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understanding macronutrients part 1 (Carbohydrates)

All energy comes from three classes of food called macronutrients. These nutrients are better known as carbohydrates, fats and proteins. All three are extremely important to maintain all activity and for general well-being.

In a time where we are bombarded with information on what we should or should not eat, with ever conflicting advice, what do you trust. Thankfully Scientific nutrition for sports has not changed in over 30 years and is the one area of nutrition that’s not contested. Scientific sports nutrition is a well researched subject, with proven dietary strategies, used by all professional athletes. So what do we know about macronutrients?


Of the three, carbohydrates contain the least amount of energy gram for gram, but is the most essential and most important type of fuel for any sports person

From the shortest and most intense type of exercise, to the long distance endurance race, carbohydrates are the only fuel capable of supplying the body with energy at the speed it requires. In the first few minutes of any activity, it is carbohydrate that almost exclusively meets energy demands. In addition, the ability to repeat a sprint at the end of a game or race, to the same high level as at the start of the game relies, in part, on the body's carbohydrate stores.

During lower intensity activities, the body does use FAT, but utilises the carbohydrate as a catalyst to promote the energy release from the breaking down of the fats. The brain and the central nervous system exclusively use glucose as a source of fuel.

So what happens to the carbohydrate stores in your body if you skip an important meal like breakfast?

On average, each of us can potentially store up to 2000 calories worth of carbohydrates. An overnight fast (8 to 12hrs) and a low-carbohydrate diet can dramatically lower these stores. Especially in endurance and long distance activities, the body relies on these stores to provide the energy needed, so if the carbohydrate stores are significantly depleted as a result of an overnight fast, you may not be able to complete the activity.More importantly, a carbohydrate-rich diet can more than double carbohydrate stores. The body's upper limit for carbohydrate storage equates to about 15 grams per kilogram (2.2lbs) of bodyweight. So an 80kg (175lb) person can potentially store up to 1200 grams of carbohydrate or 4800 calories worth of energy - all with just a few dietary modifications.

Understanding the different types of carbohydrates and their role in the human body, determines a sports persons diet and gives an indication of pre, and post workout meals.


This is the most basic unit of carbohydrate. Examples of monosaccharides include fructose (sugar found in fruit) and glucose (also called blood sugar). Cells can use the glucose found in food directly for energy, while fructose is converted to glucose in the liver.


“DI” meaning TWO is a Combination of two monosaccharides. Examples of disaccharides are Sucrose or table sugar, the result of combining glucose and fructose and the sugar in milk, lactose, another disaccharide. The collective name for both monosaccharides and disaccharides is simple sugars. Simple sugars are quickly absorbed by the body and provide a rapid source of energy.

Simple sugars such as fruit and energy drinks are a good food choice to refuel AFTER a long bout of exercise like a race or a marathon when the body's energy stores are low.


As the name suggests, “POLY” meaning many is a combination of hundreds of monosaccharides, starch and fibre are polysaccharides. Nutritionists often refer to polysaccharides as complex carbohydrates. Examples include bread, potatoes, rice and pasta. It takes longer for the body to break these complex structures down so they release their energy over a longer period unlike simple sugars.

Fibre differs from starch in that it cannot be digested and used for energy. It remains an important dietary component and there is a growing connection between lack of fibre and certain degenerative illnesses. A fibre rich diet is even more so important for female athletes and can reduce the risk of bowel cancer.

Starchy complex carbohydrates are the best choice BEFORE intense activity as a pre-workout meal.


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