IRONMAN 70.3 Rio de Janeiro fuel plan: carbs, fluid and sodium per hour.

August 8, 2027, Rio de Janeiro, Brazil. Set your finish time and the plan follows.

Distance
113 km
Climbing
Not published
Typical temperature
19 to 26 °C · 66 to 79 °F
Aid stations
16

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

70.3 (half distance) · 5 h 30 min

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

Leg by leg (typical splits for this distance)

  • Swim36 minNo fuel
  • Bike2 h 48 min210 g carbs
  • Run1 h 56 min145 g carbs

About 365 g of carbs over the race (bike and run). 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 70.3 (half distance) and expect to finish in 5 h 30 min. 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 365 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, leg by leg, 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 IRONMAN 70.3 Rio de Janeiro.

One lap 1.9 km swim off Copacabana beach, with the first transition at Copacabana Fort. The 90 km bike is 2.5 laps with eight passes through the Marcelo Alencar tunnel, ending at AXIA Marina da Glória. Three lap run to the finish at the marina, on a course that covers much of the Rio 2016 Olympic route.

On course: LIQUIDZ Sports Drink, DUX Gel, bananas, soft drink and salt biscuits on the run. Train with what the course hands out, or carry your own.

KmLegWhat's there
10bikewater, LIQUIDZ Sports Drink, bananas
21.5bikewater, LIQUIDZ Sports Drink, bananas
30bikewater, LIQUIDZ Sports Drink, bananas
46.8bikewater, LIQUIDZ Sports Drink, bananas
55bikewater, LIQUIDZ Sports Drink, bananas
66bikewater, LIQUIDZ Sports Drink, bananas
74.2bikewater, LIQUIDZ Sports Drink, bananas
1.5runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, Paçoquita peanut candy
3.3runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, DUX Gel
5.5runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, Tachão de Ubatuba banana candy
7.8runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, Paçoquita peanut candy
9.6runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, DUX Gel
11.8runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, Tachão de Ubatuba banana candy
14runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, Paçoquita peanut candy
16runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, DUX Gel
18runwater, LIQUIDZ Sports Drink, soft drink, bananas, salt biscuits, Tachão de Ubatuba banana candy

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

Train for it

Train for IRONMAN 70.3 Rio de Janeiro 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.

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Questions

IRONMAN 70.3 Rio de Janeiro: questions.

  • At a typical finish of 5 h 30 min, 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 19 to 26 °C (66 to 79 °F): Average daily low and high in Rio de Janeiro in August (Weather Spark). Heat raises your sweat rate, so do a sweat test in similar weather.

  • The organizer lists 16 aid stations; the table on this page has each one by km. Check the athlete guide in race week, as positions can change.

More races

Fuel plans for races like this one.

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Not medical advice. Memory.fit is not affiliated with IRONMAN 70.3 Rio de Janeiro or its organizer.

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