Backyard Ultra Nutrition: What to Eat Between Loops

Nutrition in a backyard ultra is both easier and harder than in a continuous ultramarathon. Easier because you get a guaranteed break every hour to eat in your base camp. Harder because the stop-start rhythm, the open-ended duration, and the progressive gut shutdown create unique fueling challenges that most traditional ultra nutrition advice does not address.

The Hourly Feeding Window

The backyard format gives you a structured advantage that no other ultra format provides: a guaranteed opportunity to eat real food from your own supply every single hour. This fundamentally changes your nutrition approach:

• You do not need to eat on the loop. Unlike a 100-miler where you must fuel while running, backyard runners can do most of their eating during the rest window. Carry a bottle of fluid for the loop, eat at base camp.
• You can eat real food from hour one. The seated rest window between loops allows your gut to process food more efficiently than eating while running. Take advantage of this.
• Timing is critical. Eat as soon as you arrive from your loop — not in the last 2 minutes before the next one. This gives your stomach maximum digestion time before the next bout of exercise.

Calorie and Carb Targets

The research on ultra-endurance nutrition provides clear guidelines, though individual variation is significant:

• Calories: Aim for 250–300 kcal per hour. You will not be able to match your energy expenditure (which averages ~6,800 kcal deficit per day in 24-hour events), but consistent intake prevents catastrophic bonking.
• Carbohydrates: 30–60 grams per hour for the first 24 loops. Beyond 24 loops (100+ miles), research suggests increasing to 50–90 grams per hour using dual-transport formulations (glucose + fructose in a 2:1 or 1:0.8 ratio) to maximize absorption.
• The absorption ceiling: Your gut can only absorb approximately 60–90 grams of carbohydrate per hour under optimal conditions. Eating more does not mean absorbing more — it means GI distress.

Phase-Based Eating

Your nutritional needs and your gut's willingness to cooperate change dramatically as the race progresses. Plan your nutrition in phases:

Phase 1: Loops 1–12 (Hours 0–12)

Your stomach is fresh and cooperative. Take advantage of this window to build a caloric foundation:

• Mix of liquid fuel (sports drink, smoothie) and solid food
• Good options: banana + peanut butter wrap, rice balls, small sandwiches, energy bars
• Focus on carb-rich, moderate-protein foods
• This is the time when eating feels natural — eat consistently even though you may not feel hungry yet

Phase 2: Loops 12–24 (Hours 12–24)

Appetite typically starts to decline. GI tolerance becomes more selective:

• Shift toward softer, easier-to-digest foods: boiled potatoes with salt, ramen broth, mashed sweet potato, rice pudding
• Liquid calories become more important: smoothies, protein shakes, high-calorie drinks
• Savory foods often become more appealing than sweet as taste fatigue sets in
• Warm food during night loops provides psychological comfort and is often easier to digest

Phase 3: Loops 24–36 (Hours 24–36)

The gut is now under significant stress. Blood flow has been diverted away from the digestive system for over a day. Exercise-induced gastrointestinal syndrome (Ex-GIS) is likely:

• Focus on whatever stays down. Flexibility is more important than hitting macro targets.
• Strong options: bone broth, miso soup, flat cola (caffeine + sugar + familiarity), baby food pouches, watermelon
• Small sips and bites — do not try to eat a full meal in one sitting
• Liquid calories and gels may be all your stomach tolerates

Phase 4: Loops 36+ (Hours 36+)

At this point, nutrition becomes pure survival. Eat whatever your body will accept:

• Any calorie is a good calorie
• Warm, salty broth is often the last thing the stomach accepts when everything else fails
• Flat soda (ginger ale, cola) for quick sugar and caffeine
• Ice chips if nausea prevents fluid intake
• Accept that caloric intake will be suboptimal — the goal is maintaining blood sugar, not optimal fueling

Protein for Muscle Protection

Protein intake during ultramarathons has historically been neglected, but current research is clear: consuming 5–10 grams of protein per hour during extended events significantly mitigates the severe catabolism (muscle breakdown) that occurs during prolonged running.

Practical protein sources for backyard ultras:

• Protein shake mixed between loops (whey or plant-based)
• Nut butter on wraps or bread
• Cheese cubes or string cheese
• Jerky or biltong (caution: can be hard to chew when fatigued)
• Milk-based drinks (chocolate milk is a proven recovery fuel)

Do not overthink protein in the early hours — it is most critical after loop 12 when muscle damage accelerates. During training, your daily protein intake should be 1.8–2.5 g/kg/day to support the high training volumes.

Caffeine Periodization

Caffeine is the most powerful legal performance enhancer available to ultra runners. In a backyard ultra, strategic caffeine use can make the difference between surviving the night and collapsing into sleep:

• Loops 1–16 (daytime): Avoid caffeine entirely. Drink water, electrolytes, and decaf beverages. Save caffeine for when you truly need it.
• Loops 16–20 (evening): Begin caffeine intake as darkness falls. Start with moderate doses — 50–100 mg (roughly one small coffee or caffeine tab).
• Loops 20–28 (night): Increase to 100–200 mg per 2–3 loops during the deepest circadian low. Cola, caffeine gels, coffee, or caffeine tablets all work.
• Loops 28+ (second day onward): Continue moderate caffeine use but avoid exceeding 400 mg in any 6-hour block. Over-caffeination causes jitteriness, GI distress, and paradoxically increases the crash when it wears off.

Hydration Without Overdrinking

Exercise-associated hyponatremia (EAH) — dangerously low blood sodium from overdrinking — is a potentially fatal risk in any ultramarathon. In a backyard ultra, the temptation to drink aggressively during rest windows makes this risk particularly relevant.

• Fluid intake: 300–600 mL per hour. Drink to thirst, not to a schedule. Research strongly supports thirst-driven intake over forced drinking.
• Sodium: 600–1,000 mg per liter of fluid for events exceeding 100 miles. Use electrolyte tablets, salt capsules, or sodium-rich foods (broth, salted potatoes, pretzels).
• Monitor yourself: If your fingers or rings feel tight, if you notice unusual puffiness, or if you feel bloated despite not eating much — you may be overhydrating. Reduce fluid intake and increase sodium.
• Weather adjustment: Hot conditions increase sweat rate and fluid needs. Cold conditions reduce both. Adjust accordingly rather than following a fixed drinking plan.

Gut Training Protocol

The most common cause of race-day nutrition failure is a gut that has not been trained to absorb fuel under exercise stress. The science is clear: gut training — practicing eating while running — functionally upregulates intestinal carbohydrate transporters and improves tolerance.

Start gut training 8–12 weeks before your race:

• Practice eating your planned race foods during every long run
• Start with small amounts and gradually increase to your target hourly intake
• Test both liquid and solid nutrition — your stomach may tolerate one better than the other
• Practice eating during format simulations (mini backyards) to replicate the stop-start pattern
• If you experience persistent GI issues, consider a short-term Low FODMAP approach to identify trigger foods — but do not maintain this restrictively long-term as it can lead to energy deficits

The Aid Station Setup

Your personal aid station — the table, cooler, and setup at your base camp — should be organized for speed and simplicity. When you arrive from a loop with 8 minutes of rest, fumbling through bags wastes precious recovery time.

• Pre-portion everything:Pack food into individual loop bags or containers. Each bag contains one loop's worth of food and a fresh bottle of electrolyte drink.
• Group by phase: Separate early race food (wraps, bars, sandwiches) from late race food (broth, soup, soft foods). Label the phases clearly.
• Hot food station: If you have a crew, a small camping stove or thermos with hot broth and ramen is invaluable during night loops.
• The "emergency shelf": Keep a separate supply of universally tolerable foods: flat cola, plain white bread, baby food pouches, saltine crackers. When your primary nutrition fails, these are your fallback.

Sample Hourly Fueling Plans

These are examples — not prescriptions. Adapt to your body, your preferences, and what you have tested in training.

70 kg Runner (~250–300 kcal/hour target)

• Loops 1–12:Half a PB&J sandwich (150 kcal) + banana (100 kcal) + 500 mL sports drink (100 kcal) = ~350 kcal
• Loops 12–24: Rice ball with salt (150 kcal) + protein shake (150 kcal) + 400 mL electrolyte drink (60 kcal) = ~360 kcal
• Loops 24–36: Cup of ramen broth (100 kcal) + gel (100 kcal) + flat cola (100 kcal) + sips of water with sodium = ~300 kcal
• Loops 36+: Whatever stays down. Broth, cola, small bites of potato, gel if tolerated. Target 150–250 kcal/hour minimum.

Key Principles

• Front-load calories in the early hours when your gut works well
• Transition from solid to liquid as the race progresses
• Sweet to savory as taste fatigue develops
• Never skip a feeding — even a few sips of broth is better than nothing
• Track intake if you have crew — they should note what you ate each loop

When Nothing Stays Down

Despite perfect preparation, there will likely come a point where your stomach revolts. Exercise-induced GI syndrome (Ex-GIS) causes the gut lining to become permeable under prolonged exercise stress, triggering nausea, cramping, and vomiting.

When this happens:

• Slow your loop pace. Walking more reduces the physical stress on the gut and allows more blood flow to return to the digestive system.
• Go liquid only. Stop all solid food. Sip small amounts of broth, flat cola, or diluted sports drink every few minutes rather than trying to drink a full cup at once.
• Ice chips. If even liquid triggers nausea, sucking on ice chips provides slow hydration without overwhelming the stomach.
• Wait it out.GI distress in ultras is often cyclical. A bad loop does not mean a bad race. Many runners experience 2–3 hours of severe nausea that resolves on its own, especially after sunrise when the body's circadian rhythm normalizes.
• Anti-nausea medication: Some races allow and some runners carry anti-nausea medication. Discuss this with your doctor before the race — not during it.