Sledging rations: from pemmican to the modern polar ration

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. Updated November 2026.

Quick answer: A sledging ration is the food a polar party hauls to travel long distances with no resupply. Historic rations gave about 4,200 to 5,500 calories a day from pemmican, biscuits and butter; modern unsupported crossings plan on roughly 5,000 to 8,000 a day at 4.5 to 5 calories per gram, so a day's food weighs about 1 to 1.8kg.

Three things define it: enough calories for huge daily effort in extreme cold, the highest possible calories per gram because every gram is dragged the whole way, and food that stays edible when it is far below freezing. Today that means dehydrated meals, butter and oil, chocolate, nuts and cold-stable high calorie bars, built around a big breakfast, hourly snacks eaten on the move, and a hot dinner in the tent.

This page covers what the sledging-ration terms mean, how the ration developed from pemmican and biscuits to freeze-dried meals, and how the modern version is put together. For the full planning detail on a specific trip, I will point you to the deep guides as we go, starting with the master one on polar expedition nutrition.

What is a sledging ration?

A sledging ration is a ration designed for sledging parties travelling long distances without support vehicles. The whole design problem is that you must carry, or rather haul on a sledge or pulk, every calorie you will eat, so the ration has to be as calorically dense and as light as possible while still keeping you alive and moving in brutal cold. That is why sledging rations are traditionally dehydrated, since water is dead weight you can add later from melted snow.

Three words you will meet straight away. Sledging biscuits are hard, long-life biscuits made from flour, salt, butter, water and a little baking soda, prized because they pack a lot of calories into a durable, non-perishable form. Hoosh is the classic sledging meal, made by crumbling pemmican and sledging biscuit into hot water to make a thick stew. And pemmican, the staple of the early rations, is rendered fat mixed with dried meat, which for a century was the densest travel food anyone had, because fat carries more than twice the calories per gram of carbohydrate or protein.

A short history of the sledging ration

The history is really a history of one repeated mistake: underestimating how much a person burns hauling a sled in the cold. Robert Falcon Scott's fatal South Pole expedition is the cautionary tale. His sledging ration of pemmican, fortified biscuits, butter, sugar, cocoa and tea gave about 4,430 calories a day, and a 2012 analysis by Lewis Halsey and Mike Stroud estimated the polar party was burning nearly 7,000, a shortfall of about 2,500 calories a day that contributed to the exhaustion that killed them. The lesson learned early and painfully in Antarctica was that man-hauling in the cold burns an enormous amount, and that hunger and hypothermia are linked, because your body can only keep you warm if you keep feeding it.

Rations got more scientific from there. In 1930 the explorer Gino Watkins developed a sledging ration for the British Arctic Air Route Expedition built mostly from pemmican, margarine and fortified biscuits, rounded out with pea flour, oats, sugar, cocoa, chocolate and Horlicks, and set at 5,522 calories a day. A modified version stayed one of the most popular rations for polar parties until the 1950s. The British North Greenland Expedition ran on a 4,164-calorie ration of pemmican, butter, potato powder, cocoa, chocolate, sugar, oats, dried milk and biscuits, and by 1959 the optimum for sledging crews had been pinned at around 4,800 calories a day. Modern British Antarctic Survey field rations sit lower, around 3,500 calories a day, because a lot of modern fieldwork is less punishing than a full man-hauling traverse, and they lean on freeze-dried mains plus tea, coffee, chocolate, biscuits, butter, sugar and powdered milk, with a supplementary "goodies box" of herbs, spices and condiments. The through-line across all of it is the same: fat for density, dehydration for weight, and sweet, familiar treats to keep you eating when appetite and mood sink.

The table puts the main rations side by side. Calories are per person per day as published for each ration; the last row is a typical planning range rather than a single ration.

How many calories does a sledging ration provide today?

It depends entirely on what you are doing, and this is where the historical numbers can mislead. A supported science team doing day trips from a base needs far less than a skier hauling a pulk to the Pole. The hard end, an unsupported man-hauling crossing, is a special case, because you cannot carry enough food. When Mike Stroud measured himself and Ranulph Fiennes on their 1992 to 1993 crossing of Antarctica, they burned nearly 7,000 calories a day on average and more than 11,000 a day over one ten-day stretch, while eating about 5,090. Most unsupported crossings are still planned at roughly 5,000 to 8,000 a day, because every extra kilo of food slows every day of the trip. The gap is covered deliberately, by body fat gained before departure, which is why expedition skiers routinely finish 5 to 20 kilograms lighter, and Fiennes and Stroud each lost more than 20kg. The full logic of that trade-off sits in 10,000 calories a day, and the calorie equation for a specific crossing is worked through in Antarctica solo crossing food.

Why does calorie-to-weight ratio matter so much?

Because you haul every gram, calorie density (the calories delivered per gram of food) matters more in sledging-ration planning than taste or nutrition on paper. On a long unsupported crossing, aim for the highest average density you can across the whole food bag, ideally 4 to 5 calories per gram, because every extra gram makes the pulk harder to drag the distance. That is why traditional and modern rations alike are fat-heavy. Fat provides about 9 calories per gram, more than double the roughly 4 of carbohydrate or protein, so butter, oils, cheese, salami and pemmican do the density work, while carbohydrates stay in the bag because your brain and muscles burn them more readily and they need less oxygen to metabolise, a help at altitude on the polar plateau. The full ranking of foods by density is in calorie-dense foods, and it is the reason most fresh or minimally processed food never makes a sledging ration.

How much does a day's sledging ration weigh?

Roughly 1 to 1.8kg per person. Divide the day's calories by the average calories per gram of the food bag: 5,000 calories at 5 per gram is 1kg, 6,000 at 4.5 is about 1.3kg, and 8,000 at 4.5 is about 1.8kg. Scott's 4,430-calorie ration weighed a little over two pounds (about 0.9kg) per man per day, a little under 5 calories per gram, because so much of it was pemmican, butter and biscuit.

Small differences add up over a long trip. On a 50-day crossing at 6,000 calories a day, food averaging 4.5 calories per gram weighs about 67kg; at 5 calories per gram it is 60kg, nearly 7kg less to drag.

What goes in a modern sledging ration?

The modern sledging day has a shape, and the ration is packed to fit it. Breakfast in the tent is a big, warm, calorie-dense sitting, most often a fatted porridge of oats, powdered milk, sugar and added butter or oil, aiming for something like 1,000 to 1,500 calories to lay the day's foundation. The heart of the day is the daytime ration bag, packed per hour, because you eat on the move at brief stops roughly every hour for eight or nine hours, taking in around 450 to 550 calories each time. Dinner is a freeze-dried main in the tent with fat stirred through and a hot drink loaded with milk powder. The full breakdown of this structure, with what to carry and how much, lives in the polar expedition nutrition guide.

The daytime bag is the hard part, and it is worth dwelling on. Those snacks have to be found and opened with huge gloves on, eaten in a few bites without stopping properly, and they must not freeze into something you cannot bite, because in serious cold most bars and flapjacks turn to rock below about -15°C. Nothing in that hourly block should require bare hands, a long stop, or real chewing effort. That is why the daytime bag is usually built around a bar that stays biteable in the cold (my expedition energy bars ranking scores bars on exactly that) and rotates through chocolate, nuts, cheese, salami and dried fruit, both to hit the calories and to hold off the flavour fatigue that sets in over weeks.

Where does a cold-stable bar fit in a sledging ration?

I make Phoenix Bars, so read this section with that in mind. A bar solves the daytime-bag problem and doubles as a breakfast base, which is why customers have taken my bars to the South Pole and into the Arctic. They won't freeze or melt, so they can be broken into pieces and eaten with gloved hands at an hourly stop; one customer found them "Easy to eat, even at -45c" on a South Pole expedition. Each one carries up to 557 calories in a compact, 120g bar, about 4.6 calories per gram, and there are six flavours, which helps when palate fatigue sets in on a multi-week trip. They can be eaten cold on the move, or mixed with water to make porridge in the tent for a quick breakfast. A shelf life of up to two years means you can buy them months ahead and ship them with your duffel. For the different ways to use them, see how to use Phoenix Bars.

Frequently asked questions

What is a sledging ration?
It is the calorie-dense, weight-optimised food a polar party carries to travel long distances hauling its own supplies without resupply, traditionally dehydrated to save weight and built to stay edible in extreme cold.

What is a sledging biscuit?
A hard, long-life biscuit made from flour, salt, butter, water and baking soda, used on polar expeditions because it packs a lot of calories into a small, durable, non-perishable form. Crumbled into hot water with pemmican, it makes the classic stew called hoosh.

What is pemmican, and why was it used?
Pemmican is rendered fat mixed with dried meat. It was the staple of historic sledging rations because fat delivers about 9 calories per gram, more than double carbohydrate or protein, giving explorers the most calories for the least hauled weight.

How many calories are in a sledging ration?
Historic rations ran from about 4,200 to 5,500 calories a day, with modern base-supported field rations nearer 3,500. An unsupported man-hauling crossing is planned at roughly 5,000 to 8,000 a day even though a skier can burn 7,000 or more, with the deficit covered by body fat.

What food works below -40°C?
Fats like butter and oil, dehydrated meals made up on the stove, hard cheese and cured meats sliced in advance, nuts, chocolate (which goes hard and brittle, so break it up the night before) and bars that don't freeze solid. Many standard bars and flapjacks freeze hard enough to be very difficult to bite.

How do modern sledging rations differ from historic ones?
The principles are unchanged, fat for density, dehydration for weight, treats for morale, but pemmican and sledging biscuits have largely given way to freeze-dried mains, modern fats, and manufactured snacks and bars, with better understanding of the true calorie burn.

Related guides

For the full planning detail: polar expedition nutrition is the master guide, Antarctica solo crossing food and Greenland crossing food cover specific traverses, 10,000 calories a day explains the burn-versus-intake trade-off, calorie-dense foods ranks the raw materials by density, and adventure nutrition is the overview above all of them.

Written by James Frost, founder of Flaming Phoenix and the maker of Phoenix Bars. The bars have been used on South Pole and Arctic expeditions and are rated 4.9 out of 5 in customer reviews. This guide reflects that experience alongside the documented history of polar rationing. It is general information, not medical or expedition-safety advice, and serious cold-weather travel should be planned with qualified guidance. Last reviewed: November 2026.

Sources: Halsey and Stroud, 100 years since Scott reached the Pole: a century of learning about the physiological demands of Antarctica, Physiological Reviews, 2012; Stroud and others, European Journal of Applied Physiology, 1997; Wikipedia, Sledging ration (historic ration figures and the references it cites).