Ski Mountaineering (Skimo) Nutrition

Last Updated: February 10, 2024

I’ve been skiing since I was 8 years old and backcountry skiing for nearly seven years. I have extensive experience fueling alpine and backcountry skiing. However, it was only this year that I discovered the joy and beauty of skimo (short for “ski mountaineering” and often used in the context of racing), and began to tinker with my nutrition as a result! 

As a sports nutritionist, I couldn’t resist diving into nutrition for ski mountaineering! In this blog, I will discuss nutritional considerations for “skimo” ski mountaineering, including the physiological systems used during this activity and how to tailor your nutrition to support those systems. 

The Differences Between Classic Ski Mountaineering, Backcountry Skiing, and Skimo

There are many different skiing disciplines, so I thought it would be helpful to start by differentiating skimo from other forms of skiing. Let’s dive in!

  • “Classic” Ski Mountaineering: Ski mountaineering uses skis to ascend mountain peaks. It can involve moving with ropes, crampons on your ski boots, and ice axes. It may also include rappelling to get down. The nutrition principles in my blog on nutrition for mountaineering are most applicable to ski mountaineering. 
  • Backcountry skiing: Backcountry skiing is done out of bounds (out of controlled areas) where you are responsible for safely navigating avalanche terrain and setting your own trail through route planning. 
  • “Skimo” Ski Mountaineering: “Skimo” is short for “ski mountaineering” and is usually used to describe skimo racing, the practice of using lightweight skis to alternately climb and descend mountain slopes. Skimo is a rapidly growing winter sport, and skimo racing includes various racing formats that differ in length and vertical gain. (Source

I am discussing nutrition for “skimo” style ski mountaineering in this article. I will use the terms skimo and ski mountaineering interchangeably in this article. 

Use Nutrition with Training to Build a High Aerobic Capacity for Skimo

Having a high aerobic capacity is crucial to your success in skimo. This is demonstrated by positive correlations between skimo race times and maximal oxygen uptake (aka VO2 max, the maximum rate of oxygen consumption that can be attained during physical activity) and oxygen uptake at the second ventilatory threshold (also referred to as the anaerobic threshold). 

While proper training is essential to building a high aerobic capacity, so is your diet. In fact, to create a high aerobic capacity for skimo, dialing in your daily nutrition is just as crucial as your ski day/race day nutrition.

Your body’s aerobic energy system can metabolize fat and glucose for fuel. Improving your body’s ability to burn fat for fuel at varying levels of aerobic exercise effort can help you sustain a longer duration and higher intensity of activity without building up excess lactate (lactic acid), a metabolic byproduct that contributes to the feeling of “burning” muscles and even to bonking during exercise. 

You can improve your body’s ability to burn fat for fuel by eating a healthy balance of protein, carbohydrates, and fat in your diet – carb intake should be neither too low nor too high. I commonly see as a sports nutritionist that many athletes’ carbohydrate intakes are quite high and imbalanced with their protein and fat intakes, which can create an excessive reliance on carbohydrates for fuel and more difficulty burning fat for fuel, leading to burnout during demanding aerobic activities like skimo. 

Optimize Body Composition

Your body performs significant mechanical work fighting against gravity when ski mountaineering during uphill climbs, which are often quite steep. The combined weight of you and your equipment will play a role in how quickly you can move uphill (this is why lightweight gear is so prized in skimo). However, your body weight also plays a role, so optimizing your body composition may help you move faster. (Source

By optimizing your body composition, I don’t mean starving yourself to achieve the lightest weight possible. Instead, we want to focus on building functional muscle mass and maintaining that muscle mass while reducing excess body fat and nourishing our bodies properly with nutritious, wholesome food. 

In my work with my nutrition clients, I help them optimize their body composition through several steps:

  • Identifying their current body weight and composition and determining whether there is room to further optimize their body composition while maintaining optimal health.
  • Assessing their current diet to identify how many calories and how much carbohydrates, protein, and fat they are consuming. 
  • Dialing in their macronutrient intakes to promote the maintenance of lean body mass (which includes muscle) and strength while reducing body fat in a sustainable, healthy way. 

Ideas for Skimo Ski Day/Race Day Fuel

Without proper fueling, a significant calorie deficit may occur in ski mountaineers due to the high energy demands of the sport. Here’s my suggested strategy for fueling during skimo days (where you’re casually participating in skimo and enjoying yourself) and a separate set of suggestions for fueling during skimo races:

Skimo Casual Day

  • 1-3 hours before skiing, eat a meal with a 1:1 or 2:1 ratio of carbs to protein.
  • If skiing for over 90 minutes, consume approximately 30-60 grams of carbohydrates and 3-8 ounces of water every 15 minutes.
  • After skiing, eat a meal that provides a 1:1 or 2:1 ratio of carbs to protein, and drink 16-24 ounces of water for every lb. of body weight lost (due to water losses) during exercise. Add 300-500 mg of sodium as an electrolyte supplement. 

Skimo High-Intensity Training or Race Day

  • The day before your high-intensity skimo training day or race, increase your carbohydrate intake relative to your typical carb intake. You can use the “High-Intensity Day Plate” image below to visualize how much carbohydrate to include at lunch and dinner the day before a high-intensity skimo training day or race. 
  • 1-3 hours before skiing, eat a meal with a 1:1 to 2:1 ratio of carbs to protein with minimal fiber (to avoid upsetting your gastrointestinal system). 
  • Hydrate to thirst before training or racing.
  • Consume 30-90 grams of carbohydrates per hour.
  • Consume 3-8 ounces of water every 15 minutes.
  • Consume 500-700 mg of sodium through an electrolyte supplement for every Liter of fluid consumed during your training session or race. 
  • Afterward, consume 16-24 ounces of fluid for every lb. of body weight lost (due to water losses) during exercise. Consume a meal that provides a 2:1 ratio of carbs to protein. 

Here are some examples of skimo-friendly foods that I suggest for fueling during your activity:

As always, for your nutrition foundation, I recommend eating whole, minimally processed foods, including high-quality meat, poultry, seafood, and eggs (all crucial, bioavailable protein sources), vegetables, fruits, whole-food starches like potatoes, sweet potatoes, root veggies, fruits, and whole grains (if tolerated), full-fat dairy products (if tolerated), nuts, and seeds. 

While you may be able to “get away” with eating highly processed junk foods occasionally, I don’t recommend making these foods a staple in your diet due to their adverse effects on blood sugar balance and inflammation levels inside the body. 

Maintaining Fluid Balance in the Cold

High altitude (such as that experienced during ski mountaineering) can cause dehydration because the lower humidity and increased breathing rate your body experiences at altitude causes your body to lose fluid more quickly than at lower altitudes. 

Furthermore, your kidneys sense the low oxygen levels at altitude and release more erythropoietin (EPO) from the peritubular cells to stimulate red blood cell production. The kidneys also prompt you to pee more to decrease your blood plasma volume and make your hemoglobin more concentrated; hemoglobin is the primary carrier of oxygen in your body. 

In addition, the physical exertion of mountaineering also causes water loss through respiration. 

Finally, cold temperatures (typical in ski mountaineering!) can cause cold diuresis, a phenomenon that your body initiates when it senses cold environments and increases blood flow to your body’s core. 

Altogether, skimo creates a prime environment for dehydration if you aren’t careful!

Dehydration resulting in losing 2-3% of body mass may impair endurance performance, such as ski mountaineering. Dehydration can increase your perceived exertion, making slopes that you previously sped up feel like long slogs. (Source

Here are some guidelines for estimating your fluid needs during mountaineering:

  • Start with your baseline hydration needs. Aim to drink half your body weight in ounces of water daily.
  • According to the Institute for Altitude Medicine, you should consume an additional 1-1.5 liters daily at altitude.

It is also important to consume electrolytes when mountaineering, provided you don’t suffer from a health condition or take medications that preclude using supplemental electrolytes. I often recommend using a low-osmolality electrolyte beverage like Skratch Labs Sport Hydration Mix

Me enjoying a fun morning of skimo!

Final Thoughts (For Now!) on Ski Mountaineering Nutrition

Skimo is an exciting, growing sport with extreme physiological demands and exposure to challenging mountainous environments. The right nutrition plan can help you make the most of your skimo training and race your best! 

The content provided on this nutrition blog is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this blog.

The information and recommendations presented here are based on general nutrition principles and may not be suitable for everyone. Individual dietary needs and health concerns vary, and what works for one person may not be appropriate for another.

I make every effort to provide accurate and up-to-date information, but the field of nutrition is constantly evolving, and new research may impact dietary recommendations. Therefore, I cannot guarantee the accuracy or completeness of the information presented on this blog.

If you have specific dietary or health concerns, please consult a qualified nutritionist or another healthcare professional for personalized guidance.

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Lindsay Christensen Dietitian Nutritionist Colorado

Hi, I'm Lindsay

I help mountain athletes improve their performance through a holistic and inclusive approach to nutrition.

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