To Eat or Not to Eat, That is the Question?

What should I eat before training?

A common question from athletes.

In 2018 Impey et al. coined the phrase ‘fuel for the work required’.

The study recommended that athletes should tailor their nutrition based on the demands of training.

So using this phrase as a starting point let’s look at some things that you can implement in your own training, specifically;

Pre Training Fueling

To eat or not to eat, that is the question?

Jeffrey Rothchild, Andrew Kilding and Daniel Plews tackled this question in 2020. They reviewed current knowledge on pre-exercise nutrition.

They focused on the metabolic, physiological and performance responses to endurance training.

Depending on exercise duration and intensity they provide a great framework that can help you make better pre exercise nutrition decisions around pre exercise nutrition.

The figure below is adapted from this study and shows this exact framework.

Source: Rothschild, J.A.; Kilding, A.E.; Plews, D.J. What Should I Eat before Exercise? Pre-Exercise Nutrition and the Response to Endurance Exercise: Current Prospective and Future Directions. Nutrients 2020, 12, 3473. https://doi.org/10.3390/nu12113473

Exercise under 90 mins

If exercise is under 90 mins and focused in zones 1 to 3 then you may not need any pre training fuel. These sessions are typically done to help promote fat oxidation.

A lot of athletes do these sessions fasted first thing in the morning.

If you do feel like you need something to sustain you there is some emerging research showing that having a small amount of protein pre exercise will not dampen your fat oxidation.

For exercise greater than 90 mins where the bulk of the work is at threshold or above (Zone 4 & 5) it is recommended to have 0 to 75g of carbohydrate.

This will ensure that you are well fueled going into a hard workout. In these types of workouts the main fuel the body uses is carbohydrate so it’s important to top up on carbohydrate.

Exercise over 90 mins

For exercise over 90mins you need to factor in whether you have an easy longer session planned or whether it is a long endurance session with some performance targets like race pacing etc.

For sessions that are going to be mainly zone 2 and below a pre session meal of up to 75g of carbs and 10 to 30g of protein is a good starting point.

For example if you plan an easy 3 to 4 hour bike ride a bowl of porridge and a boiled egg is easy to make.

If there is a more race pace focus or a longer session with some hard intervals then bring your carbohydrate intake up to 75 to 150gs pre exercise.

For sessions like these you could use this to test some pre race breakfast options to see what works best for you.

As with everything these are guidelines and a starting point. You should play around with some different options until you find what works best for you.

This is a great starting point to begin with. Play around with the recommendations and see what works best for you.