Carbohydrates (CHO) are one of the three macronutrients found in foods alongside protein and fat. The body converts CHO to glucose, which is stored in the liver and muscles as glycogen to be used as energy when needed (e.g. when you exercise). Full glycogen stores are important to sustain high intensity exercise and prolong fatigue. This can be achieved by ensuring your diet contains adequate amounts of CHO. General fuelling for endurance training requires 7-12g CHO/kg body weight per day depending on the intensity and duration of the training.