Minerals
Carbohydrate
Carbohydrate is the ultra-premium energy nutrient. Foods high in carbohydrate include pasta, bread, lentils and fruit. When you digest carbohydrate, it becomes blood sugar. Blood sugar is then converted into glycogen, which is stored in your muscles and liver as your body's premium source of energy. However, this high performance fuel burns up quickly and your body does not store it in large amounts. To store enough glycogen for fuel and top performance, you should get 55 to 70 percent of your calories from carbohydrate.
Protein
Protein is essential to build and repair muscles and other tissues, and for synthesizing hormones. Protein from food is broken down into amino acids which are then rebuilt into the protein in muscle and other tissues. Physically active persons need more protein than do more sedentary individuals. Surprisingly, research shows that endurance-training athletes need even more protein than do weight-training athletes. To support your protein demand, only 12 to 15 percent of your calories need to come from protein. In a pinch, protein is also a backup energy source, but don't rely on protein for energy. When you burn protein, it is because you are low on carbohydrates. If you are burning protein, you are actually burning valuable muscle tissue, which weakens your muscles. You can get all the protein you need from food. Protein is found in foods like meat, dried beans and dairy products. You do not need protein supplements to get sufficient protein for top performance. Your daily meals and snacks can easily give you the amount of protein you need, even for intense physical training. Remember too much protein can hurt your training performance. It can dehydrate you and cause a loss of calcium, a mineral important for bone strength.
Water
Water is critical to performance. Your body is more than half water. Water carries nutrients through your bloodstream. It assists digestion and brain function. Water also keeps joints, eyes and air passages moist. During physical activity your muscles heat up. Your body water helps cool them down. This cooling process pulls water out of your body in the form of sweat. If you do not replace body water losses, you become dehydrated. Dehydration significantly affects performance, causing a variety of symptoms from fatigue and disorientation to death. Dehydration can occur quickly so you should drink water often - before, during and after physical activity. If you wait until you are thirsty, you are already dehydrated.
Fat
Fat supplies energy, but it takes a while to kick in. Fat needs more oxygen than carbohydrate to be burned for energy, so fat cannot fuel high-intensity activity. It also takes time for your body to transport fat from your fat cells to your muscles. This means that fat does not fuel quick bursts of activity. However, fat does provide an important fuel source for prolonged activities like long training runs. Unlike glycogen, your body can store more fat than you will ever need.
Fat from foods like cheeseburgers, whole milk, donuts, and chips stays in your stomach longer. This may cause you to feel sluggish, impacting your mental and physical performance. A high fat diet also contributes to obesity and increases your risk of developing heart disease, stroke, and cancer.
Although too much fat in the diet is not a good thing, too little in the diet is also considered harmful. Besides fat being an energy source in endurance activities it also transports fat-soluble vitamins. To take advantage of the good things that fat provides, but to prevent loading up, your diet should limit fat intake to 20 to 25 percent of your daily calorie intake. This would range from 55 grams per day for a less active female to 120 grams per day for an active male. If you have trouble keeping weight on, you can increase your fat intake to 30 percent.
