Fueling for road or foot marches: In-depth

Just as the proper gear and training are critical for mission success, nutrition is key for completing grueling military events such as road and foot marches. Nutrition can make or break a Warfighter’s ability to complete the march and affect well-being, endurance, and recovery. In addition, extreme environments, heavy clothes or equipment, and environmental terrain require Service Members to adjust their energy and fluid intake for peak performance.

Service Members need to be properly fueled before, during, and after the event, so this means eating and drinking the right mix of nutrients at the right times for optimal mental and physical performance. The following guidelines support Warfighters in developing a proper performance-fueling strategy.

Macronutrients

Carbohydrates are the preferred fuel for the brain and working muscles. Carbohydrate stores are limited, so providing continuous sources of carbs during endurance activities supports the muscles and maintains blood sugar. A nutrition plan with carb-rich meals and snacks before, during, and after a ruck march helps Service Members perform at their best.

Protein supports muscle growth, recovery, and repair, making it an essential part of pre-meal fueling and post-event recovery. However, protein provides very little energy during endurance events such as ruck marches, so encourage Service Members to focus on adequate intake of calories, carbohydrates, and fluid.

Healthy fats are calorie-dense and add nutrients, taste, and a sense of satiety to well-balanced meals. It’s important for Warfighters to include these in meals the evening before the event and during recovery. Also, they should limit fat close to start time and during activity because this slower digesting nutrient can cause gastrointestinal (GI) upset.

Fuel

A successful nutrition plan can include “everyday” foods (crackers, peanut butter and jelly sandwiches) that are easily found at military dining facilities, commissaries, grocery stores, and even mini-market or convenience stores. Specialized products, such as “sports foods” (gels, “goos,” bars, blocks) can also be used with or in place of traditional foods. These foods are often formulated for a phase of activity (“pre,” “during,” or “post”), provide nutrient breakdown on the labels, and are packaged to be portable and shelf-stable. However, they’re more expensive. So, it’s essential for Service Members to choose a combination of fuel and fluid that meets their individual needs, preference, taste, and budget. Most importantly, the best fuel is one that’s available, appealing, and tasty. Notably, endurance exercise in extreme conditions (heat, cold, altitude) might negatively affect appetite and desire to drink fluids. This makes it even more important for Service Members to have a variety of fuel and fluid they enjoy.

Service Members should eat tried-and-true foods before and during the march. Test fueling options (food, sports drinks, or “sports food” such as gels or bars) as part of training. Ask Warfighters to avoid experimenting with new foods or drinks the day of an event, such as a road or foot march, to avoid intolerance and GI upset.

Fluid

Dehydration of just 2% loss of body weight can negatively affect performance. Service Members should aim to begin a road or foot march well hydrated and continue drinking throughout the event to stay hydrated. Keep in mind that thirst is a poor indicator of hydration, and Service Members might need to be encouraged to drink and take in electrolytes (through food or fluid) even when they’re not thirsty.

Hydration needs also vary among individuals and are affected by environmental factors (heat, cold, altitude), clothing, gear, intensity, sweat rate, etc. Service Members might be more apt to drink sweetened or flavored beverages, so sports drinks are a good choice to provide fuel (carbs + electrolytes) and fluid, especially in heat and humidity. Encourage Service Members to sip rather than gulp fluids.

For ease, use 16 fl oz for fluid guidelines. This is easily translatable into standard water containers: for example, 16 fl oz water bottle, ½ 1-quart canteen, 100-oz hydration pack (finish in 4–5 hours).

Electrolytes

Electrolytes—such as sodium, potassium, and magnesium—are lost through sweat with exact amounts dependent on sweat rate, intensity and duration of activity, environment, equipment, or clothing. Full rehydration can’t occur without adequately replenishing electrolytes. Drinking beverages that contain electrolytes such as sports drinks and eating foods that naturally contain electrolytes (potassium from dried fruit, etc.) aid in replenishing losses. Service Members shouldn’t restrict sodium intake during or after endurance activities such as foot or road marches.

Caffeine

Warfighters should avoid caffeine 4–6 hours before bed to limit interference with sleep, especially prior to a ruck march. In addition, caffeine can boost performance when taken 30–60 minutes before an event. Service Members should aim for 200 mg caffeine: the amount found in a 16-oz coffee, two pieces of caffeinated gum or mints, or one energy drink (caffeine content varies by brand and size, so check amount on label if available). Focus on “cleaner” sources of caffeine such as coffee and tea over energy drinks, which might contain other dietary supplement ingredients, sugar, artificial flavors, colors, etc.

Warfighters who are sensitive to caffeine, have certain medical conditions, or are on specific medications should use caffeine with caution. In general, they should limit caffeine to 600 mg over 24 hours and no more than 800 mg for sustained operations. Visit the Operation Supplement Safety website at OPSS.org for more information on caffeine for performance.

Ruck march fueling

Time: Night before event

Purpose: Fueling up on a carb-rich meal helps to maximize glycogen stores. 

Fuel: Warfighters should choose whole-grain carbs (whole-grain bread, brown rice, quinoa, whole-wheat pasta) for nutrient-rich options. They can balance out the meal by including lean protein (lean beef/pork/chicken/turkey, seafood/fish, tofu) and healthy fats (olive oil, avocado, nuts). Follow HPRC’s “Power Plate – Eat to Fuel Your Performance” for guidance on building a balanced, nutrient-dense meal.

Fluid: Suggest Service Members drink healthy fluids such as water, milk, or milk alternatives.

Time: 1 hour before boots on the ground

Purpose: “Top off” fuel stores to make them readily available for active brain and muscles. Pre-fueling guidelines include 1–4 grams of carb/kg 1–4 hours prior to activity—adjust to personal preference, experience, and schedule.

Fuel: Suggest Warfighters eat a meal of 1–2 grams of carb/kg approximately 1 hour before the march. Avoiding unfamiliar foods and limiting ones high in fiber, fat, and protein help prevent GI distress.

Fluid: Warfighters should consume 14–22 fl oz water.

Caffeine: If desired, Service Members can include 200 mg caffeine (16-oz coffee, 2 pieces of caffeinated gum or mints)

Time: During the march

Purpose: Provide ongoing fuel, in the form of carbs, to keep feeding the brain and working muscles. Focus on simple carbs because these are the most easily and readily absorbed. Also, regular fluid intake helps with maintaining hydration.

Fuel: For training up to 3 hours, Warfighters should consume 30–60 g carb per hour. For training longer than 3 hours, Warfighters should consume up to 90 g carb per hour. For ease, the following options contain about 25 g carb (specific amounts noted). Educate Service Members to pack snacks in small baggies the night before the event.

• 18 gummy bears (26 g carb)
• 25 jelly beans (26 g carb)
• 1 pouch fruit snack (23 g carb)
• ¼ cup raisins (28 g carb)
• 3 Tbsp dried cranberries (24 g carb)
• 2 squeezable fruit pouches (28 g carb)
• 1 sports gel (24 g carb)
• 3 sports chews (24 g carb)
• Energy bar (23 g carb)
• 16 oz sports drinks (29 g carb)

Fluid: Warfighters should drink 16–32 fl oz /hour of water and/or sports drinks. Adjust amounts to environmental conditions and opportunity. Don’t exceed 48 fl oz per hour. Warfighters can stay hydrated and fuel performance with the following options.

• 16 fl oz water bottle
• ½ 1-quart canteen
• 100-oz hydration pack (finish in 4–5 hours)

Time: Recovery meal within 2 hours of completed march

Purpose: Replenish carbohydrate stores, refuel with protein to repair and rebuild muscle, and replace fluid and electrolytes lost through sweat.
Fuel: Warfighters should eat a carb-rich meal with 15–30 g lean protein and healthy fats.

Fluid: Service Members should drink 20–24 fl oz water or sports drink per lb lost during ruck march or hydrate until urine is pale yellow.

For more information, read HPRC’s in-depth guide to nutrient timing.

Ruck march in real time

This is what fueling before, during, and after a ruck march might look like in real time for a 185-lb Warfighter on a 16-mile road march.