Fueling guide
Carbs per hour: what the research says
Sports nutrition research gives carbohydrate intake during exercise in bands by duration. Short sessions of about an hour call for little or none, 1 to 2 hours for 30 to 60 g an hour, and long events for up to 90 g an hour.
These are population numbers from position stands and reviews, not a personal prescription. Your own gut and your own sessions decide what works for you.
Memory.fit does not set the number. Your AI reads your sessions and writes a fuel plan for each one.
The bands by session length
The ACSM, Academy of Nutrition and Dietetics and Dietitians of Canada position statement describes carbohydrate during exercise by duration. A review by Jeukendrup uses the same logic and links the amount to how long you go.
Many studies in trained athletes use these bands as the starting point.
- About 45 to 75 minutes: small amounts, or even a mouth rinse, can help at high intensity.
- 1 to 2 hours: 30 to 60 g an hour.
- 2 to 3 hours: up to 60 to 90 g an hour, from more than one carbohydrate type.
- Over 2.5 to 3 hours: up to 90 g an hour in the reviews, and trials have tested higher.
Why the ceiling moves with carbohydrate type
A single carbohydrate such as glucose is absorbed at roughly 60 g an hour at most. Glucose and fructose use different gut transporters, so together they can take in more. Studies found cyclists performed better on glucose plus fructose than on glucose alone.
A trial of 120 g an hour in endurance athletes looked at what higher intakes do, and reviews suggest the gut can be trained over a few weeks to handle more.
What the numbers do not tell you
Reviews of stomach and gut complaints during exercise show that problems are common and individual. A band is a range in which athletes often do well, not a target you must hit.
Race fuel plans show the same ranges worked out for a finish time, with your own numbers on top.
In your AI
The AI you already use, with your data in Memory.fit.
- ChatGPTChatGPT plans your week, fuels your long sessions and writes it all back to Memory.fit.Set up ChatGPT
- ClaudeClaude writes your plans back to Memory.fit, and asks you before it replaces or removes something you have.Set up Claude
Grok BotGrok Bot plans and reviews from your real training, and can re-plan a week after a bad night's sleep.Set up Grok Bot
MuseMuse plans sessions from your real training and writes them into Memory.fit's Plan.Set up Muse
DotsOpenAI says a dot's background research uses your connected apps read only, so plans are written when you ask in the chat.Set up Dots- GeminiType @ in a Gemini chat and pick Memory.fit to ask about your training. Gemini asks you to allow each session it plans, and planning a whole week is not reliable yet.Set up Gemini
- GrokGrok reads your training, sleep and fuel, and can plan around them.Set up Grok
- Perplexity ComputerPerplexity Computer reads your training in Memory.fit. Whether it writes a plan back isn't checked yet.Set up Perplexity Computer
- Claude CodeClaude Code reads your training and writes the sessions it plans back to Memory.fit, asking before each change unless you allowed it.Set up Claude Code
CueYour Cue agents plan your week and write your fuel plans from your real training, sleep and recovery.Set up Cue
What to send
Copy one, send it to your AI.
“Look at my long ride on Saturday in Memory.fit and write a fuel plan for it, with carbs per hour by the length of the ride.”
Tools:
get_workoutsset_session_fuel_plan“Check what I actually ate on my last three long sessions in Memory.fit and tell me how it compared with the plan.”
Tools:
get_ledgerget_session_fuel_plan“Plan my fueling for the next four weeks in Memory.fit, adding a little carbohydrate in each long session so I can see how my gut handles it.”
Tools:
get_training_planset_session_fuel_plan“Save in Memory.fit that gels with fructose sit well for me and plain glucose drinks do not.”
Tools:
save_memory
Questions
In short.
Position stands give 30 to 60 g an hour for sessions of 1 to 2 hours and up to 90 g an hour for longer ones. Runners often find the top of the range harder on the stomach than cyclists do.
Long events use up the carbohydrate stored in the body, so intake during the event matters more. Reviews link higher intakes to events beyond 2.5 to 3 hours.
They are absorbed by different transporters in the gut. Studies show that using both allows more carbohydrate to be absorbed than glucose alone.
Reviews and a two week trial in runners suggest repeated practice during training can improve how well the gut handles carbohydrate.
No. Your AI reads your sessions and writes the fuel plan. Memory.fit stores it and shows it on the session.
Sources · Checked November 10, 2026
- ACSM, AND and DC joint position statement on nutrition and athletic performance
- Jeukendrup 2014 review of carbohydrate intake during exercise
- Review of multiple transportable carbohydrates and performance
- Cyclists performed better with glucose plus fructose than glucose alone
- Trial of 120 g per hour of carbohydrate in endurance athletes
- Review: the gut can be trained to handle more carbohydrate
- Two weeks of gut training and gut comfort in runners
- Review of stomach and gut complaints during exercise
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