You need a certain amount of food (calories) to keep your body ticking over, known as your Basal Metabolic Rate (BMR). It varies according to your size and gender; around 1200 calories per day for a woman and 1600 for a man.

Calculate your BMI here:

Dave Savage Sports BMI Calculator

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Your BMI is......

less than 18.5:Underweight
18.5 - 24.9:Normal weight
25 - 29.9:Overweight
30 - 34.9:Class I Obese
35 - 39.9:Class II Obese
40 upwards:Class III Obese

Any additional calories burned thereafter would depend on the amount of activity performed. For example, following one of our training plans, you’re likely to burn between 500 and 1000 calories per hour. Failure to do so would result in premature depletion of our glycogen stores and ‘hitting the wall’.

You will then be unable to sustain the high-intensity exercise long enough to produce the necessary adaptations to muscles, cardiovascular systems and fuel systems.

Calculate your energy usage during a training session here.

Eating strategies

Getting the balance right between what to eat, when to eat and how much to eat may take some time to realise. But when you have a tried and tested ‘formula’, stick with it as your ‘go-to’ routine.

This experimenting is best done around your training as opposed to on race day. You’ll soon know what works out best for you, if you don’t already.

Perhaps your body best responds to having a snack or light breakfast before an early morning swim and another just afterwards as opposed to a full breakfast which may leave you feel bloated.

For short distance events (up to open water sprint), protein is essential. Consider protein supplements if you cannot get enough from your regular diet.

A protein-rich snack two to three hours before your training session is highly recommended. A tuna or chicken sandwich on wholemeal bread and some salad is a cracker! If you like tuna or chicken that is! It will ensure that you have a good protein supply available to start building and repairing your muscles as soon as you finish the session.