Ski Touring Nutrition: High-Calorie Food That Won't Freeze

Ski touring and ski mountaineering burn enormous calories in conditions that make eating difficult. Most energy bars freeze solid below 0°C. This guide covers how to stay fuelled when the cold is working against you.

In this guide

• Why ski touring is nutritionally demanding
• The cold problem: why most trail food fails
• Calorie density and pack weight on a ski tour
• What makes food work in sub-zero conditions
• How Phoenix Bars can be used
• Fuelling strategies by tour type
• Frequently asked questions

About this guide

This guide explains the specific nutrition challenges of ski touring and ski mountaineering, where cold temperatures, high calorie burn, altitude, and limited pack space combine to make eating one of the hardest parts of the day.

For broader guidance on high-altitude nutrition, see the High Altitude Mountaineering Nutrition guide. For general ultra-endurance nutrition principles, see the Ultra-Endurance and Expedition Nutrition Guide.

Phoenix Bars are high calorie bars designed for situations where maximum calories in minimum weight is critical. Customers have eaten them at -45°C on a South Pole expedition.

Last reviewed: 2026

Ski touring is one of the most calorically demanding mountain activities. The combination of sustained uphill skinning, altitude, cold, and heavy equipment means a full day of ski touring burns 4,000 to 7,000 calories depending on terrain, elevation gain, conditions, and pack weight. On multi-day tours or hut-to-hut traverses, this demand repeats day after day.

Every experienced ski tourer knows they need to eat. The trouble is that the conditions work against it. Your food freezes in your pack. Stopping to eat means cooling down rapidly in wind and cold. Altitude suppresses appetite. Gloved hands cannot open wrappers. The bar you packed this morning is now a solid brick that could chip a tooth.

The pattern is predictable: strong start, good pace through the morning, then a steady decline in power and warmth through the afternoon as the calorie deficit accumulates. On a day tour, this means a miserable final descent. On a multi-day tour, it compounds until performance and safety suffer.

This guide is for anyone who ski tours long enough and hard enough that nutrition becomes a limiting factor: day tourers, multi-day hut-to-hut ski tourers, ski mountaineers, spring haute route participants, and anyone who has eaten a frozen energy bar with their goggles fogged and their patience gone.

Why Ski Touring Is Nutritionally Demanding

Ski touring combines several factors that individually increase calorie needs and together create a significant fuelling challenge.

High energy expenditure. Skinning uphill with a loaded pack at altitude burns 600 to 900 calories per hour depending on gradient, snow conditions, pack weight, and body weight. A six-hour touring day with 1,200m to 1,800m of ascent burns 4,000 to 5,500 calories from the touring alone, on top of a baseline metabolic requirement that is itself elevated by cold and altitude.

Cold increases calorie burn. The body burns additional energy to maintain core temperature in cold conditions. This thermogenic effect adds 10 to 20% to calorie expenditure depending on temperature, wind, and how well insulated you are. In severe cold, the increase can be higher. This means calorie needs are elevated even during rest stops and at the hut.

Altitude suppresses appetite. Above 2,000m, appetite typically begins to decline. Above 3,000m, the effect is pronounced. Many ski tourers report being unable to face food at altitude despite knowing they need it. The body needs more calories at altitude (due to increased breathing rate and metabolic demand) at the same time that the desire to eat is reduced.

Stopping to eat means getting cold. On a skin track in wind, every minute you stop is a minute you are cooling down. Eating requires removing gloves, opening wrappers, and standing still. In windy or exposed conditions, this creates a strong disincentive to eat, and many tourers skip food stops to avoid the chill. The deficit then builds unnoticed until performance drops.

Sweating under layers creates hidden fluid and calorie loss. Skinning is hard physical work. Even in cold conditions, tourers sweat heavily under multiple layers. This fluid loss reduces appetite and can mask the early signs of calorie depletion. By the time you feel hungry, you are already significantly behind on intake.

The Cold Problem: Why Most Trail Food Fails

Frozen food is the problem that catches most tourers out, and the reason standard trail food so often fails on a ski tour.

Below 0°C, most standard energy bars become rock-hard. The binding agents in typical bars (honey, syrup, chocolate) solidify in cold. A bar that is soft and chewy at room temperature becomes a solid block that cannot be bitten into, let alone chewed, at -5°C or below. Many tourers have tried to eat frozen bars and either given up or risked dental damage.

Energy gels have a different problem: the packets become nearly impossible to open with cold or gloved hands, and the gel itself thickens in cold temperatures, making it slow to consume. Some gels freeze entirely.

Chocolate freezes solid. Cheese becomes hard. Nuts are fine but deliver limited carbohydrates. Sandwiches freeze and become unpleasant to eat.

The workaround most tourers use is to store food inside their jacket, close to their body, to keep it warm. This works for small items but is impractical for carrying a full day's food supply. It also means food is only accessible when you stop, remove layers, and dig around in your clothing, which adds time and cold exposure.

The ideal solution is food that simply does not freeze. Food that remains soft, chewable, and edible at any temperature you are likely to encounter on a ski tour removes the problem entirely.

Customers report that Phoenix Bars stay easy to eat in serious cold. Shaun Weston took them on a South Pole expedition:

"Flaming Phoenix Bars featured as a star in my food supply for my recent South Pole expedition. Easy to eat, even at -45c."

Calorie Density and Pack Weight on a Ski Tour

Calorie density is how many calories a food delivers per gram. On a ski tour, it determines how much energy your food provides relative to the weight in your pack.

Every gram on your back is a gram you skin uphill. Heavy food means slower skinning, more fatigue, and higher calorie expenditure, which means you need even more food. The cycle is self-defeating.

A standard energy bar delivers 150 to 250 calories in 40 to 60g (our ranking of the best energy bars for expeditions compares them on calories per gram and how they cope with cold). A Phoenix Bar delivers up to 557 calories in only 120g, roughly 4.6 calories per gram. To carry 3,000 calories of on-tour food, you would need twelve to fifteen standard bars (600 to 900g) or six Phoenix Bars (720g, over 3,100 calories).

On a multi-day hut-to-hut tour where you carry food for several days between resupply, the weight saving compounds. Ten Phoenix Bars (1.2kg) provide up to 5,570 calories; the same calories from standard bars at around 3.75 calories per gram (150 calories in 40g) would weigh about 1.5kg.

When you are skinning uphill at altitude with a heavy pack, every gram matters. Higher calorie density means less weight for the same fuel.

What Makes Food Work in Sub-Zero Conditions

The requirements for ski touring food are specific.

Does not freeze. This is the non-negotiable starting point. If you cannot bite into it at -10°C, it is dead weight in your pack. Food that remains soft and chewable across the full range of temperatures encountered on a ski tour is essential.

Edible with gloves on. Removing gloves to eat means cold hands, dropped food, and wasted time. Food that can be eaten while wearing liner gloves or thin ski gloves, or that can be broken into pieces and eaten from a pocket, is far more practical.

High calories per gram. Less weight means faster, easier skinning and less fatigue. Higher calorie density means more calories for less pack weight.

Mixes carbohydrate with fat and protein. Skinning is an aerobic effort lasting hours. Food that combines carbohydrates with fat and protein is absorbed over a longer stretch, which suits a full touring day better than pure sugar.

Not excessively sweet. On a long, cold day, intensely sweet food becomes unappealing. Milder, more neutral flavours sustain appetite across repeated eating events. This is especially important on multi-day tours where you are eating the same food day after day.

Compact and durable. Food needs to survive being packed into a ski touring rucksack alongside skins, crampons, a shovel, and a probe without being crushed. Water-resistant packaging is a bonus in snowy conditions.

How Phoenix Bars Can Be Used

Most energy bars freeze solid below 0°C. Climbers who have used Phoenix Bars on Manaslu and Denali say they don't freeze easily, and the soft texture means you can bite into one without risk to your teeth or your patience. On a ski tour, they can be pre-broken into pieces and stored in a chest pocket for continuous eating without removing gloves, or mixed with hot water from a flask at a hut for a calorie-dense porridge that gives you warmth and calories at once.

On the skin track. Break a bar into pieces before setting off and store them in a chest pocket or hip belt pocket. Eat a piece every 20 to 30 minutes without stopping. This keeps calories flowing in steadily without the need to stop, cool down, remove gloves, and rummage in a pack. A full bar eaten over 90 minutes gives roughly 350 to 370 calories an hour.

At transition points. When you stop to remove skins, put on a jacket, or regroup, eat a half or full bar alongside water. Transitions are natural eating opportunities because you are already stopped. Use them.

At the hut. If the hut has hot water or you are carrying a flask, make a Phoenix Bar porridge for a hot meal of up to 557 calories in two minutes. On a hut-to-hut tour, this can serve as a quick breakfast before an early start, or as a calorie boost on arrival before the evening meal.

In the emergency kit. A single Phoenix Bar provides up to 557 calories of shelf-stable emergency food in only 120g. If conditions deteriorate, a tour takes longer than expected, or someone in the group runs out of energy, it is immediately available with no stove or water needed.

"I have used Phoenix bars on several events including deep arctic cross-country ski-ing in -35 degrees" (Stuart Deel-Smith, September 2026)

Full nutritional information and ingredient lists for all six flavours are available on the product page.

Fuelling Strategies by Tour Type

Day tour (single ascent and descent, 4 to 6 hours). Pack two Phoenix Bars (up to 1,114 calories, 240g) alongside water and whatever else you carry. Break the first bar into pieces before you start and eat them steadily on the ascent. Eat the second at the summit or during the transition. This provides a reliable calorie backbone without needing to stop for a formal food break.

Long day tour (multiple ascents, 6 to 10 hours). Pack three to four bars (about 1,600 to 2,200 calories). Eat portions consistently throughout the day. Supplement with whatever you eat at huts or shelters. Do not wait until you feel hungry. On a long cold day, hunger signals are suppressed by altitude and cold. Eat on a schedule, not on appetite.

Multi-day hut-to-hut tour (3 to 7 days). Pack three to four bars per day for on-tour food. Hut meals provide dinner and often breakfast, but the hours between are your responsibility. Phoenix Bars provide calorie-dense, lightweight trail food for the hours between huts. For a five-day tour, fifteen bars (1.8kg) provide up to 8,355 calories of guaranteed fuel regardless of what huts offer.

Ski mountaineering (technical terrain, long approaches, high altitude). The demands are the highest here: sustained effort at altitude with heavy technical kit. Calorie needs can exceed 6,000 per day. Pack four to five bars per day and eat aggressively. At altitude, appetite will be suppressed. Do not wait for hunger. The porridge format is useful if you have a flask or can access hot water, as warm food is easier to eat at altitude and helps morale.

Spring touring (warm approaches, cold summits). The temperature range in a single day can span 15°C in the valley to -10°C at the summit. Food needs to work across both. Customer reports cover both ends: a Marathon des Sables runner found they kept their shape even in desert temperatures, and skiers have used them in the Arctic at -35°C.

Related Guides

• High Altitude Mountaineering Nutrition
• Ultra-Endurance and Expedition Nutrition Guide
• Hiking and Trekking Nutrition
• Cycling and Bikepacking Nutrition
• UK Ultra Race Nutrition
• How To Use Phoenix Bars
• Calorie-Dense Foods: What They Are and When They Help

Frequently Asked Questions

Do Phoenix Bars really not freeze?

Not easily, by most customers' accounts, though they are not immune to deep cold. Shaun Weston found them easy to eat at -45°C on a South Pole expedition and Alex Welch ate one a day through the -40°C Beyond The Ultimate Ice Ultra, while another Ice Ultra runner found they did freeze. In the hardest cold, keep the next few pieces in a chest pocket.

How many calories do I need per day ski touring?

A full day of ski touring with significant ascent burns 4,000 to 7,000 calories depending on terrain, altitude, conditions, pack weight, and body weight. You will not replace all of this through food alone. The goal is to minimise the deficit enough that performance and safety are maintained. Budget 2,000 to 3,000 calories of on-tour food per day, supplemented by hut meals.

How many Phoenix Bars should I carry per day?

For a standard day tour, two to three bars (about 1,060 to 1,670 calories). For a long day or ski mountaineering objective, three to five bars. For multi-day hut-to-hut tours, three to four bars per day for on-tour food, with hut meals covering breakfast and dinner.

Can I eat Phoenix Bars with ski gloves on?

Yes. Break a bar into pieces before you start, or bite directly into the bar. The soft texture means it does not require the grip strength or dexterity that frozen bars demand. Storing pre-broken pieces in a chest pocket means you can eat without removing gloves at all.

How do Phoenix Bars compare to other ski touring food?

Most standard energy bars freeze below 0°C and become inedible. Chocolate freezes. Gels thicken and packets are hard to open. Nuts are cold-resistant but low in carbohydrates. Phoenix Bars carry up to 557 calories in only 120g, with up to 66g of carbohydrate and 19g of protein, and customers have found them easy to eat from the Arctic to the South Pole. A chest pocket still helps on the coldest days.

Buy Phoenix Bars

If you have any questions about using Phoenix Bars for ski touring or ski mountaineering, contact me directly. I am always happy to help.

James Frost

Founder, Flaming Phoenix

jfrost@flaming-phoenix.co.uk

07990 519422