This article is written by Emily from @twicethehealth. We hope that this helps increase your nutrition knowledge.

When it comes to running nutrition and carbohydrates, your mind probably jumps to carbohydrate loading. This is the process of ensuring that you’ve fully loaded your glycogen stores in your muscles and liver ahead of an endurance event to allow for improved aerobic performance. As for carbohydrate availability, this is a relatively new phrase on the block. It refers to, as it says on the tin, the amount of carbohydrate you have available in the body at any given time for fuel and recovery.

Good carbohydrate availability has been linked to improved sporting performance, enhanced recovery, and appetite regulation.

If you have poor carbohydrate availability, this could be due to consuming a low carbohydrate diet or eating your carbohydrate at the wrong time/in just one intake. If you are on a low carbohydrate diet and you are feeling fuelled, rested, and making progress in your training then good for you and crack on if you are happy. However, I would never recommend a low carbohydrate diet to any runner. This is because we fuel running with a mix of carbohydrate and fat on a sliding scale that will vary for each runner. At one end of the scale, when you are running at a threshold pace, you will be using carbohydrates primarily.

At the other end, when you are jogging at Kenyan Shuffle pace you will be tapping into fat for fuel. When in the middle ground, say at a happy tempo pace you will be using a combination of carbohydrate and fat for fuel. As mentioned, this scale will be different for every runner which is why fueling can be a bit of trial and error.

Before someone shouts about anaerobic sprinting being fuelled by phosphocreatine, you are correct. However, if you are doing multiple sprinting reps you will run-out of phosphocreatine after about 10-15 seconds and start to tap into your blood glucose. The majority of people using Runna are training for jogging or middle distance running and further so this is where I will focus this article.

We use carbohydrate as a major fuel for running, so if you have poor carbohydrate availability it can lead to you having a reduced carbohydrate oxidation rate during exercise, which in turn leads to an inability to exercise at high intensity. Not only will your performance be affected but it is also linked to an impaired immune system and fatigue. In severe prolonged cases of poor carbohydrate availability it can lead to REDS (Relative Energy Deficiency in Sport) which comes with a whole host of issues related to health and performance.

It is also important to note that you might be consuming enough energy, but you can still suffer from low carbohydrate availability and be at risk of the above due to not eating enough energy from carbohydrates and/or eating them at the wrong times.

There are some studies suggesting a ‘train low, but compete high’ diet in the aim of promoting training adaptations. It is important to note that the majority of studies are carried out on male elite athletes where carbohydrate mouth rinses and caffeine are used and other sessions are performed at normal to high carbohydrate availability. All I’d ask is that you read the whole article to make sure you have not cherry picked information.

It is not only important to think about short term carbohydrate availability, meaning around a big training session or close to an event/race, but also long term carbohydrate availability, meaning in everyday training and recovery.

Top tips to improve your carbohydrate availability:

Complex carbohydrates are your starchy carbohydrates which contain fibre. Some good examples are grains, pulses, bread, pasta, rice, beans, potatoes, etc. Simple carbohydrates sugar, sweets, corn syrup, fruit, dried fruit, milk etc. The two categories are given their names due to the structure of the molecules. Simple carbohydrates have simple short chains which are fast and easy to break down, thus providing energy quickly. Complex carbohydrates have long complex chains which take longer to break down in the digestive system, and so give a longer slow release of energy.

We hope that can take something from this article. Check out our other nutrition resources.

Emily (one half of @twicethehealth)

ANutr, MSc, BSc