What to eat before a workout is one of the most commonly asked questions, and one of the most important to get right!

The body uses two main fuels to produce energy: carbohydrates and fat. The analogy of thinking of your body as a car is useful here – your metabolism is your engine, using the fuels to produce energy for movement.

The body has a more limited store of carbohydrate (stored as glycogen in the muscles and liver), which is why carb levels needs constant topping up. In comparison, the body’s fat stores are like a huge reservoir.

When the body is exercising at a lower intensity (walking or jogging), it prefers to use fat as its main fuel. This process of breaking down fat into energy (‘fat burning’) is slower, so the demand can be met. As soon as the intensity increases (e.g. HIIT or interval training) it switches to using carbohydrate as the main fuel source, as it can be more rapidly converted into energy.

As soon as we understand when the body requires carbohydrates, it becomes a lot easier to plan when to include them at mealtimes. As with the elite athletes, I work with, it’s not about having a high or low-carb diet, it’s about matching your intake to your activity levels.

There are many considerations which will affect your eating for training, such as your physiology, cultural beliefs, dietary preferences – but initially we just need to focus on two:

1. The Goal

Deciding on your main goal is key as this will affect your fuelling needs. For example, if your goal is to get leaner and lose excess weight, training fasted (before breakfast) or having a low-carb meal before training can prime the body to break down its fat stores and use these as fuel during the workout (‘fat burning’). Athletes call this ‘training low’ – reducing body’s available carbohydrate (glycogen) stores*.

On the other hand, if your goal is to perform at a higher intensity – 10k race, triathlon, football match – the higher intensity exercise will require more carbohydrates to be used as the main fuel.

2. The Activity

As a general rule, you should go in fuelled for the harder, higher intensity workouts. Here are some carb-based recipes

You can then select easier, low intensity workouts to target fat burning. Here are some lower carb recipe options

*It is important to note that ‘training low’ increases the strain on the muscles, which can reduce the training quality of harder sessions and stress the immune system, therefore it should be carefully planned for with appropriate sessions. Effects of fasted-training on bone health also need to be considered when planning.

Finally, although we’ve discussed how to prepare for a workout, your eating over 24 hours is important to achieve your desired result (e.g. creating a calorie deficit to lose weight).