Skiing in the backcountry has exploded in popularity in recent years. Comprised of “earning our turns”, alpine ski touring requires “skinning” (efficient hiking) many vertical feet to ski versus the convenience of a ski lift. As such, staying on top of the energy demands is absolutely critical for both mountain stoke and mountain safety. Getting hangry in the backcountry is a one-way ticket to poor turns and poor judgment.
The more intense version of backcountry skiing, known as ski mountaineering (AKA “skimo”) has also grown in popularity as an endurance activity both competitively and recreationally. This usually involves big days in the mountains chasing sweet lines or vertical meters or even dedicated training and racing goals. I’ll also touch on the more specific considerations for this niche of skiing.
So now that the snow is falling here in the West, it’s time to dust off the skis, get our avalanche beacons fired up, and get amped for some powder turns. In addition to getting our gear dialed, it’s just as important to start thinking about fueling those epic days in the mountains so we can feel awesome and focus on being efficient and alert while making our friends jealous on the skintrack.
Podcast version of this article:
Step 1: understanding the nutrition demands of backcountry skiing
Backcountry skiing/alpine touring (AT) is a unique sport in the sense that it can be an all day affair with a mix of long, slow uphill or flat “skinning” to reach the slope we want to ski, followed by a short and sometimes intense effort on the descent that requires a significant amount of strength. Depending on your objectives and experience, backcountry ski tours can range anywhere from a couple of hours to borderline ultra-endurance feats. Many athletes (myself included) are drawn to this because of its special combo of aerobic endurance, leg strength, and a healthy dose of super fun adrenaline and connection with the serenity of a snowy mountain landscape. It’s a hard but beautiful sport, with many hours of walking uphill for a few minutes of downhill.
While most of the effort is relatively low in intensity, the body still uses a lot of energy to power this movement, including carrying our skis and packs up and down the hill. For new skiers especially, it’s easy to push into a higher work rate, demanding more energy from carbohydrate stored in our muscles as glycogen, which becomes depleted much quicker than our fat stores. So while we’re primarly using stored fat to generate the energy needed during those long, slow skins, carbohydrate metabolism is still happening in the background, and anytime the effort gets bumped up and our breathing gets harder we’re tapping into those precious muscle glycogen stores. Snacking on carbohydrate foods will help spare their depletion.
Additionally, exercising in the cold demands even more energy use due to our body having to produce extra heat, with a preference for using carbohydrates stored in our muscles to keep us moving under the stress of cold, activated by our sympathetic nervous system. Plus, where there’s skiing there’s often high altitude, also potentially increasing energy needs. Thus, venturing into the mountains in the winter means we must fuel properly to avoid that oh so bummerful hypoglycemic “bonk” and running our glycogen tank too low which can impair our mental processes since our central nervous system relies heavily on glucose. Becoming hypoglycemic messes with our decision-making skills, which is no bueno in potentially risky situations like backcountry skiing. Since we’re in a cold environment, hypothermia is also a risk and becomes exacerbated by hypoglycemia, which can cause a whole host of other issues.
And for the athletes who are working extra hard training for a ski mountaineering objective or skimo race, energy requirements are even higher. These athletes, like many endurance athletes, are stacking on a significant training load from a volume and intensity perspective. This requires a pretty significant energy intake from a caloric perspective, and in my experience working with a number of these athletes it’s a challenge to meet the requirements consistently.
So, the moral of the story: prioritizing fuel as part of your backcountry tour planning is essential for not only performance and enjoyment, but also safety. Next we’ll cover what that looks like.
Step 2: make a plan
One of the essential habits any avalanche safety course will espouse is the importance of making and sticking to a plan when heading out into the backcountry. Knowing and interpreting the avalanche report and weather, making a route plan with your partners, and having the right safety equipment (and the knowledge of how to use it) and the appropriate gear is critical for having a positive and safe experience.
The same goes for nutrition, but as is the case with so many athletes, often very little to no thought is put into this aspect of planning. Failing to plan is planning to fail as they say…
I like to go through a series of questions, similar to the gear, weather and clothing demands:
How long will I be out there?
Duration and intensity of exercise are the two main factors for determining food requirements during exercise. There is a big difference in what and how much to eat if you’re out for 2 hours vs. 8. This comes with experience and understanding your route, but err on the side of overestimating how long you’ll be out and plan accordingly. For endurance activities like skiing, a good general guideline is taking in roughly 150-240 calories per hour if you’ll be moving for over 90 minutes, so you can work backward and give yourself an estimate of how much you might need. In the next section, I’ll give practical examples.
How intense will it be?
Am I going for a hard effort or a big objective? Or is it a chill Sunday cruise with friends? The higher the effort level, the more food you’ll need, and the more emphasis on carbohydrate-rich foods to keep energy levels high while skinning. This may also change hydration needs, as the harder we work, the more we sweat, and we may want to bring some electrolytes with us.
How much room do I have?
Something worth mentioning is space and weight. It’s a balancing act to pack light enough to not get over-encumbered and have to carry a bunch of extra weight up sometimes thousands of vertical feet, but also have everything you need for a day out. Warm layers, avalanche equipment, water, and food add up quickly. Sometimes we have to sacrifice something to fit the essentials, and if the goal is ultra-light travel, there are ways to maximize calories per space taken up. Learning how to do this is part art and part science. More on this in a bit.
What time am I leaving?
Part of the plan should be what you’re eating for breakfast in the morning and getting on top of it instead of scrambling to find your ski boots and gear while your friends are waiting for you outside. Especially for those early morning dawn patrol missions, it’s critical to have something to eat so you don’t get behind. Our blood sugar drops during the night, so having even a small meal, like a piece of toast with peanut butter and jam or some granola with a banana can give you that little boost to start the day with a topped-up tank and help spare the precious carb stores in our muscles we’ll want to save for the final push to the summit. I’m a big fan of packing overnight oats in a tupperware container for those early morning drives into the mountains, especially in preparation for the big days out when you might need the extra fuel and have some time to digest.
Step 3: organize your food kit
Once you have a grasp on what the day’s plan is going to look like, I recommend putting together a little “kit” of your snacks for easy access in your pack. It doesn’t have to be super complicated or take a lot of time. If it’s a long day: more food, shorter: less, etc. I like using a big ziploc freezer bag or stuffsack and having snacks accessible on the side pockets of my pack. It doesn’t ultimately matter how many snacks you have if they aren’t going to get eaten because they’re buried in the bottom of your pack.
The classic adventure breakfast: oatmeal + coffee. A true match made in heaven.
A good starting point is choosing foods that are familiar, easy to eat and digest when it’s cold and wearing gloves, and take up minimal space. A crumbly homemade muffin might be super delicious, but likely to fall more onto the snow than into your stomach. Same with bananas; I’ve had too many explode in my pack to consider them worth bringing.
Another good rule of thumb to start off with when packing is to think about bringing 1-2 “servings”, ie one to two of these items, for each hour you anticipate being out there, and snacking early and often.
Here are some of my favorite snacks:
dried mango
PB&J sandwich or tortilla wrap (a tried and trued classic)
PRO bar meal bars (dense in calories and nutrition in a pretty small bar)
hummus and avocado wrap
leftover pancakes (pro tip: pair with nut butter packet for a total gamechanger snack)
homemade date, oat, and peanut butter-based energy bars or cookies
Justin’s nut butter packets
coconut date rolls
local pastries (not crumbly though)
Larabars or other simple/real food bar
nuts/trail mix
emergency stash of gels/blocks/Swedish Fish
Favorite pre-tour breakfasts:
overnight oats or warm oatmeal (if there’s time to make)
muesli or granola with yogurt
tofu or egg and potato scramble burrito
toast with PB and sliced banana, maple syrup drizzle
If scrambling for time, some kind of bar like a Larabar or PRO bar
coffee. Lots of coffee.
Of course, these are just a few options that I enjoy, so experiment and find what works for you! I usually try to mix it up with sweet with savory for the long days to prevent palate fatigue, and also bring some treats (like a cinnamon roll) or proper lunch item for the obligatory lunch break at the summit of a peak. Gotta keep morale high. It’s also super PRO to have an extra sandwich or food stash waiting for you in the car for the drive home.
Summit snack time = the best time
You’ll also notice that these are generally pretty “real food” based and also balanced in their macronutrient breakdown. Quick burning “sport foods” like processed gels/blocks/bars etc. are great for activities that are really intense and a lot of strain is put on the digestive system when absolute energy needs are high. But for long, relatively slow days in the mountains, real food is where it’s at. Choose these quick-digesting, simple carb-based snacks for the more fast-paced, skimo-type sessions.
Get those glutes some calories!
Carbs are a key fuel source anytime we’re exercising, but we can and should also call upon using fat as fuel when we’re moving pretty slow and at a low intensity. Fat provides more than double the calories per gram as carbohydrates, which makes it ideal when trying to maximize space in our packs or going for a very lightweight setup. Things like nut butter packets are a fantastic and minimal way to get fuel in the tank. A word of caution though: if you’re not used to eating high-fat foods while moving, it’s a good idea to start small and experiment as it takes longer to digest these foods than it does carbohydrate-rich ones.
For longer, all-day tours, consider bringing a substantial & balanced lunch. I like a nice savory burrito, such as tofu, avocado, spinach, and Bitchin’ Sauce wrap. Ski partner approved.
Step 4: Hydration
Last but far from least: the other major nutrition consideration while out in the backcountry is hydration. It’s actually easier than we think to become dehydrated in the winter for a number of reasons:
1) It’s cold, which can lessen our thirst and drive to drink.
2) the air is drier than in temperate months.
3) we’re often at higher elevations than normal, increasing our fluid needs.
4) we’re working (and breathing) hard on the uphill, getting cold to transition, and then warm again going down. These big swings in temperature mean our body is working harder to keep our core temperature regulated, resulting in heat and sweat loss. Unless you’re a layering god or goddess, it can be tough to perfectly regulate temperature out there.
5) when we’re exposed to the cold, our blood vessels constrict to protect our core temperature, increasing blood pressure and causing the kidneys to push more urine into our bladder and making us pee more often, known as “cold diuresis”. This contributes to more water loss than normal and is important to keep in mind.
6) particularly in the spring skiing season, where large temperature swings are the norm, it’s easy to sweat A LOT when out in the mountains. It’s likely still dry and high altitude, so fluid needs are going to be high as well. If you’re a heavy sweater, it’s probably a good idea to have some electrolytes with you.
So, it’s important to prioritize our hydration in addition to eating, and recognizing that even though we may not feel that thirsty, we’re losing lots of fluid and electrolytes through our sweat and our breathing. Becoming dehydrated in the backcountry becomes a safety risk, with decision-making and concentration becoming impaired. Like with food, sipping early and often is the key to success.
I recommend bringing 2 bottles, one with water/electrolyte drink and one insulated bottle with a warm drink to keep the core temperature nice and toasty.
Here’s a super simple DIY warm sports drink for winter activity:
Jackson’s touring tea:
your favorite type of tea (I like earl grey or chai)
pinch of salt
1-2 TBSP sugar
Insulated water bottle like a small hydroflask
optional: splash of your favorite non-dairy milk
Boil some water and add 1-2 teabags to your bottle. If it’s a plastic bottle, be careful not to make the water too hot! Add the water and the salt/sugar and let steep for a few minutes before taking the bag(s) out. Sip on throughout your tour and enjoy the warm fuzzies while your friends try to drink their frozen plain water out of their camelbaks.
This not only provides fluid, but also helps retain that fluid and maintain electrolyte balance lost from sweat, while providing a little hit of simple sugar to keep blood sugar levels balanced. Plus, it’s a tasty change of pace and helps keep our core temperature warm!
Special considerations for skimo training & racing
This winter, I’m going full nerd mode and focusing on skimo training. I signed up for The Grand Traverse - a 40 mile point to point ski mountaineering race from Crested Butte to Aspen, Colorado. With this endurance sport that is basically competitive backcountry skiing comprising of fast uphill and downhill skiing over short and long distances with an emphasis on fast transitions and lightweight gear, the energy demands are extremely high. Similar to cross-country skiing, skimo is a full body experience. Combine this with big training volumes and competing at high altitudes in the winter months and a lot of the principles outlined above apply - just on a much higher level.
Staying hydrated and fueled while out stacking vertical at the local resort is important, but maintaining optimal energy availability is the biggest difference between recreational backcountry skiing on the weekends and someone training daily for skimo. Skimo is a sport requiring really high endurance capacity and speed at aerobic threshold, but also requires a certain level on body mass with how much uphill travel is involved. This can often lead to athletes (like in cycling and other endurance sports) to place too much emphasis on leanness and body weight at the expense of recovery and optimal fueling. A recent study analyzed the diets of 40 skimo racers competing in a large race in Switzerland, finding they only achieved around 83% of their recommended energy intake, and weren’t meeting their carbohydrate needs. I’ve seen similar outcomes in some of the ski mountaineers I’ve worked with - whether intentionally or unintentionally - energy intake isn’t sufficient to meet the demands of their training.
Diving into the specifics of energy availability is beyond the scope of this article (listen to this podcast to learn more), but the key thing to keep in mind if you’re an athlete wanting to train or compete in skimo: your performance is much more dependent on handling the training load than being at your lightest possible weight. And handling a ton of training requires fueling for the work required, AKA having enough energy onboard over the course of the day, the week, and the year to support normal physiological functioning and training (which is more than we think!). Too many athletes jump into training a lot and intensely without making a nutrition plan, which often leads to low energy availability and compromised performance or worse.
Race Nutrition
Similar to any other fast-paced endurance competition, fueling during becomes a critical factor for performance any time the effort is above ~90 minutes. Most skimo races in the “individual” discipline or teams races, last anywhere from 2-8+ hours! So add up everything we’ve just talked about with regards to mountain safety, hydration, carbohydrate metabolism, etc. and level it up to meet an even higher demand at high intensity race situations and you have skimo racing.
The same general race nutrition principles apply: aim to consume primarily simple, easy to carry, eat, and digest carbohydrates, around 60-90g/hr, in the form of energy gels, sports drink, or chews/blocks/bars. Mastering this is going to be a challenge for any skimo athlete with how faced paced, intense, and technical the sport is with very limited opportunity to eat. This is something you must practice during training sessions and go into the specific race with a fueling plan and understanding of where on the course there might be a chance to squeeze down a gel or take a few gulps of sports drink.
I recommend consulting with a qualified performance nutritionist or sports dietitian to get ahead of both energy availability and race nutrition planning if you’re serious about competing or performing at a high level.
Parting thoughts
I think it’s important to zoom out and remember that the whole point of getting out into the mountains is to have a fun experience, find some flow, and connect with the natural world through meaningful movement. We want to feel great all day, not on the verge of bonking and dragging on that “one more” run on that epic powder day because we forgot to eat breakfast or bring snacks. We want our minds and muscles fueled and sharp in high-risk situations. Fueling matters. It’s a tool for creating those rich experiences, just like our fancy lightweight skis and boots (but much cheaper).
I also think it makes sense to prioritize keeping our brain highly fueled (the brain runs on glucose, AKA carbohydrate) while in potentially risky situations, such as venturing into avalanche terrain. If our brain and muscles are running low on fuel, it becomes harder to a) make good decisions and b) be ready for action if something happens.
So whether you’re going out for a before-work tour or a weekend yurt trip, get your snacks ready and some sport tea in the thermos, it’s go time. For the audio podcast version of this article, check out my episode on Apple Podcasts or Spotify (or wherever you listen to podcasts)!