ZONING OUT

High Protein or High Carbohydrates; and, the winner is . . .

Everyone seems to be talking about "The Zone" diet or the 40-30-30 eating plan. (40% carbohydrates, 30% protein, and 30% fat).

Is this really a healthy way to eat and will it really improve athletic performance? No . . .

The Zone diet, by Barry Sears, Ph.D., is a diet that is based on the premise that a person should eat an equal percentage of protein and fat in the diet, with only a slightly higher amount of carbohydrate. This, in turn, says the author, will help people feel great, lose weight, perform better, and cure everything from heart disease to cancer. Although in his book, he refers to studies he has completed, there are no references listed, so these studies were not even published! This discredits the research accomplished.

A few points:

• Dr. Sears says that foods like pasta and bananas should be avoided or not consumed very much! He has a list of foods that he would prefer people to exclude! That is the first clue to not begin the Zone diet.
• Carbohydrates and insulin do not make an athlete fat. (Insulin is the hormone in our bodies that increases after we eat, and helps put glucose, the blood sugar from carbohydrates, into our bodies' cells.) Paying attention to total caloric intake is the key to maintain, gain, or lose weight.
• High protein, low carbohydrate diets do not improve the body's fat-burning abilities. In fact, too much protein can lead to calcium loss, and then, bone loss, which is especially a concern in female athletes.
• Carbohydrates are needed for strong athletic performance. The storage form of carbohydrates, glycogen, is used for energy. The body needs to be fueled so that it has the glycogen available for an athlete's work-outs and competition.
• A well-balanced diet, with protein, fat, and carbohydrate at every meal is the key to both optimal performance and health. This means that about 60% of total calories should be derived from carbohydrate foods, 30% or less from fat, and 10-15% from protein.

SPORTS DRINKS, BARS, OR GELS: WHICH ARE BEST?

There are so many products out there that claim they will enhance athletic performance. Three commonly used products are: sports drinks, energy bars, and energy gels. Are there benefits to using one over the other? Let's take a look . . .

Research has been done on all of the above products. Keep in mind; however, there are many brands of each product, and research may not have been conducted on all products sold. In general, using a sports drink has been shown to not only improve performance, but, in one study, runners who drank the sports drink ran faster and felt that the race was easier compared to runners who drank a placebo. Note: It is important that a placebo is used in studies in order to be sure that the changes that a researcher observes are due to the effects of the intervention, not just by chance.

As far as energy gels are concerned, research has also shown that they may be helpful for athletes, too. A recent study conducted at California State University at Sacramento compared the use of a gel to a placebo. Although the researchers did not assess performance, they did report that there were higher levels of blood glucose (sugar) in the athletes who consumed the gel compared to the placebo group. One can speculate that this higher blood glucose will be used for energy, and thus, spare stored carbohydrate, called "glycogen ", in the muscle. Since the gels do not provide fluids, it is important to drink plenty of fluids, as well.

How do energy bars rate? Well, several researchers have investigated the effectiveness of solid versus liquid carbohydrates. It doesnít seem to matter if you take in solid or liquid carbohydrates, but, it does matter that you also drink water with solid carbohydrates. If athletes like the taste of energy bars, it may be worthwhile for athletes to try them; since they are convenient and athletes can keep several energy bars in their sports bag for quick energy boosts.

Sports drinks provide both energy and fluid and may be best for some individuals who either dislike the taste of energy gels or bars, or who cannot handle consuming semi-solid or solid forms of carbohydrates, respectively, when they practice or compete. As mentioned above, energy gels and bars have shown positive results for athletes in studies, but it must be emphasized that water still needs to be consumed. As a guideline, an athlete should consume between 5 to 12 ounces of water every 15 minutes. For activity lasting less than 1 hour, water alone is sufficient. Strenous activity lasting over an hour requires both fluid and energy replacement (15-30 grams of carbohydrate every 1/2 hour, which tranlates to 8-10 ounces of sports drink, 1 standard-size gel packet, or 1/2 of an energy bar). Another thing to remember: energy gels and bars may be convenient but are expensive. Furthermore, unless athletes have a taste for energy gels and bars, these products may not be for them. Finally, whenever athletes want to try new dietary regimens, always have them do so during practices, in case athletic performace is negatively affected.

Some researchers have suggested that, depending on how quickly a food is able to raise blood sugar, there may be an effect on performance. This concept is known as glycemic index. This might mean all sources of carbohydrates in food products (including bars, gels, and drinks) are not the same. Weíll discuss glycemic index in more depth in the next issue of the Sports Nutrition Newsletter.

GLYCEMIC INDEX and EXERCISE PERFORMANCE

When it comes to talking abut carbohydrates and their role in enhancing performance, it seems all carbohydrates may not be the same. Even distinguishing between sugars and starches may not be enough. Of late, there has been a lot of talk about a term referred to as "glycemic index". Glycemic index of a food represents how quickly a food is digested and how high your blood glucose (or blood sugar) will rise after you consume that food. The higher the glycemic index, the higher the rise in blood sugar. To accurately test the glycemic index of a food, one would need to ingest a small serving of a carbohydrate food, and then measure the glucose in the blood over a two hour period. The glycemic index is given in terms of a percentage. Pure glucose results in the highest glycemic index: 100%. So, if a food results in a glycemic index of 80, this indicates that eating a small serving of that particular food results in a rise of blood sugar which is 80% as great as consuming the same amount of pure glucose. There are many factors that can influence the glycemic index of a food. These include: the structure of the carbohydrate, the absorption rate, what and when you ate previously, and other substances within that food, like the amount of protein and fat.

So, how can this affect athletic performance? If student-athletes consume lower glycemic index foods throughout the day and up to 1 1/2 hours* before sports activity, they might experience the following positive effects: 1) they might not have a drop in blood sugar prior to training/competition; and, 2) they might have a higher concentration of fat in the blood to use for energy which will then "spare" their muscle glycogen (stored carbohydrate); "sparing" muscle glycogen usually results in less fatigue and better performance. Conversely, consuming moderate to high glycemic index foods after exercise might help to promote muscle glycogen storage, which is good, since muscle glycogen is required for energy.

The effect of glycemic index on performance remains controversial; however, so student-athletes should experiment with foods of different glycemic index during practice times, not during competition. Furthermore, a food with a high glycemic index may not elicit the same increase in blood glucose in all student-athletes.

Here is a list of some high glycemic index foods (greater than 70%):

waffles, bagels, white bread, rice cakes, graham crackers, Rice Krispies, Cheerios, watermelon, baked potatoes, mashed potatoes, carrots, jelly beans, Life Savers, honey.

Here are some moderate glycemic index foods (50% to 70%):

orange juice, Gatorade, rice, oatmeal, Grape Nuts, wheat crackers, whole wheat bread, pineapple, raisins, bananas, grapes.

Here is a list of some low glycemic index foods (less than 50%):

pasta, peas, chick peas, lentils, baked beans, peanuts, pears, oranges, sweetened yogurt, apple juice, skim milk.

* depending on digestibility, low glycemic index foods may be able to be consumed up to 30-60 minutes before sports activity.

To Summarize: High glycemic index foods may enhance performance in athletes and can be useful during and after work-outs or competitions. Low glycemic index foods may be helpful prior to sports activity. However, research is controversial; so, high and low glycemic index foods may not be beneficial for all athletes. If student-athletes want to "experiment" with different types of carbohydrates, encourage them to do so during practices not competition.

EFFECTS OF STRENUOUS PHYSICAL ACTIVITY ON THE ATHLETE'S BODY: HOW NUTRITION CAN HELP RECOVERY

For student-athletes, the day-to-day practices and competitions are rigorous enough; however, back to back competitions (i.e., double-headers, tournament play, track invitationals, etc.) bring additional stress to the student athlete's body. So, what does a student-athlete do with back-to-back competitive events in one day or on consecutive days? There are several considerations.

Hydration: Providing plenty of water throughout the entire day of competition is always imperative. More importantly, providing sports drinks for student-athletes will not only hydrate the student-athletes, but also provide glucose (quick energy). This will help to "spare" the muscle glycogen that is stored; hence, the student-athlete will have more energy and feel less tired with each event. The student-athlete's performance will be impaired if they are not well-hydrated.

Glycogen Stores: Glycogen stores will become depleted if the student-athlete does not replace them. After the competition is completed, the student-athlete should take in about 7 grams of carbohydrate for every pound of body weight. This helps to speed glycogen restoration in the liver and muscles so they will not be tired during the next event. As stated above, sports drinks are a good, quick, easy way to replace glycogen stores. For events scheduled within several hours of each other, a student-athlete will need to experiment with the amount and type of foods and beverages to consume between events. A small meal of about 300 calories, which has high carbohydrates and some protein, is usually well-tolerated by most individuals competing in back-to-back events. For instance, dry cereal and a carton of skim milk, a fruit-flavored yogurt, some fig bars or graham crackers with chocolate milk, a can of Boost, two packets of Carnation Instant Breakfast mixed with water, or a sports bar may work for your student-athletes. These should be consumed with a sports drink and/or water. For events on consecutive days, post-event rehydration and glycogen replacement are important beginning within the first fifteen minutes after the event. Water is the best post-event rehydration fluid and carbohydrate can be replaced with fruit juice, fruit, and/or carbohydrate loading drinks like Ultra Fuel or Gatorlode. Carbohydrate should continue to be a high priority for the next two hours, but student-athletes should not neglect the protein and fats. A meal consisting of pasta, Italian bread and broiled chicken, or thick-crusted pizza with lemonade are a couple of possibilities (see "Quick Tips" for more high carbohydrate "fast food" options.)

Appetite: Some student-athletes can tolerate more food closer to an event than others. Experimenting with what student-athletes can tolerate during practice times rather than at the time of a competition is important to prevent any gastrointestinal upset the day of the big event.

Psychology: Many student-athletes have "rituals" which they perform prior to every competition. These "rituals" may include some food practices. Be sure that these "rituals" are not harmful to the student-athletes or their performance. If you have any questions or concerns about any of your student-athletes' "food rituals", please refer them to the Sports Nutritionist.

Summary: Student-athletes who compete in back-to-back events have a more difficult challenge to rehydrate and refuel themselves. It is important that fluids are constantly available, including sports drinks. Additionally, it is important that the student-athlete consume some more substantial foods (in solid or liquid form) before they compete. This helps to speed glycogen restoration in the liver and muscles. Remember: hydration, replenishing glycogen stores, appetite, and psychology are all important considerations. Taking them all into consideration can help the student-athlete's performance tremendously.

A Final Note: High fat, empty-calorie foods and beverages like candy bars, pastries, carbonated beverages, etc. immediately after an event may not supply the proper amounts of carbohydrate, vitamins, minerals, and fluids to enhance recovery. In addition, alcohol slows down the recovery process and may increase the risk of injury or fatigue.