IRONMAN Switzerland Thun fuel plan: carbs, fluid and sodium per hour.
July 4, 2027, Thun, Switzerland. Set your finish time and the plan follows.
- Distance
- 226 km
- Climbing
- Not published
- Typical temperature
- 12 to 27 °C · 54 to 81 °F
- Aid stations
- 29
Your plan
Ironman (full distance) · 12 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 moreFluid an hour
To thirst
Without a sweat rate the research says drink to thirst. Do the sweat test to get a range.
NATA 2017ACSM 2007Sodium 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 moreLeg by leg (typical splits for this distance)
- Swim1 h 12 minNo fuel
- Bike6 h 7 min460 g carbs
- Run4 h 26 min335 g carbs
About 810 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 Ironman (full distance) and expect to finish in 12 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 810 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.
Gemini, Grok Bot, Dots, Muse and Cue: copy the prompt and paste it in.
With Memory.fit, your AI would already know your sweat rate.
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The course
What to know about IRONMAN Switzerland Thun.
Swim in Lake Thun, then a hilly 180 km bike with steep climbs. Flat run across the bridges and streets of Thun.
On course: Maurten gels and Solid bars, Precision Fuel & Hydration PH 1000 electrolyte drink, cola on the run. Train with what the course hands out, or carry your own.
| Km | Leg | What's there |
|---|---|---|
| 5 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 26 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 49 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 73 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 95 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 116 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 139 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 163 | bike | water, PH 1000, Maurten bars and gels, bananas |
| 0 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 2.6 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 5 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 7.1 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 8.1 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 10.9 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 12.9 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 14.3 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 16.9 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 19.3 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 21.4 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 22.4 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 25.3 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 27.2 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 28.6 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 31.2 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 33.6 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 35.7 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 36.7 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 39.6 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
| 41.4 | run | water, Precision electrolyte drink, cola, Maurten bars and gels, fruit, salty snacks, soup |
Race details checked October 17, 2026 from ironman.com, ironman.com, ironman.com, ironman.com. Courses and aid stations change: check the official page in race week.
Train for it
Train for IRONMAN Switzerland Thun 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.
Questions
IRONMAN Switzerland Thun: questions.
At a typical finish of 12 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.
Typical race day low and high air temperature published by IRONMAN on the race page. run from about 12 to 27 °C (54 to 81 °F). Heat raises your sweat rate, so do a sweat test in similar weather.
The organizer lists 29 aid stations; the table on this page has each one by km. Check the athlete guide in race week, as positions can change.
Not medical advice. Memory.fit is not affiliated with IRONMAN Switzerland Thun or its organizer.
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