Carbohydrates are an incredibly important fuel source. Not just for your muscles, cells and tissues which provide the body with energy to move, but also for the brain and central nervous system to function correctly. They are an essential part of day to day life and should be consumed with most meals. Unfortunately they have been getting a bad wrap of late. We need them, it is as simple as that!

With so many diets and short-term fixes relying on simply cutting out carbohydrates, I thought it would be valuable to help give a bit of background and understanding around why they are such an important part of day to day life.

Continue to read more about why carbohydrates are so important and the role they play in optimum training nutrition.


How do carbohydrates work?


Each gram of carbohydrate that you eat provides you with 4 calories of energy. Any carbohydrate that enters the body is broken down to its simplest form of sugar called glucose or blood sugar. This can be used immediately, or stored in the liver or muscles for later use. There is a relatively limited amount of carbs that can be stored as glycogen in the body’s liver and muscle cells, at 100g and 400g, respectively.

The amount of glucose in your bloodstream along with the amount of glycogen stored in the muscles and liver has a direct effect on exercise performance!

Consuming a high-carbohydrate diet to replenish muscle glycogen stores will promote optimal adaption to training. This means prioritising carbs such as bread, pasta, rice, oats, cereals fruits and vegetables (in acceptable amounts of course) around your PT sessions will allow you push even harder the next day at the gym and get more gains.

If carbohydrate needs aren’t met, the glycogen stores will become reduced. This will result in fatigue and reduced work rates, impaired skill and concentration and perception of effort.


ESSENTIALLY, low carbohydrate intake = limited capacity for high intensity exercise.


Traditionally, 50% of our daily calories were advised to be received as carbohydrate. More recently, the advice has shifted to focusing this number on bodyweight and exercise intensity. This is so that we can adequately be fuelled and recover without adding excess weight. Those who train up to 1 hour a day are likely to require is 3-5g/kg bodyweight when completing low intensity exercise such as stretching and mobility, or 5-7g carbohydrates/kg of body weight for moderate intensity training.

For example, if you weigh 70kg a day and train hard for 45 minutes to an hour a day your carbohydrate intake = (70×5) – (70×7) = 150-490g/day.

It is important to note again that the body only has a limited capacity for storing carbs for fuel, so once those tanks are full carbs will be stored in excess- so don’t overdo it!



What are the different types of carbohydrates?


Carbohydrates are broken up into three main categories:

  • Simple (sugars)
  • Complex (starches and fibres).


Essentially referring to the number of sugar units in the molecule. Simple sugars consist of 1 or 2 sugar units, monosaccharides or disaccharides.

Complex carbohydrates are much larger molecules. They consist of hundred or thousands of sugar units joined together. Starches which the body is required to break down to use for energy falls into this bracket. This includes foods such as bread, cereal and pasta.

We also have dietary fibre that will aid smooth gastro intestinal function. It may help lower cholesterol which will be delved into deeper further down.



I thought sugar was harmful for health?


Sugar is a carbohydrate meaning that it is an energy source for the body. Despite the negative press around it, small amounts of sugar are unlikely to cause harm. Provided you time your sugar intake around exercise, it may even aid your performance. It can also promote rapid glycogen refuelling during the 2-hour window post intense exercise.

The main problem that studies have shown associated with sugar is that an excessive amount may result in dental issues such as experiencing tooth decay. Sugar also has no real nutritional value with the exception of providing energy. As it may make food and drinks more enjoyable it can also make them easy to over-consume.

Even though it is not uniquely fattening, it can contribute to an overall over-consumption of calories. This is especially true as it is often combined with lots of fat in the form of cakes, snacks and biscuits.

Although high intakes have been linked to obesity and type 2 diabetes, the studies have shown that the main contributor is excess calories rather than the sugar itself. Another claim often highlighted is the idea that high sugar intakes can cause insulin resistance. This in turn causes the cells of the body to become less responsive to insulin and more likely to store fat.

Regular exercise however, lessens the effects of sugar as it increases insulin sensitivity and improves glucose uptake by body cells. The advisements of 10% of total sugar from the world health organisation is designed to reduce the risk of obesity and improve dental health, but I do think it has its time and place!



Eat more fibre!


Fibre is a complex carbohydrate, mainly found in plants which cannot be digested by the body. Fibre is important for gut health by allowing a smooth passage for food through the digestive system as well as feeding healthy microorganisms that live in the bowel.

A high fibre diet helps to reduce the risk of:

  • Obesity
  • Type 2 diabetes
  • Heart disease
  • Stroke
  • Constipation.


Fibre-rich foods are also beneficial for weight control. This is due to the fact they are more filling, take longer to digest and increase satiety or the ‘full’ feeling.

Sources of insoluble fibre that help to speed the passage of food through the gut include:

  • Wholegrain bread
  • Pasta
  • Rice
  • Vegetables.


Soluble fibre sound in beans, lentils, oats, fruit and vegetables and nuts can reduce LDL cholesterol levels. They can also aid to control blood glucose levels by slowing the absorption. 30g of fibre a day is recommended for adults by the UKs Scientific Advisory Committee on Nutrition, however most adults do not even reach 20g.

If there is one thing you take from this, eat more wholegrains, fruit and vegetables and seeds. You will start feeling and looking better today!



In Summary


Carbohydrates are perhaps the most important macronutrient, especially when it comes to training. There are many different forms of carbs and there is a time and place for them all. They provide us with an energy source, and a very important one at that.

It is advised to eat 1-4g of carbs / kg of bodyweight in the 1-4 hours pre-workout.

This will:

  • Increase performance during your session
  • Reduce fatigue
  • Produce optimal cognitive function
  • Allow adaption to exercise.


It is just as important to replenish your depleted glycogen stores post exercise so that your body can adapt to the stress it was put under in the session and allow you to push harder next time.

Without a substantial amount of carbs 1-4 hours post-workout, you will be more prone to fatigue, and future under-performance.

So eat your carbs, keep the body fuelled and achieve your maximum potential in the gym!!



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