Rio de Janeiro Marathon fuel plan: carbs, fluid and sodium per hour.

May 30, 2027, Rio de Janeiro, Brazil. Set your finish time and the plan follows.

Distance
42.195 km
Climbing
Not published
Typical temperature
21 to 27 °C · 70 to 81 °F
Aid stations
See below

Your numbers

Sport
h:mm, like 5:30
kg
Keeps fluid loss under 2%. Never shared.
ml/h
Don't know it? Work it out
mg/l
From a sweat sodium test. Leave it empty if you haven't done one.
Conditions
Gut training
How used your gut is to taking carbs while you train.

Your plan

Marathon · 4 h

Carbs an hour

75g

The research range for this race is 60 to 90 g; your gut training sets where you start. Above 60 g, use glucose and fructose, about 2:1.

Jeukendrup 2014Viribay 2020+4 more

Fluid an hour

To thirst

Without a sweat rate the research says drink to thirst. Do the sweat test to get a range.

NATA 2017ACSM 2007

Sodium an hour

300 to 1,000mg

Nearer the top in the heat. A sweat sodium test gives you your own number.

Baker 2017NATA 2017+1 more

About 300 g of carbs over the race. That is a 25 g gel every 20 minutes, or the same carbs from drink and chews.

Rehearse it in training first: the gut adapts in 2 to 4 weeks. Costa 2017

Hand it to your AI

Your AI can check these numbers against your training and adjust them. The prompt has your results filled in.

See the prompt

I'm racing a Marathon and expect to finish in 4 h. I haven't measured my sweat rate. Conditions look hot, and my gut is in some training for fueling. A race fuel calculator built on the research (Jeukendrup 2014, the ACSM 2016 position stand) gave me: 75 g carbs an hour (glucose and fructose, about 2:1), about 300 g in total; fluid: drink to thirst, no sweat rate yet; 300 to 1,000 mg sodium an hour. Check this against my training and how my gut has handled fueling, then build my race day plan: what to take and when, with real products I can buy.

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Gemini, Grok Bot, Dots, Muse and Cue: copy the prompt and paste it in.

See the card

With Memory.fit, your AI would already know your sweat rate.

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The course

What to know about Rio de Janeiro Marathon.

A point to point course that starts on Recreio beach and finishes at Aterro do Flamengo. The marathon is the Sunday race of a four day festival, with 5K, 10K and half marathon races on the days before.

Water stations about every 3 km, plus one at the start and one at the finish.

Race details checked November 3, 2026 from maratonadorio.com.br, maratonadorio.com.br, maratonadorio.com.br, static.maratonadorio.com.br, weatherspark.com. Courses and aid stations change: check the official page in race week.

Train for it

Train for Rio de Janeiro Marathon with your AI.

With Memory.fit, your AI reads your real training, sleep and fuel, plans your weeks toward race day and shows the plan in the app.

Build a prompt for your AI

Questions

Rio de Janeiro Marathon: questions.

  • At a typical finish of 4 h, the research range is 60 to 90 g an hour, as glucose and fructose, set by how trained your gut is. Enter your own finish time above for your number.

  • Temperatures run from about 21 to 27 °C (70 to 81 °F): Average daily low and high in Rio de Janeiro in May (Weather Spark). Heat raises your sweat rate, so do a sweat test in similar weather.

  • Water stations about every 3 km, plus one at the start and one at the finish. Check the athlete guide in race week, as positions can change.

More races

Fuel plans for races like this one.

Every race fuel plan →

Not medical advice. Memory.fit is not affiliated with Rio de Janeiro Marathon or its organizer.

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