We recommend that 60-70% of an athlete's daily calories come from carbohydrates. Popular diets recommend pasta and bread be avoided, but carbohydrates are an athlete's most important energy source. Carbohydrates should be the largest part of pre- AND post-exercise meals. Carbohydrates are needed during exercise if it will last more than an hour. Getting carbohydrates during exercise is easiest with a sports drink. An athlete's daily carbohydrate need is 3.5-4.5 grams per pound of body weight.
Additional protein in your diet does not build stronger muscles and excess protein will stress the kidneys and lead to dehydration and calcium loss. Training methods are the main source for building stronger muscles. Studies show that athletes eat more than enough protein, but are deficient in carbohydrates. We recommend that 10-15% of an athlete's daily calories should come from protein. An athlete's daily protein needs is 0.7-0.9 grams per pound of body weight. Protein from food is of higher quality and less expensive than protein from supplements.
Fat should not be eliminated from an athlete’s diet. Fat is important for many of the body's functions, including brain and nerve function. Fat provides essential vitamins A, E, D, K and omega-3 fatty acids and is found mainly in fish and nuts. It decreases inflammation and swelling, and lower cholesterol and blood pressure. We recommend that 20-30% of an athlete's daily calories come from fat.
Body Fat Percentage
People with the lowest body fat percentage are not necessarily the best athletes. Ideal body weight and ideal body fat percentage are not the same for everyone and they depend on your genetics, your body type and your sport. Each athlete will have their own ideal weight and body fat percentage where they function at their best.
Vitamins and Supplements
Vitamins and supplements do not counteract an unhealthy diet and are not a substitute for real food. Supplements are meant to be added to a balanced diet that comes from a variety of foods. Whole foods give you nutrients, vitamins and minerals that are of higher quality than those in vitamin and mineral supplements.
During exercise, the body loses water and salt in the form of sweat. Children are especially vulnerable to dehydration. Drinking a sensible amount of fluids before, during and after exercise can prevent dehydration. Eating a balanced diet helps keep adequate amounts of salt in the body. Research studies have shown that even mild dehydration (losing fluid equivalent to 2-3% of body weight in the form of sweat) can impair athletic performance. In hot weather, water losses are increased and it is important for children to frequently drink water to compensate for fluid losses. Dehydration also makes athletes more vulnerable to heat exhaustion and heat stroke.
What to Drink
For many activities, water is sufficient to replace what is lost from the body during exercise. For high-intensity exercise lasting more than one hour, drinks with added carbohydrates may help delay fatigue and improve performance. Drinks with a 4-8% concentration of carbohydrates work best. Higher concentrations of carbohydrates are hard for the stomach and intestines to absorb during exercise. Most products marketed as sports drinks contain electrolytes (salts) and these products can help replenish salt loss from exercise. However, having your young athlete eat a balanced diet is the best way to make sure that salt lost during sports gets replaced.
Athletes need fluids before, during, and after exercise. We recommend that before exercise, athletes drink 0.12 ounces of water per pound of body weight. During exercise, drink 0.05 ounces of water per pound of body weight. After exercise drink 24 ounces for each pound you lost during exercise, or until your urine is clear, as athletes can lose 2-4 liters of water per hour in sweat.
Sports drinks are a mixture of carbohydrates, electrolytes and water designed to help replenish substances lost during exercise. These drinks generally contain 6-8% carbohydrates and have 50-70 calories per eight ounce serving. Children may find these drinks taste better than plain water and this may encourage them to drink more while they are exercising. However, sports drinks contain sugar and have calories without much nutritional benefit. Consuming beverages with sugar can also lead to dental decay.
Energy drinks are not designed for athletes. They contain caffeine and often have a higher concentration of carbohydrates than sports drinks. The concentration of caffeine in most energy drinks is significantly higher than that of cola and similar to the quantity in brewed coffee. These drinks usually contain 11-15% carbohydrates and 100-140 calories per eight ounce serving. Consuming beverages with high concentrations of carbohydrates during exercise can cause abdominal discomfort and can interfere with the body’s ability to absorb fluids.