Carbohydrates are the most common, convenient and rapid source of energy. Carbohydrates are key for energy levels and crucial for optimal performance. Limited energy = poor performance.
The two main types of carbohydrate are complex carbohydrates and simple sugars. Complex carbohydrates release energy slow and steady. Simple sugars such as maltodextrin, fructose and dextrose provide a rapid release of energy, and are often taken before and after exercise to replenish muscles.