Cold-Weather Long-Run Fueling: Carb and Sodium Targets That Stick
Running long distances in cold weather requires a different fueling strategy than summer training. Sports nutritionists and endurance coaches recommend consuming 30 to 50 grams of carbohydrates per hour, supplemented with sodium tablets to maintain performance. This article breaks down the science behind winter fueling and provides practical guidance from experts who work with distance runners year-round.
Target 30 to 50 Carbs Then Salt Tabs
My fueling protocol doesn't change much in cold weather, but my hydration strategy does.
For long runs up to two hours, I usually carry a handheld bottle and take small, regular sips throughout the run, mainly to stay topped up and to wash down nutrition. For runs longer than two hours, I'll often plan one or two short stops at a cafe or corner store to grab a drink and warm up briefly before continuing. A hot tea or coffee can make a big difference when spending several hours outside in very cold conditions, and it's an easy way to increase fluid intake when thirst cues are low.
For fueling, I typically aim for 30-50 g of carbohydrates per hour, depending on the duration and intensity of the run. I get this from a mix of gels and solid foods, such as bars or candy. While I don't visibly sweat as much as I do in warm weather, I still prioritize electrolytes and aim to take in sodium about every 30 minutes. In cold conditions, I find salt tabs or chews work best, as they don't require drinking large volumes of water and are easy to stay consistent with when it's cold.
Use Body Weight and Maintain Electrolyte Support
Using body weight keeps intake steady in the cold. A target of 0.7 to 1.0 grams of carbs per kilogram each hour fits most long runs. Pair that with about 600 milligrams of sodium each hour to support fluid balance. Split carbs into small sips or bites every 10 to 15 minutes to avoid stomach upset.
Set a watch alert because cold air can mute thirst and hunger. Practice this plan on long training runs to confirm comfort. Build your weight based fueling plan and test it on your next long run.
Choose 2 to 1 Sugars and Balance Sodium
Mixing sugar types can raise uptake when the gut is stressed by cold. A 2 to 1 ratio of glucose to fructose helps push more carbs across the gut wall. Use a drink mix or gels that list this ratio, and keep sodium between 600 and 1000 milligrams per liter. This range supports fluid pull without making the drink harsh in the cold.
If using gels with water, aim for the same ratio across the hour, not in a single sip. Check labels and note totals so the hour adds up well. Choose a product with the right ratio and trial it during a chilled easy run.
Prime with Fuel and Warm Sports Drink
Starting fueled makes the first hour smoother and warmer. Take in 1 to 2 grams of carbs per kilogram in the two hours before the run. Add 500 to 1000 milligrams of sodium in that window to help hold fluid. Use a simple meal plus a warm sports drink to ease the stomach in cold air.
Keep fluid to thirst so bathroom stops do not cut into the run. Top up with a small carb dose 10 to 15 minutes before heading out. Plan your pre run meal and drink today so it is ready before your next long run.
Concentrate Bottles and Raise Hourly Intake
Hourly targets give a clear lane during long cold runs. Aim for 60 to 90 grams of carbs each hour while keeping sodium between 500 and 1500 milligrams per liter of fluid. In cold weather drink rates often drop, so increase drink strength rather than forcing more volume. A concentrated bottle plus sips of water can hit the right numbers without a sloshy gut.
Keep notes on carb grams and sodium per bottle to line up with your pace and stops. Adjust only one thing at a time to see what helps. Map your bottle plan and rehearse it on your next steady long run.
Increase Energy for Chill and Keep Minerals Steady
Cold raises energy needs through shivering and extra layers, so a modest bump can help. Increase carbs by about 10 to 20 percent over mild weather plans when runs last two hours or more. Keep sodium near 500 to 700 milligrams per hour since sweat loss is lower but not zero. Warmer drinks and soft chews stay pliable and are easier to use with gloves.
Set intake alarms because hunger cues are weaker in the cold. Watch for signs of underfueling like chills and fading pace, and act early. Draft a cold day version of your plan and try it on your next chilly long run.