Dispelling myths

Whether a person is a professional football player or exercises only once a week, food is a key factor in athletic performance, but too many advertised products mislead and misinform.

Everyone needs to eat a balanced diet, which provides energy to complete an exercise routine and all the nutrients necessary for tissue growth and replacement after a workout.

People who put their hope in health products that claim to build their muscles and give them stamina often end up with a diet that lacks some important nutrients but has an excessive amount of others. Nutritional practices based upon half-truths and misconceptions can even be dangerous if taken to the extreme.

Here are some of the most common myths about how to get energy according to Dr. Mary K. Bielamowicz, nutritionist with the Texas Agricultural Extension Service.

· Eating more protein helps build more muscle.

Protein is important in building and protecting muscles, but high-protein diets or supplements have not been proven to increase muscle mass.

Without proper exercise, excessive protein is often converted to fat and stored. Excessive protein intake may also strain kidney function.

· Eat a lot of carbohydrates before each workout. A high-carbohydrate diet is not necessary for a regular workout. If preparing for a long distance event (lasting an hour or longer) such as a marathon or bicycle race, a high-carbohydrate diet may be needed -- starting several days before the event.

For events lasting less than 90 minutes, a high-carbohydrate diet for one day can adequately fuel muscles.

· Drinking sports drinks, before and after exercise is essential for replacing lost body fluids.

During activity, perspiration causes loss of water and minerals such as sodium and potassium that are important for normal body function.

Under usual circumstances, the average American diet contains more than enough sodium to make up for losses.

Supplements are not needed unless circumstances are unusual, such as participating in a triathlon in intense heat.

· Consuming foods or beverages high in sugar before exercising provides extra energy. If you eat food high in sugar 30 to 60 minutes before working out, it may actually have a negative effect on your performance.

The short-term energy boost could lead temporarily to hypoglycemia, which limits the brain's ability to use its fuel (calories) to boost muscular function and mental drive. Symptoms of hypoglycemia include feeling light-headed, disoriented, shaky, sweaty and fatigued or having blurred vision and heart palpitations.

· Beverages that contain caffeine and alcohol stimulate the nervous system and provide energy.

Drinks that contain caffeine and alcoholic beverages have dehydration effects, which offer no benefit to a person who works out regularly or an athlete in training.