Don't Bonk! - Ironman Nutrition Planner

Don't Bonk™ Triathlon Nutrition Planner

Science based approach to a perfect race nutrition plan

Planner v0.05b

It is often said that in triathlon 🍕 nutrition is the fourth discipline. So it is extemely important you nail your carbs, liquid and sodium intake on a race day and get the best results that you worked hard to achieve. This planner will help you to estimate the amount of each and then to put it into practice by selecting the right products for the job. You can read more on how it works in the 🔬 Research section.

Step 1 - Enter your data and target race pace

Race Pace and Distance

Enter race segment distances and expected pace. Be conservative.


Available Liquid Storage

If your bike has hydration system, bottles, or during a run you are using camel-back or you can prepare nutrition in advance for aid stations or special needs bags - put volumes below.

Athlete's Data

Specify your pre-race weight and carb intake rate, sweat rate and sodium loss rate. You can read more details on what to put here in Research section. Keep default if you don't have data or unsure.


Nutrition Selection (Optional)

You can select specific products from Don't Bonk database that will be used to generate your nutrition plan.

Carbohydrate Drink

Carbohydrate Gel or Solid

Electrolyte Drink

Sodium or Sodium tabs

Step 2 - Estimate your target carbohydrates, sodium and liquid requirements

Your 🥇 total race time is estimated at . Here is how much carbohydrates, liquid and sodium you will need:

⏱ Time (hh:mm:ss) 🍌 Carbs (grams) 💦 Liquid (ml) 🧂 Sodium (mgrams)
Pre-Race 15 minutes before 20-60 500 300-500
🏊 Swim 0 0 0
🚲 Bike
🏃 Run
Race Total

Step 3 - Plan your nutrition strategy

Don't bonk suggests planning your nutrition around purpose built sports nutrition products. This will help lower chances of GI distress and improve results. It is important to know what nutritional value each product provides and to plan accordingly.

Don't Bonk algorithm prioritizes carbohydrate-rich drink mixes as a main source of carbs, sodium and hydration if necessary storage is provided. If there is no more storage available it will use gels as a back-up. If liquid storage is not enough to hydrate properly it will suggest using Aid Station water measured in standard plastic 200ml cups.

🚲 Bike

Bike is the best time to consume as much nutrition and fluids as possible. You may deviate from your plan and additionally consume some of the running leg nutrition.

🧪 Product (Servings) 🍌 Carbs (grams) 💦 Liquid (ml) 🧂 Sodium (mg)

🏃 Run

It is harder to consume lots of food and fluid during running section due to both logistics and higher stress on GI. Prioritize gels and don't overhydrate.

🧪 Product (Servings) 🍌 Carbs (grams) 💦 Liquid (ml) 🧂 Sodium (mg)