TrailCadence

Best Trail Nutrition for Ultramarathons

Ultramarathon fueling is a different problem than fueling a road marathon. Across 6 to 30 hours of effort, gut tolerance, sweetness fatigue, and sodium balance matter more than peak absorption rate, and the product that carried you to mile 40 may become impossible to swallow by mile 70. These picks are the gels, real-food pouches, and electrolytes the ultramarathon community actually relies on across a full day of racing, chosen for digestibility over long efforts rather than short-course speed.

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Quick answer

GU Energy Gel in 24-packs is the most practical all-day ultramarathon fuel, widely stocked at aid stations with caffeinated options for late-race fatigue. For sensitive guts, Maurten Gel 100 uses hydrogel technology to reduce GI distress, and Spring Energy real-food pouches digest more cleanly than maltodextrin gels once sweetness fatigue sets in deep into a 100-mile race.

Top Pick Precision Fuel and Hydration Direct
Precision Fuel and Hydration PH 1500 Electrolyte Capsules (30-pack) Top Pick
4.7 Editorial score / 5.0

Precision Fuel and Hydration PH 1500 Electrolyte Capsules (30-pack)

Research-backed electrolyte capsules with 1500mg sodium per capsule, used by elite ultramarathon runners for sweat rate-matched replacement.

Best for Serious ultramarathon runners who have experienced cramping or hyponatremia and need research-backed sodium replacement.
  • 1500mg sodium per capsule is the highest-strength option for heavy sweaters
  • Used by UTMB podium athletes and supported by sports science research
  • Available in 250mg, 500mg, and 1000mg strengths for personalized dosing
  • Requires understanding of individual sweat rate for correct dosing
Price $20-$30 Check price on Amazon
Best Value GU Energy Direct
GU Energy Gel 24-Pack Best Value
4.6 Editorial score / 5.0

GU Energy Gel 24-Pack

The trail running gel category standard: 100 calories per gel, 20 flavors including caffeinated options, 24 gels per box.

Best for Runners who want the most proven, widely available gel for training and racing.
  • 100 calories per gel with amino acids and electrolytes included
  • 20 flavor options including caffeinated variants for late-race fatigue
  • Widely available at race aid stations so familiar with your race fuel
  • Standard maltodextrin formula causes GI distress for some runners
Price $45-$55 Check price on Amazon
No. 03 Amazon
Maurten Gel 100 (Box of 12)
4.5 Editorial score / 5.0

Maurten Gel 100 (Box of 12)

Hydrogel-technology race gel used by UTMB elite athletes: neutral taste, 25g carbohydrates per gel, designed to reduce GI distress.

Best for Runners with sensitive guts who have had GI distress with standard gels and want the best-evidenced alternative.
  • Hydrogel technology may reduce stomach irritation versus standard maltodextrin gels
  • Neutral taste without sweetness fatigue on long efforts
  • Used by elite marathon and ultramarathon athletes as a trust signal
  • Most expensive gel option; $3.50 to $4 per unit adds up on a 100-mile
Price $40-$50 Check price on Amazon
No. 04 Amazon
Spring Energy Long Haul Endurance Fuel (Box of 12)
4.4 Editorial score / 5.0

Spring Energy Long Haul Endurance Fuel (Box of 12)

Real food pouches made from brown rice, coconut oil, and banana: easier to digest late in a race than any gel when sweetness fatigue hits.

Best for Runners who transition to real food in the second half of 100-mile races and want a packaged option.
  • Real whole-food ingredients digest more comfortably than synthetic gel formulas for many runners
  • Savory and neutral flavors avoid sweetness fatigue in long races
  • Thicker consistency feels more like actual food, reducing nausea
  • Thicker consistency than gels can be harder to consume at race pace
Price $35-$45 Check price on Amazon
The method

How we chose

We evaluated each option on feel, build quality, and value. Our top pick, Precision Fuel and Hydration PH 1500 Electrolyte Capsules (30-pack), earned the spot. The best electrolyte product for ultramarathon use; evidence-based dosing for serious athletes. The comparison above highlights exactly who each pick is best for.

Related guides

Trail Nutrition: Gels, Food, and Electrolytes

Read

FAQ

Best Trail Nutrition for Ultramarathons: FAQ

How should ultramarathon fueling change over a long race?+

Start with gels while your gut is strongest, then shift toward real food as the hours add up. Most experienced ultramarathon runners use GU or Maurten gels for the first 40 to 50 miles, then transition to Spring Energy pouches or aid-station real food when they can no longer stomach the sweetness of gels. Pair any fuel with a dedicated electrolyte product, since gels alone rarely cover sodium losses on a hot, long day.

Do I need separate electrolytes for an ultramarathon?+

Usually yes. Most gels carry only token sodium, so heavy sweaters and runners in heat need a dedicated electrolyte product alongside their fuel. Precision Fuel and Hydration capsules deliver research-backed sodium dosing matched to real sweat losses, which is why ultramarathon runners who cramp or have had hyponatremia rely on them. Plan electrolytes as a separate line item from calories, not as something a gel quietly handles for you.