7‑Step Ultramarathon Nutrition Plan to Beat the Bonk

Mid‑race gut cramps, a sudden energy crash, and a race that feels impossible—sound familiar? If you’ve ever “bonked” on a trail because your fuel was a random grab‑bag, this guide gives you a personalized ultramarathon nutrition plan you can test, tweak, and trust on race day. Follow the seven steps below and turn chaotic fueling into a smooth, predictable rhythm that keeps your stomach happy and your legs moving.

The mistake I kept making with my ultra fuel

When I first approached ultra‑fueling I treated it like a snack buffet: a gel, a banana, a handful of pretzels, and a sports drink all at once. My stomach couldn’t decide which fuel to digest, so I ended up with cramps, nausea, and a bonk around mile 40. The core problem was the lack of a ultramarathon nutrition plan—I was guessing on the fly, and the guesses were wild.

The turning point came during a 70‑mile training run where I stuck to three consistent items each hour: a 30‑gram carb gel, a salty bite, and a sip of electrolyte drink. The run felt smooth, my gut stayed calm, and I crossed the finish line smiling. Randomness kills performance; a solid, repeatable plan keeps your body in a predictable rhythm.

Build Your Own Ultramarathon Nutrition Plan

1. Calculate your hourly calorie need

Use a smartwatch or a simple calculator to estimate calories burned per hour on your typical trail pace. Most runners fall between 400–600 calories per hour. Write this number down; it becomes the baseline that prevents both under‑fueling and over‑fueling.

2. Choose a balanced mix of carbs, electrolytes, and real food

• Carbs: Quick‑energy gels or chews (30 g)
• Electrolytes: Salty snacks like pretzels or roasted nuts
• Real food: Half a banana, a bite‑size energy bar, or a slice of peanut‑butter toast

This trio covers the essentials of how to fuel for a 100 mile ultra without overcomplicating your pack.

3. Draft an hourly schedule

Break the race into hour‑long blocks and assign a specific item to each 15‑minute segment:

• 0‑15 min: 30‑g carb gel
• 15‑30 min: 200 ml electrolyte drink
• 30‑45 min: Small salty bite (pretzels or nuts)
• 45‑60 min: Real‑food bite (banana or bar)

Adjust timing based on personal preference, but keep the rhythm consistent so your gut knows what’s coming.

4. Test it on training runs

Start with a 10‑mile run and follow the schedule exactly. Record stomach comfort, energy levels, and any need for extra water. On the next run, swap the gel flavor or try a different salty snack. These small tweaks reveal the best foods for ultramarathon training that truly agree with your system.

5. Refine your hydration strategy for trail ultra

Sip water every 20 minutes instead of gulping large amounts. Add a pinch of sea salt to your bottle during hotter sections to maintain electrolyte balance. Consistency, not volume, is the key to a calm stomach.

6. Keep notes and stay flexible

Carry a small notebook and log every bite, how you felt, and any gut issues. Over weeks you’ll notice patterns—perhaps a rice cake sits better than a granola bar, or you need extra sodium after steep climbs. Use these insights to fine‑tune your ultramarathon nutrition plan.

7. Trust the process, don’t over‑engineer

Stop obsessing over every gram. Listen to your body: eat a little more when hungry, trim back if you feel bloated. Simplicity beats complexity on the trail, and a plan that feels natural will serve you better than a rigid formula.

Wrap‑Up: Your Path to a Bonk‑Free Ultra

A personalized fueling plan takes a handful of test runs, but the payoff is massive: steadier energy, fewer gut woes, and mental confidence that you’ve covered the basics. Begin with just one hour of the schedule on a weekend run, then expand. The more you practice, the more instinctive the fueling becomes, and the less you’ll have to think about it during the ultra.

If this guide helped you, subscribe to the UltraFuel Blog newsletter for more no‑nonsense running tips. Know a teammate still pulling random gels off the shelf? Share this post and help them fuel smarter. Happy trails, and may your next ultra be powered perfectly.