By Kenneth Cayce, IV, M.D.
Nutrition is an important aspect of sports performance. Proper nutrition helps athletes perform at their peak output, recover quickly from an injury, and reach their performance expectations faster.
Calories
Many young athletes, especially females, believe they should reduce calories to help them lose weight allowing them to ultimately perform better in their sport. Actually the amount of calories needed depends on the type of exercise you’re doing and the level of intensity.
Sports and exercise activities are classified into low, moderate and high intensity levels. Low intensity is defined as daily activity and is not associated with exercise while moderate intensity is defined as walking, cycling, skiing, playing tennis, and dancing. High intensity exercise is defined as playing basketball, football, and soccer. As your level of intensity increases, caloric intake should increase accordingly. Level of intensity can vary, as well as the amount of time the athlete is performing at each level.
When calculating caloric intake needed per day, the duration of activity, or endurance, is often one of the most important factors. Most calculations are based on endurance.
Endurance athletes, such as distance runners and swimmers should intake about 25 calories per pound of body weight per day. Male strength and body builders should intake 15 to 27 calories per pound of body weight per day, while females should intake and 14 to 20 calories per pound body weight per day. For example, a 140 pound male distance runner would require approximately 3500 calories per day sustain this level of activity, based on 25 calories per pound per day.
Carbohydrates
Carbohydrates are the main source of energy for short duration/high intensity exercise. Carbohydrates are classified based on the glycemic index (GI). The glycemic index categorizes carbohydrates by how quickly they are digested and absorbed in the blood stream, resulting in an increase in blood sugar levels. This increase in blood sugar can lead to quick, short bursts of energy. The glycemic index is classified as low, intermediate or high. Athletes training for longer than one hour should ingest approximately 60-70% of their total daily calories in the form of carbohydrates. Athletes training for less than one hour do not need to consume these larger carbohydrate loads. To calculate carbohydrate needs, the total daily caloric requirement must first be calculated. As in the previous example, a 140 pound male distance runner (endurance athlete) requires approximately 3500calories/day to satisfy his caloric needs; therefore, 60-70%, or 2100 to 2450 calories per day should be in carbohydrate form.
Proteins
Protein requirements should be individualized based on the type and amount of training you are doing. Proteins should contribute about 5 to 10% of the total energy needs of an athlete. High protein intake for the male endurance athlete should be 0.5 to 0.7 grams of protein per pound body weight per day while females should ingest approximately 10 to 20% less. In the early stages of training for non-endurance training individuals, the athlete should consume 0.7 to 0.8 grams of protein per pound body weight per day, and for maintenance training, the athlete should consume 0.5 to 0.6 grams per pound body weight per day. For athletes wishing to increase muscle mass, these individuals should ingest 0.5 to 0.8 grams per pound body weight per day. Studies have demonstrated protein consumption greater than 1 gram per pound body weight per day does not build muscle mass or increase athletic performance. In order to calculate protein needs, as in the previous example, a 140 pound male distance runner competing for greater than one hour requires 70 to 98 grams of protein per day, based on 0.5 to 0.7 grams protein per pound of body weight.
Fats
Fats are the body’s largest store of potential energy. The energy from fats is double the amount of proteins and carbohydrates. Fat consumption should not provide more than 30% of the total calories per day. This is the main source of energy for long duration/high intensity exercise.
Vitamins
Vitamins and minerals are important, sometimes overlooked in an athlete’s diet. Studies indicate deficiencies in the B vitamins decrease athletic performance. When an athlete starts taking vitamins and minerals, sports performance has increased. Additionally, iron deficiencies, most often seen in female athletes, is the most common nutrient deficiency occurring in 30 to 50% of athletes. Iron deficiency has been shown to impact sports performance as a result of decreased oxygen delivery to the muscles. Zinc deficiency has also been noted in female athletes and is estimated that 50% of female distance runners have zinc deficiency.
Pre-competition Meals
Your pre-competition nutritional status is an important part of your training to maximize performance your sport. The pre-competition meal is based on the length of your events and the energy you need for your particular sport. For endurance events (lasting longer than 60 minutes or multiple events), carbohydrate loading, “carbo load”, is used in many pre-game meals. I recommend you reduce your level of training about a week prior to your competition and continue to eat a moderate to high carbohydrate diet. Three to four days prior to your competition, increase your carbohydrate intake until carbohydrates compose approximately 70 to 80% of the daily calories in your diet. For short events (lasting less than 60 minutes), carbohydrate loading should not be used and you should continue on your normal diet while still decreasing the level of training. Carbohydrate loading in short events may actually be a disadvantage due to the increase in weight gain by water and carbohydrate storage.
Some sports require athletes perform many events in one day. In these sports, it is important that the athlete replace fluids and restore carbohydrate levels prior to the next event. If the time between events is 2 to 3 hours, the athlete may be able to eat solid foods as well as drink fluids. If it is less than 2 hours, then fluids containing carbohydrates, such as fruit juices and sports drinks high in carbohydrates, are preferred.
Sports Enhancement Supplements
There has been a lot of discussion about ergogenic aids (creatine, caffeine, bee pollen, ma huang, coenzyme Q, pyruvate, etc.) as sports enhancement supplements. Few products have been supported by research and some provide no benefit at all, while placing the athlete at risk for potential side effects. You should research each supplement and talk to your physician before starting any supplements and focus on the safety, efficacy, potency, and legality of the product prior to taking the supplement.
Kenneth Cayce, IV, M.D., is a Primary Care/Sports Medicine Physician at Cincinnati SportsMedicine and Orthopedic Center. Dr. Cayce is currently accepting new patients by calling (513) 891-3200 for an appointment.
