Have you ever heard of Hyponatremia? I hadn’t until I discovered why my body revolted on long mountain bike rides. Here is my story.
We had biked about 30 miles in the eastern Arizona desert and things had gone as planned. Steve and I had carried out our usual pattern on this ride. I rode fast for a couple of miles, and then found a good place to stop and wait. Eventually Steve came along and told me he barely avoided a couple of deadly crashes. We spent only a minute sharing ideas before Steve insisted we must move on. I then took off, and the cycle repeated.
As we approached the Gila River we came to a split in the trail. Steve, looking at his GPS, said he was not sure which way to go. “What do you mean,” I asked, irritation rising in my voice. “Left takes us up that mountain while right takes us down to the river. Surely you must remember which way you went!”
I began to get unreasonably displeased with my buddy. Not only had Steve done the trail the previous year … he had the track right in front of him on his GPS! “Well, when I zoom in I can’t tell if this is the track or a contour line.” He calmly stated.
We ended up going left, but soon ran into some people in an off-road vehicle who told us we were headed in the wrong direction. We turned around and quickly found the trail just before reaching the river.
The temperature seemed to rise quickly as we rode alongside the river and my legs and lower back began to burn and ache with fatigue. I had become more and more cranky ever since we had taken the wrong turn, cussing each rock I encountered, as if it had intentionally jumped out and hit my tire. Not only that, I also found myself stumbling a little while trying to get back on my bike when I had lost balance. Then my legs began to cramp up.
After a couple more miles Steve suggested we take a break and I complied, grumbling about wasting time. As I slowly downed an “energy” bar (I seldom feel hungry on a ride), Steve offered me some salt tablets. He said he had been doing some research and had found that the most important factor in long distance exercise was maintaining proper levels of salt. “Most people will tell you potassium or carbs are the key, but my sources tell me it is sodium.” The medical tern for low salt levels is Hyponatremia.
I took the salt tablets after finishing my bar and soon we were back on the trail. The last part of the trail necessitated climbing a couple of real steep hills which we both ended up walking. As we pushed on I was suddenly aware my legs were no longer aching as bad and my attitude had improved significantly. By the time I reached the end of the 42 mile jaunt I felt great!
You might be thinking maybe I was dehydrated … but I had drunk plenty of water along the way. It could have been the “energy bar” kicking in. But I have tried eating regularly on the long rides, yet still found myself very irritable and cramping up. Steve had said I go into “Survival Mode.”
My mother, who just turned 86 this January, has developed a form of Hyponatremia called Diabetes Insipidus, where her body cannot seem to retain salt due to low levels of Antidiuretic Hormone (ADH) produced in her brain. Her symptoms almost exactly mirror what I felt on my long rides … headache, fatigue, irritability, and muscle pains. All this due to low sodium levels.
The last time I experienced Hyponatremia this past summer when I was trying to find a way around a local reservoir.
I had only biked a couple of miles but the temperature on the trail was excess of 100 degrees (don’t ask me why I was riding in that heat). After a short climb,and sweating like no other, I decided to sit under a tree. I was disgusted with running into No Trespassing signs. I was ready to quit looking for a route and go home. I had drank plenty of water from my Camelback but was feeling a little dizzy and my legs muscles were burning.
Then I took one of my 20 ounce bottles of water (with a scoop of Scratch dissolved) and drank the whole thing. Five minutes later I started feeling better. After a couple more minutes I decided to keep looking for a way to circumnavigate the lake. I had also decided to keep drinking the Scratch periodically. Once back on the bike I actually started feeling stronger! I rode thirty more miles that day, and felt great even though I never did find a way around San Vicente.
I think Steve was correct. When on a 30 to 50 mile ride or special situations when I sweat a lot, I need more salt to keep functioning properly.
Researchers at Rice University have this to say about Hyponatremia:
It is best if you strive to get your sodium from both sports drinks and salty foods — as opposed to salt tablets — for two reasons. Salty foods stimulate thirst, and it is possible to ingest too much salt with tablets but very difficult with food. If you don’t think that your food and sports drink is providing enough sodium, then consider salt tablets. Make sure you know how much you are taking!
What foods are best?
Ideally, foods consumed during a long race should be low fat, low protein, high carbohydrate, and provide a source of sodium. You need water, carbohydrates, and salt to survive a long race. For convenience, I have listed a few foods and sports drinks and their respective sodium content. You’ll need to experiment and find the combination that is best for you. Get used to reading the FDA labels.
Personally, I don’t like swallowing salt tablets (when I actually remember to take them). Sport drinksare helpful … since the salt is in the drink (and I do getthirsty), so I don’t have to remember to take my salt. But regular Gatorade is too sweet … and I can’t stop drinking it! Drinking a whole bottle of Gatorade each time I get a little thirsty means I run out about half way through the ride (which I have actually done)!
Gstorade 2 (G2) is a little less sweet, has but has artificial sweeteners … which always seem to eventually cause cancer with prolonged use.
Skratch is made from ground up fruit and has worked the best for me. Scratch is not overly sweet, yet has more than 1½ times the sodium than either of the Gatorades.
I do like eating most salty foods, my favorite being the Sweet and Salty Peanut bars (140 mg of salt for one 1.2 ounce bar) from Nature Valley. And when I am done riding I always crave the Lay’s Classic Potato chips and a large cup of iced drink … salt, carbs, and liquid.
Now, I am not a registered dietitian or an exercise physiologist and I am not saying I have a solution for everyone, but for long, hot rides I have found ingesting salt on a regular basis really seems to help me.
*Note- I did the same Arizona Ride a couple of weeks age, drank plenty of Skratch, and felt great the entire way!