What are the values for the female marathon runner example based on?

For the marathon runner, we're using the lowest carbohydrate intake value (from 3 to 5 g per kg of 63kg body weight) because we're assuming that she doesn't train daily, in which case the lowest range corresponds. All the other values in Module 4, Unit 2 are for daily training.

Therefore:

• 3g x 63kg = 189 carb grams
• 5g x 63kg = 315 carb grams

Making her intake range from 189 to 315g carbohydrate a day.

And how did we get to 2079 daily calories (DCN)?

First, we need to get her BMR: 63kg x 22 = 1386 BMR

Then, assuming our marathon runner trains 3+ a week: 1386 x 1.5 PAL = 2079 calories

And that's how we arrived to these hypothetical numbers!

Manual calculations can take time, that's why it's important that you keep practising.

Alternatively, you can access the Sports Nutrition Clinic Toolkit. We have developed the Sports Nutrition Clinic Toolkit which runs the numbers for you, so you can build your personalized client plans a lot faster and help more athletes! See how here, but it's an optional add-on for graduates only.

AUTHOR: Alex Ruani, Research Director

Updated on: 26/10/2026