Carbohydrates

Since low levels of muscle glycogen can cause fatigue, female endurance athletes should consume 60-70% of calories from carbohydrates (8-10 grams of carbohydrate per kilogram of body weight daily). Most female endurance athletes consume far less than this and should be encouraged to eat more nutrient-dense, carbohydrate-rich foods; e.g., fruit, vegetables, whole grain breads and cereals, grains, and beans.

The athlete can use the modified carbohydrate loading technique; 5 grams carbohydrate per kilogram for three days, 10 grams carbohydrate per kilogram for three days, tapering training to improve endurance for events lasting longer than 90 minutes. Consuming at least 30-60 grams of carbohydrate per hour during endurance training or competition will also promote endurance.

Because the consumption of carbohydrate immediately after exhaustive exercise enhances glycogen synthesis, athletes who have to recover quickly should consume at least 1.5 grams of carbohydrate per kilogram of body weight within 30 minutes of completing exercise.

Fluids

Female endurance athletes should drink enough fluids to decrease the risk of heat illness and improve performance. They should drink 8-16 ounces of a rapidly absorbed fluid (water or sports drink) 10-15 minutes before exercise, and at least 4-10 ounces every 15-20 minutes during exercise.

Gender per se is no cause to limit exercise in the heat. When men and women exercise at the same relative intensity (e.g., 70% of aerobic capacity), they have the same tolerance to heat.

Calories

Some women athletes do not eat enough to meet the Recommended Dietary Allowance (RDA) of calories for inactive women their age. Since a lower caloric intake is associated with poorer intake of vitamins, minerals, and protein, the athlete's nutritional status may be compromised. The diets of these athletes should be carefully monitored to ensure adequate intake of vitamins, minerals, and proteins.

Calcium

Calcium is an important nutrient whose intake may be inadequate due to low caloric intake and poor food choices. Low calcium intake can contribute to stress fractures and osteoporosis. The athlete should be encouraged to eat low-fat or non-fat dairy products. Female athletes should consume at least 800-1,200 mg of calcium daily (the recommended daily allowance), and amenorrheic athletes, who are especially susceptible to stress fractures, should consume 1,500 mg daily. If supplementation is necessary, calcium carbonate is the best bet.

Iron

Female endurance athletes often have low iron stores because of menstrual blood loss and poor eating habits. Low iron stores increase the risk of anemia and impaired performance. To improve iron intake, the athlete must emphasize animal iron sources, as such iron is absorbed better than the iron from vegetable sources. The consumption of animal and vegetable iron sources together (e.g. meat and bean burrito) increases the absorption of iron from the vegetables.

Because vitamin C also increases iron absorption, good sources of vitamin C (e.g., orange juice) should be consumed with iron-rich foods.

Regular monitoring of iron status via blood tests and dietary iron intake (the RDA is 15 mg) is recommended.

Female athletes who are anemic often require supplements, as it is difficult to overcome anemia through diet alone. Warning: since large doses of iron can be toxic, iron supplements should not be given routinely without medical supervision.