard to avoid - take a 500mg to 1000mg of salt (we love using Salt Stick - Use code BendRacing for 20%off) per liter you drink in the heat (note: this is referring to total weight of salt, not the weight of sodium as reported on the label). If you’re sweating it out, you’re probably losing the salt. If you’re peeing it out, you’re keeping it onboard. There is some recent research suggesting that sweating loses different amounts of salt per person, so you may need less (unlikely you'll sweat as much as me!). If your sweat-drenched clothes don’t wind up crusty with salt, you may be one of these lucky people! Some people like to mix salt into their water, but I prefer to keep my salt, water, and food pretty separate. Salt in gel-caps (e.g. SaltStick Caps is our preferred method), water as clean and pure as I can find it, and 4-hour fuel for my primary calories. I consume one or two gel-caps (usually each is 500mg of salt) per hour in the heat and or during strenuous exercise, I take a gulp of water every 15 minutes, and a big swig of four hour fuel every half hour or so. Keeping a schedule makes it much easier for me to keep track of it all. Let me know if you have any questions, happy to chat!
Oh! And, please use our code, "BendRacing" at this link for Salt Stick!
- Daniel Staudigel (also now known as "underwear Dan!"
Here's a fun photo I'll leave here- back in 2011 at our 2nd or third Motherlode Expedition Race!
