FUELLING THE MACHINE: NUTRITION FOR BIG DAYS

The Technique

1. Physical conditioning gets all the attention, but preparing your body and fuelling it are two different jobs. Backcountry days combine sustained physical effort, cold stress, altitude in some places, and a constant need for clear decision-making. Running out of fuel does not just make you slow, it makes you make bad calls, and bad calls in the backcountry are how people get hurt.
2. Carbohydrate is what matters most. Muscle stores carbohydrate as glycogen, and glycogen is what you burn during hard, sustained effort. When it runs low, power drops, coordination degrades and concentration goes with it. Cold weather raises the bill further: you are burning energy to stay warm, and you are doing it in heavy gear.
3. Load before a genuinely huge day - a full backcountry day, a multi-day trip, or a big event. Increasing carbohydrate intake in the 24 to 48 hours beforehand tops up glycogen stores. Endurance-sport protocols use figures around 8 to 10 g of carbohydrate per kilogram of body weight per day in that window. That is the upper end, used by trained athletes before long events. Most riders do not need to chase the top of that range. Simply making carbohydrate the clear centre of your meals for a day or two beforehand captures most of the benefit. Favour lower-fibre, easily digested sources: rice, pasta, bread, potatoes, ripe bananas, pretzels, honey, jam, juice, sports drinks. Ease off high-fibre vegetables and heavy fats in the final day if gut comfort is a concern for you.
4. Keep protein moderate and stay well hydrated through the loading window. Stored glycogen carries water with it, so expect a small weight gain. That is the system working. No alcohol the night before, because it costs you sleep quality, hydration and thermoregulation, all of which you need.
5. On the morning of, eat a familiar, carbohydrate-focused meal one to four hours before you start. The size scales with how long you have got to digest it. Nothing new on a big day either: new food, new supplements, new gels all get tried on training days, not on a day you have saved a year for.
6. On the snow, take in carbohydrate steadily through the day, roughly 30 to 60 g per hour of sustained hard riding, more if you are hiking, digging or working at altitude. Practical options that survive a backpack and cold: gels and chews, bars (soft ones, because hard bars freeze solid), dried fruit, pretzels, jerky, sports drink powder. Keep some food in an inside pocket where body heat stops it freezing.
7. Eat before you are empty. Once you have bonked, you cannot eat your way out of it quickly. Set a rough interval and stick to it whether you feel like it or not.
8. Drink to a schedule, not to thirst. Cold blunts the thirst response, and cold-induced diuresis means you lose fluid faster than you notice, so people routinely finish a snow day significantly dehydrated without ever feeling thirsty. Carry warm fluids in a thermos: warm sweet drinks do three jobs at once, fluid, carbohydrate, and heat delivered into the core. On a cold, wet, morale-flattening afternoon, a hot drink is worth more than any of them individually. It is also the fastest tool you have for someone in the group who is starting to get cold and quiet. Insulated bladder hoses freeze, so blow the water back down the hose after every drink, or carry bottles instead.
9. Include a solid protein source after big days to support recovery, especially on multi-day trips where tomorrow matters as much as today. High-protein snacks, jerky, nuts and protein bars are worth carrying, but they are a supplement to your carbohydrate intake during the day, not a substitute for it.
10. Treat nutrition as part of the preparation, not an afterthought. Preconditioning gets you to the trailhead capable. Fuelling is what keeps you capable at 3pm, on the last climb, when the decisions get harder.

Common Mistakes

Chasing the top of the 8 to 10 g per kilogram range because it is the number you read. Fix: that figure is the upper end used by trained athletes, so just make carbohydrate the clear centre of your meals for a day or two and take most of the benefit.

• Trying a new gel, bar or supplement for the first time on the big day. Fix: test everything on training days, not on a day you have saved a year for.
• Waiting until you feel empty before you eat. Fix: set a rough interval and stick to it whether you feel like it or not, because once you have bonked you cannot eat your way out of it quickly.
• Drinking to thirst in the cold. Fix: drink to a schedule instead, and blow the water back down an insulated hose after every drink or carry bottles.
• Living on protein bars and jerky through the day. Fix: they supplement your carbohydrate intake, they do not replace it.

The Drill

Run your fuelling plan on a long training day before you run it on a trip. Same familiar carbohydrate breakfast one to four hours before you start, the same food you intend to carry, packed the way you intend to carry it with some in an inside pocket, a thermos of warm sweet drink, and a set interval you eat and drink to whether or not you feel like it. Write down what you actually ate and drank as you go. Anything that upset your gut, froze solid, or that you could not face by the fourth one gets swapped out before departure.

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