Outdoor Survival Guide – By Dr. Alan Christianson
Hey, there! Dr. Alan Christianson here. This is one of my favorite topics: how to survive outdoors. This will not be about food and shelter, but about managing the sun, your calories and staying hydrated. They are all pretty important. I just saw a patient who works outdoors and is having severe migraines, suffering from exhaustion and cramping at night. He was drinking a lot of Gatorade, trying to keep himself hydrated, but not eating much for breakfast. I think we’re going to see his symptoms were caused by how his blood sugar, electrolytes and hydration were playing out. If you consume too much liquid and too little electrolytes, you can make things worse. If you consume a lot of sugar, it makes a lot of things worse. That is all Gatorade is. There is really not much use to that stuff at all. You can do better in so many ways.
What are the best ways to manage sun exposure? You want to have some type of physical barrier between you and the sun for some bulk of the time. There are many nice clothes and hats that keep your body from getting clammy and do a good job blocking the sun. We are still not sure how well sunscreens protect. They will keep you from burning, but there is not strong evidence they protect against skin cancers. I am in a shaded area on purpose here. My Irish skin is just ready to freckle, burn and form cancers (long term), so I have to watch that. Big-brimmed hats make a huge difference. Longer sleeves and collars are also a good thing. On the areas you can’t cover, use a sunblock instead of a sunscreen. So, what is the “block” in a sunblock? It is a mineral. Titanium and zinc have been used a lot. The old zinc was the white stuff on the nose of the lifeguard. They now have versions of zinc that are clear. Many good sunblocks are zinc-based. Apart from covering with clothes and a sunblock, minimize exposure. In speaking about sun exposure, the question comes up whether you can make your own vitamin D or not. I wish sun exposure was a consistent way to get Vitamin D, but it is not. We think the cycle is this: the oil our skin uses to absorb Vitamin D takes many days to mature, and because of regular showering and bathing, we cannot assimilate it that well. Many people, who have too much sun exposure from working or training outdoors, are just as low in Vitamin D as anyone else, until they start taking it.
Let’s talk about the calories you need to survive the outdoors. Do you need extra calories? What about the Gatorade and the sugar in it – do you need those calories? If your goal is performance (if you’re in a race), one strategy is to get a certain number of calories per hour (maybe a few hundred). Apart from that, I don’t see a benefit. Eat as you would normally. Have a good meal. Have some snacks, if you are used to them, but you do not need to change your calorie load. You do not need sugars to help you when you’re being active. Sugars actually make you more apt to lose fluid.
Hydration is a double-edged sword. If you go for a long hike or work outside all day, and don’t drink a drop, there is no doubt you will wreck yourself. On the other hand, you can over-hydrate. How does that happen? When you are active, your blood is going to your muscles because that is where you need it. You aren’t cranking a lot of blood into the intestinal tract. You can drink lots of water, but you cannot absorb all the water. So, if you are drinking faster than you are absorbing, you are making a big pool in your stomach. This pool is going to pull salt into it. So, not only are you not absorbing the water, but it is also taking electrolytes out of your bloodstream. It is tragic to hear about fatalities on a marathon or an Ironman triathlon. It is almost always someone who is taking a long time out there and hydrating very aggressively. They may have had 5 or 10 hours to drink tons and tons of water, and it was more than they needed. Salt was pulled out of the bloodstream and rendered their heart unable to beat properly. So, over-hydrating is a real danger. So, how do you not over-hydrate but not under-hydrate at the same time? Thankfully, this one is simple. It shocked me how narrow the absorption range is when you are exercising. The old advice was to look at how much you were probably going to lose, and drink that much. This is not right. You cannot drink that much. If you drink as much water as you are losing, you are over-hydrating because you lose water faster than you can absorb it. Whether you are a petite woman, doing a light workout on a moderate day, or a huge guy getting your butt kicked going up Pikes Peak on a hot day, the amount of fluids you can absorb is extremely narrow. We think it is about 20-26 ounces per hour. You don’t want much less or much more than that. Most water bottles are about 20-24 ounces (Buy the type you can refill and not the ones you throw away). There are also packs you can use. I love CamelBaks when I am doing things that are better hands-free. You can get most of those in increments of 2 or 3 hours’ worth of water. So, think about 20-26 ounces per hour. Do not fall behind that amount, and do not go ahead. It is also really good to pace the total amount. Have an approximate sense of consuming some water every so often, so you are halfway through your water when you’re halfway through your activity. Keep on pacing it so you’re getting it at a steady stream. That is not only best for absorption, but will also keep you alert and energized.
The last thing about hydration is the consideration of electrolytes. They are important, and there are a lot of them. The biggest electrolytes are sodium and potassium. Some others, like calcium, magnesium and chloride, are minor but still important. Sodium is a paradox. The saltier your diet is, the more salt you lose, and the more salt you need. If you are on a lower sodium diet, you actually need less salt and can be more active without being dependent on consuming a lot of salt. So, you are better off not being aggressive with your salt intake all the time. This way, you lose less salt, are able to manage your salt better and can recycle it, making it more effective. When doing several hours of activity, most of us really don’t need added salt, assuming we are on a lower salt diet. If you have a high salt diet, you should change that. There are electrolyte replacements that can work. Endurolytes is one I like, but lowering your salt intake is best. The other big electrolyte is potassium. If you are doing well with eating fruits and vegetables, you will have plenty of potassium. Bananas always pop into mind, but all types of produce (especially greens) are very high in potassium. If you are out for several hours, it is good to get some potassium as you are going. In those times, my very favorite source is coconut water. There is coconut milk, which is the thick stuff for curry. There is a coconut beverage that serves as a milk replacement. Then, there is coconut water, which is really tasty. You can put a few ounces in your water bottles and your CamelBak. Just rinse them out a bit afterwards. Coconut water is very light and neutral in taste and has a good amount of potassium, as well as magnesium and chloride. If you are someone who loses a lot of salt, you can also add a few pinches of salt, and you’ll do fine with it.
So the take-home message is keep yourself covered. Get 20-26 ounces of water per hour. Throw in some coconut water and maybe a few pinches of salt, have a lower sodium diet overall, and you will do great.
Stay active! Have fun, and we will talk again real soon.