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Sample from Edition 001

Most Marathoners Fuel at 35 g/h, but the Ceiling Moved to 120

What a 2026 narrative review with original lab data actually supports.

Evidence: expert insight Action: worth testing 9 min read

Marathon-pace, hour two: at 60 g/h carbs were 43% of total energy. At 120 g/h, 65%.

120 g/h is the new ceiling, earned through gut training and body-size scaling, not race-day jumps.

Carb contribution to energy in hour two

60 g/h

43%

90 g/h

51%

120 g/h

65%

In elite marathoners, 120 g/h kept carbohydrate contribution highest in hour two.

What this means for you

Do not copy a pro's 120 g/h plan cold. The number only makes sense with gut training behind it.

Check the label, not the marketing copy. Look for glucose-fructose or maltodextrin-fructose if you are fueling above 60 g/h.

Targets by event

Event Duration Target range Notes

Half marathon 1 to 2 h 30-60 g/h Single-source gel or drink is usually enough.

Marathon 2.5 to 5 h 60-90 g/h, up to 120 if trained Use a glucose-fructose blend above 60 g/h. Aim higher only if you have done the gut work.

Ultra 6 to 24+ h 30-90 g/h Mix drinks, gels, and real food. Your ceiling depends on tolerance.

This is a very small preview of one research paper review. Read the full research paper review here for the full breakdown, the full tables, and practical insights.

Read the free sample edition See the format before joining

// Feature	Free Thursday newsletter	Research Membership
Cost	Free	$99/yr or $9.99/mo Founding rate
Cadence	One short edition every Thursday	One deep edition every Tuesday
Depth	Highlight reel of the week	Three paper breakdowns with the finding, limits, and practical decision
Researcher context	Occasional references in public editions	More source context, citations, and researcher-informed breakdowns where relevant
Searchable library	×No	✓Tagged archive of every Tuesday edition
Training tools	×None	AI Fueling Calculator live, Training Zone and Supplement tools as they ship
Yearly launch bonus	×No	5K, 10K, and half-marathon plans, carb-loading guides, strength resources, gel and sodium charts, and citation-backed cheat sheets. (annual only)
Community	×No	✓Members-only Discord for research drops and member discussion
Honest about uncertainty	✓Yes	✓Yes, limitations flagged on every breakdown

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Most Marathoners Fuel at 35 g/h, but the Ceiling Moved to 120

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