Ultra Marathon Fueling Planner — 50K to 100 Mile Nutrition Strategy
Plan your complete ultra marathon nutrition: calorie targets, gel phase vs real food phase, aid station strategy, and drop bag checklist for 50K, 50 Mile, 100K, and 100 Mile races.
Your estimated finish time in hours
Fueling Phases
Aid Station Strategy
Refill all fluids. Eat real food if > 4hrs in. Confirm sodium intake on track.
Mid-race check. Transition to real food if not done. Check feet.
Final push. Caffeinated gel here. Manage pace for finish.
Full Drop Bag Checklist
- ✓ 11 NorthLine gels (first 4hr)
- ✓ Real food for remaining hours: rice balls, dates, boiled potato, pretzels
- ✓ Electrolyte tabs or capsules (500mg sodium each)
- ✓ Caffeine gel ×2 (for final 20–25% of race)
- ✓ Anti-nausea medication (ondansetron if prescribed)
- ✓ Body Glide / Vaseline
- ✓ Dry socks and spare shoes at 50% mark
11 gels for the first 4 hours
NorthLine Gold Gels — easy to open at race pace, proven in long-course racing
Why Ultra Nutrition Is Completely Different
Everything you know about marathon fueling changes at hour four. Appetite suppression kicks in, gels become nauseating, glycogen depletion is no longer your primary limiter — and your strategy must shift entirely.
The Two-Phase Approach
Phase 1 (Hours 1–4): The Gel Phase Your gut is fresh, carbohydrate absorption is efficient, and energy demands are high. Run your standard race-nutrition protocol: 60–80g carbs/hr from gels, with water and electrolytes. Don't deviate from what you trained with.
Phase 2 (Hours 4+): The Real Food Phase Around hour four, two things happen: gel fatigue sets in, and your gut begins to slow. The transition to real food is not optional — it's physiological. Athletes who continue forcing gels in late-stage ultras frequently vomit.
| Hour Range | Food Type | Examples | | :--- | :--- | :--- | | 0–4 hrs | Energy gels + electrolytes | NorthLine gels, electrolyte tabs | | 4–8 hrs | Mix of gels + real food | Rice balls, banana, boiled potato | | 8–16 hrs | Primarily real food | Quesadilla, broth, dates, pretzels | | 16+ hrs | Whatever you can stomach | Soup, cola, baby food, anything |
Sodium: The #1 Ultra Priority
Hyponatremia (low blood sodium) is the leading cause of medical withdrawals in ultras. It occurs when runners drink large volumes of plain water without replacing the sodium lost in sweat. Target 750–1,200mg of sodium per hour. Drink to thirst, not to schedule — and always include sodium in your fluids.
Night Section Management
If your finish time extends into darkness, calorie needs continue but appetite worsens. Prepare psychologically and logistically: pack foods you know taste good after dark (often sweet foods become tolerable; savoury becomes preferable in the early hours).
Q: Can I use caffeine in an ultra? A: Yes — strategically. Reserve caffeinated gels for the final 20–25% of the race when fatigue and sleep deprivation peak. Caffeine can carry you through the darkest section of a night ultra.
Q: What if I feel nauseous mid-race? A: Stop solid food temporarily. Drink cold cola or flat sports drink — the simple sugar absorbs easily even in nausea. Reduce pace. Walk through aid stations. Most nausea in ultras is manageable and passes within 20–30 minutes.
Frequently Asked Questions
Q: How many calories do I need for a 100-mile ultra?
A: A 100-mile ultra lasting 24–36 hours requires 8,000–14,000 calories total. However, you can only absorb 200–400 kcal/hr, meaning you will finish in caloric deficit regardless. The goal is to minimise the deficit: consume 300–400 kcal/hr consistently throughout the race.
Q: What should I put in my drop bag?
A: Drop bags are your resupply point. Include: fresh gels (8–10 per bag), real food options (rice balls, dates, PB&J quarters), electrolyte tabs, dry socks, anti-chafe cream, a warm layer if racing at night, and any specific medications or supplements you rely on.
Q: How do I train my gut for an ultra?
A: Progressively increase calorie intake during long training runs over 3–4 months before the race. Start at 30g carbs/hr and work up to your race target. Practice eating real food at race pace. Train your gut on the same products you plan to use on race day — never introduce a new food in an ultra.
Verified Data Sources & Authority References
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