Fueling Up On The Mountain: How To Eat At High Altitude
You’ve felt it. You’re on top of the mountain and you breathlessly declare, “Ah, there is no air up here—I can’t breath!” Your heart is racing, you’re shivering, and you haven’t even started your run. Well, guess what, our bodies don’t cope well with being cold and high. Unlike hot weather where the goal is to decrease core temperature, in cold weather our bodies try hard to increase core temperature. We shiver to increase our metabolic rate as our blood vessels work hard to increase our core body temperature and pump blood via our vessels to our extremities. Meanwhile our body is in total freakout mode from the lack of oxygen in the air. Our heart rate is rising, trying to pump more and more red blood cells anywhere it can so it can get oxygen to our muscles. So yeah, we’re breathing rapidly, shivering and we haven’t even begun to ski.
Altitude is an energy sucker.
Trying to perform at altitude is tough. When there is no oxygen in the air, the first thing that happens is that our heart rate rises and we begin to breathe faster. Even when we’re not exercising, and we’re just hanging out at the top of the mountain, our breaths become rapid and our heart rate rises. The lack of oxygen in the air means less oxygen in our blood. Our bodies scramble to get oxygen to the tissues to get them to work. VO2max is the maximal oxygen consumption your body can reach. As elevation increases your VO2max decreases 6% every 1000 meters. This means less oxygen to your muscles and, consequently, decreases in your performance. Now imagine that you’re at the top of Vail. You’re now at about 15% deficiency. Get to the top of the mountain and your reduction in VO2max can be upwards of 20-30%. Trying to breathe with that much deficiency, while your heart rate is pumping in extreme exercise, takes a lot of energy. Plus the rapid breathing means more moisture lost through the mouth and an increasing risk of dehydration.
Carbs Love The Cold Oxygenless Air:
In normal temperatures our bodies strain at high altitude, but when we’re exercising and it’s cold it gets even harder. When your body is working hard, it needs more energy. This means at altitude your muscles will be craving glucose. Your heart will need it to pulse and send blood around your body, while your muscles need it to contract and flex. Like the cold, at altitude we are prone to bonking. If you’re going hard out on the mountain, we recommend having about 60-100 grams of carbs per hour. Metabolism increases at altitude. Add cold weather and your body will be working overtime so you don’t need to worry about caloric intake. Focus on not bonking and keeping your energy up. Unlike other animals that can easily burn body fat for energy and heat, we can’t. Once we’re cold, we’re cold. In order to get more energy to create body heat, we burn carbs. In the cold, you’ll burn even more carbs because your body is under a lot of stress to maintain basic functions and keep it at that precious 98.6 degrees. You may feel like you’re not doing much, but your body is burning through precious carbohydrate stores. Before you know it, you could hit the wall so always carry some gels, high-carb bars, or chews in your pockets. Make sure what you carry is cold-friendly and easily digestible. When hypoglycemia hits we can become very loopy, confused, and irritable. Sometimes, figuring out how to open a simple pack of chews can be a task unto itself. We find gels like the SiS Go Gel and chews like ProBar Bolts work the best, as well as whole foods like AllGood Provisions Dried Cherries and Nuts. Honey Bunchies can also be kept well in a pocket, are a welcomed treat, and worth risking cold fingers.
Drink the altitude away.
When it’s hot, we know we need to drink and eat. We are acutely aware of our energy stores, burning through carbs and dripping out sweat. If it’s not the sweat pouring from our bodies and cueing us to drink up, it’s the parched mouth and the beating sun, urging us to drink ,drink, drink. The truth is, our bodies are well conditioned to deal with heat. We redirect blood flow to the surface of our skin to cool it; we store water differently and have indicators to tell us to drink. The cold is another story.
At altitude we’re breathing more. Actually, we’re breathing a lot. And every breath we take, we’re losing precious moisture out our mouths, from our lungs. This, combined with the dry air, increases evaporation of water from the body. On top of this, when we breathe in the cold air, our body is forced to heat the air and add humidity to it so that our lungs can process it. Often times when exercising, as our breathing rate becomes rapid, our body cannot keep up with the process. This is why a lot of athletes are prone to exercise-induced asthma in the cold. When out on the mountain, you can ease the process of warming the air for your lungs by breathing through a balaclava or neck scarf. If you can carry a warm drink with you while you’re on the mountain, even better. Skratch Hot Apples & Cinnamon drink mix is a great solution.
High altitude also increases the frequency that we urinate at night so sleep with a water bottle beside your bed. Drop a low-calorie hydration mix, like Camelbak Elixir tablets, in it, and replace liquids throughout the night. It’s easier to ingest liquids when you’re not on the mountain, so take advantage of this precious time. When it’s cold, our bodies don’t cue us to drink like they do when it’s hot. However, studies have shown that we do indeed get dehydrated when it’s cold despite our core body temperature not rising. The combination of losing moisture through rapid breathing, the dry air, high altitude, and burning up of carbs dehydrates you and increases the need to fuel. The higher you go, the more you need to drink, and the more carbs you’ll need to eat.
Give yourself time.
When you get to higher altitudes, your body will be working harder than ever before. You also won’t recover as well. If you’re out for a long trip, pace yourself. Reduce the intensity of your days on the mountain and you’ll be able to go at it longer. It’s always better to be conservative for the first week, so you can get to the next. Otherwise, you risk burn out. Make sure you are nourishing yourself properly when the day is done. Let your muscles recover. Hydrate (Don’t skip straight to the apres ski). You will get more out of your days if you’re mindful of what you do with your downtime.
Be careful on the lift.
The real problems start when we stop exercising in the cold. Exercise is great because it produces body heat that our bodies cannot produce on its own. But when we stop, the combination of sweat, movement, and intense breathing can make us even colder. The excess moisture that was keeping us warm becomes detrimental. This is why those moments on a lift, after a hard run can be grueling. The change from warm to cold leaves us quivering and shivering. To avoid this, if it’s possible, try moving just enough to stay warm. Another problem is that the heat and moisture we created when we exercised is not being absorbed by our bodies. Instead, it is getting lost in the atmosphere. The sweat and moisture doesn’t bead up on our brow, it freezes and leaves us. This can lead to dehydration without us being aware of it.
Most importantly, use your head. If it’s too cold to breathe, head indoors, get a hot chocolate and enjoy the marshmallows. Remember, at altitude, your body is working overtime even when you doing nothing.