Are carbohydrates important for active people?
When starches or sugars are eaten, the body changes them all to glucose, the only form of carbohydrate used directly by muscles for energy. Whether carbohydrates are in the form of starches (in vegetables and grains), sucrose (table sugar), fructose (found in fruits and juices) or lactose (milk sugar), carbohydrates are digested and ultimately changed to glucose.
The body uses this glucose in the blood for energy. Most glucose is stored as glycogen in the liver and muscles. During exercise glycogen is broken down in the muscles and provides energy. Usually there is enough glycogen in muscles to provide fuel for 90-120 minutes of exercise. Most exercise and sport games do not use up glycogen stores so eating carbohydrates during the activity usually isn't needed. But for some active people, eating or drinking carbohydrates during exercise helps maintain their blood glucose and energy levels.
Most active people need not be concerned with "carbohydrate loading," the special technique of eating a lot of carbohydrates for several days before an endurance event. Instead, focus on getting enough carbohydrates everyday. The best way to ensure plenty of energy for exercise is to eat a nutritious, balanced diet that is high in carbohydrates and low in fat with lots of different foods.
Do active people need extra protein or protein supplements to build muscles? No. Muscles develop from training and exercise. A certain amount of protein is needed to help build the muscles, but a nutritious, balanced diet that includes two or three servings from the meat/bean/egg group (6-7 ounces total) and two to three servings of dairy daily will supply all of the protein that the muscles need. Extra servings of protein in foods or protein supplements do not assist in muscle development. Unlike carbohydrates, protein cannot be stored in the body and any excess will be burned for energy or stored as body fat.