Fuelling a workout Part 1 – Carbohydrates

This information is based on a 45-minute, high intensity workout without too much physical exertion for the rest of your day.  This information is general advice and alters depending on your height, weight, physical activity levels, goals, allergies, food intolerances and any disease states or conditions you may have. Please seek individual advice in these circumstances or if you have specific goals in mind.

What we eat can make a huge different to how we perform, our energy and how we recover. We need to consider the type of nutrient and the timing. Today I will be discussing carbohydrates.

Firstly, what is a carbohydrate – we have two types of carbohydrates – simple and complex. Simple carbohydrates are sugars that are quickly digested by the body and provide a quick source of energy. They are found in foods such as fruits, milk, and processed foods like lollies and soft drinks. 

Complex carbohydrates, on the other hand, are made up of long chains of sugar molecules and take longer for the body to break down and digest. They provide a steady source of energy and are found in foods like whole grains, vegetables, and legumes. 

Prior to a 45-minute workout we are thinking more in terms of simple carbohydrates to help us get the most out of our session and prevent fatigue. Your workout won’t wait for your lovely wholegrain, seedy toast to digest – We want that quick energy to power us through. 

Almost every other time of the day we will fill our diet with complex diet that include vegetables, whole grains and are a good source of fibre and vitamins. 

Many people have the pre-conception that carbohydrates are bad or can cause weight gain. And in some cases this may be true but will depend on so many factors. For the most part carbohydrates are not scary and in fact are extremely important for providing energy for workouts plus a range of other functions in our body such as:

• Energy source in the brain, muscles and cells 

• Food for gut bacteria to create a happy and healthy stomach 

• Support liver function

• Improve immunity

• Regulate mood – who feels happier with carbs in their life? Carbohydrates don’t just taste good, they start a chain of actions that leads to serotonin entering the brain. Serotonin is our happy hormone! 

• Help to prevent injuries- carbohydrates help us to retain fluid and hold the extracellular matrix in place.  The extracellular matrix is like a support structure in the body that surrounds and supports our cells and tissues.  

• Prevent overtraining - Repeated days of hard training typically result in an accumulation of fatigue, making it more and more difficult to complete the workouts. it may take 2 weeks or longer to fully recover if you get too far into this stage. 

A high carbohydrate diet cannot prevent the symptoms, but it can reduce them. It will allow athletes to train a little harder for a little longer and it may reduce the risks of becoming overtrained  

So now we know what carbohydrates are and why we need them but how much should you have and when? 

Total in a day: 

Your total dietary intake should be somewhere between 45-65% carbohydrates of all the foods you in in a day. For example, if you need 10000kJ per day, carbohydrates should be between 4500-6500kJ of that. 

We can also work this out in terms of grams per kg/day. For a 45-minute workout you are looking at around 3-5g/kg/day which would equate to 180g-300g per day for a 60kg person. Please note this figure goes up if you are training more than 90 minutes per day 

Prior to your workout: 

The timing of carbohydrates is important when it comes to exercise. Mostly we want to ensure we are having adequate carbohydrates to fuel our workout and prevent fatigue. 

In the case of 45 minutes of exercise we would look at around 1g/kg of bodyweight. So, for our 60kg athlete, we are looking at 60g carbohydrates before a workout (1-2 hours prior). We also want to make sure it’s low in fibre and fat as this delays the release of the carbohydrates for us to use as energy and can lead to stomach disturbances which we don’t want during a workout! Some protein is OK here but not large amounts again due to its digestibility and delaying the release of our energy for the workout. Protein is the hero post-workout which I will discuss in another post. 

In terms of food this would look like something like maybe a banana on a piece of toast, yoghurt and fruit or a fruit and milk smoothie.

During exercise

In exercise under 60 minutes, there is no need for fuelling during the event.

Post Exercise:  

Carbohydrates post workout can help us to repair and recover. 

1. Because Carbohydrates are the body's preferred source of energy during exercise, consuming carbohydrates post workout can help replenish glycogen stores that were depleted during the workout. This can help speed up recovery and reduce muscle fatigue. 

1. Consuming carbohydrates post workout, especially when paired with protein, can help stimulate muscle repair and growth. If your goal is increased muscle then this is super important!

1. Carbohydrates can help reduce muscle soreness and inflammation post workout, leading to faster recovery and improved performance in subsequent workouts. 

1. They can help replenish energy levels and maintain stable blood sugar levels, preventing fatigue and promoting overall well-being. 
   

How much? 

Generally, your usual daily intake is sufficient so you would just continue to eat the amount of carbohydrates you worked out you need in a day broken up into meals across the day. Ideally you would consume some Carbohydrate and Protein within 1 hr post-exercise and again after 2-3 hours. This might look like a protein shake made with milk (carbs and protein – and interestingly milk contains leucine which is our most important amino acid for building muscle). Or a protein powder smoothie mixed with a banana or honey (or other fruit). We don’t need to avoid fibre here either so we could add some spinach or other vegetables to it too. It might be a tub of yoghurt, a protein ball with dates, protein powder and oats or something you can eat on the go. Then ideally your next main meal includes a good dose of carbohydrates and protein too such as some chicken or tofu with brown rice and vegetables, or salmon with sweet potato and broccoli.

So there you have it, go eat some carbs!

Kasey Boorman, Nutritionist