Carbohydrates are a group of organic compounds made of carbons that include sugars, starches, celluloses, and gums. They serve as a major energy source in the diets of animals and humans. They provide fuel for aerobic and anaerobic activity. Carbohydrates provide sustained energy for aerobic activity and immediate energy for anaerobic or high-intensity activities. It is essential that long-distance runners and high-intensity athletes intake adequate carbohydrates before, during, and after activity. The appropriate amount will depend on the length and intensity of the activity. Carbohydrates are needed to burn fat and are metabolic primers. When you eat carbohydrates, they are released into your bloodstream, cause insulin to be released, and provide energy to the cells and the blood. This means that carbohydrates, taken in the right amount and in small amounts, can aid in weight loss as well.