NUTRITION

Body Composition and Athletic Performance

by Sabine Weber Morris

In search of the perfect body? Athletes are always looking for new and better ways to improve their performance and one way is to obtain the "ideal" body composition. When evaluating body composition, total body weight, percent lean tissue (muscle tissue), percent fat tissue, and total body water is often measured. Most athletes' goals are to increase lean tissue or muscle without gaining weight and decrease fat tissue. An increase in muscle will usually increase strength, power and leanness. Fat tissue will take up more surface area; therefore, an increase in lean tissue without weight change will present a leaner body.

There is a fine line between body composition, performance and athletes who want to attain the perfect body. Appearance often is a concern and it may become the athlete's primary driving force in becoming lean — not improvement in performance. Therefore, for athletes trying to improve their body composition, it is important that it is monitored closely to ensure that too much muscle and weight is not lost. If this happens, it will result in reduced athletic performance, strength and endurance, and increased illness and injury.

Determining Body Composition
Hydrostatic Weighing – Specialized equipment is used where the subject is placed on a chair and weight scale then slowly lowered into water. Underwater weight is read when the subject is immersed in water. The difference between out-of-water weight and underwater weight is how much body fat the subject has. Hydrostatic weighing is most popular in research laboratories because it usually is the most accurate way to read lean tissue. It is not very practical because the equipment costs thousands of dollars.

Skinfolds – Skinfold calipers are used to measure the subcutaneous fat layer under the skin. To get the most accurate readings using this method, the subject should find a person trained in using the calipers, usually a personal trainer or athletic trainer. The same person should be used each time because of the degree of error from person to person.

Bioelectrical Impedance – Most body water is found in lean tissue and water is a good conductor of electricity. Fat is a poor conductor of electricity and it actually hinders electrical flow. Electrodes are attached to the wrist and ankle that measure electrical currents and therefore measure lean and fat tissue in the subject. These machines can often be found in health clubs, or personal trainers and nutritionists will often have a machine.

Body Composition and Performance
Body composition is related to athletic performance. It is widely believed that there are ideal weights and body compositions for specific sports. Recommendations for body composition usually are based on percent body fat and percent lean tissue obtained from measurements of samples from elite performers in various sports. Athletic performance cannot solely be predicted by body composition because body size, structure, training, nutrition and composition all are factors relating to athletic performance.

Problems with Excess Fat
An athlete carrying excess weight may be more prone to injury when performing difficult skills. Excess body fat adds to the load without contributing to the body's force-producing capacity. A lean body is desirable for sports like gymnastics, skating, ski jumping and track and field. A low-body fat may improve athletic performance by improving the strength-to-weight ratio. When more weight is composed of lean tissue or muscle, that is more power-producing than fat tissue.

Problems with Extreme Leanness
The body fat levels that are considered the minimal levels compatible with good health are 5 percent for males and 12 percent for females. When an athlete's weight and body fat drop below these levels there is a decrease in performance and increase in both major and minor illnesses and injuries. Athletes who often strive for extremely low body fat and weight often are those athletes who are at risk of developing eating disorders. This often is more prevalent in sports that are dependent on appearance and leanness, such as skating, gymnastics, dancing, body building and running.

Minimum Body Fat Percentages for Selected Sports
Sport Age Sex Percent
Basketball 25-27 M 7-11
F 20-27
Cycling 20-26 M 8-9
F 13-15
Hockey 22-27 M 13-15
F 18-19
Alpine Skiing 16-22 M 9-11
F 20-21
X-C Skiing 20-26 M 7-13
F 15-22
Soccer 20 M 9-11
F 18-21
Swimming 15-22 M 5-11
F 26-27
Tennis 39-42 M 15-17
F 20-21
Distance Running 20-26 M 5-7
F 15-19
Triathlon 20-26 M 7-8
F 12-13
Body Building 25-29 M 8-14
F 13-14

Achieving your Ideal Body Composition
Athletes trying to excel in sports and achieve an "ideal" body composition should focus on certain areas:
1. Test your body composition. The first goal should not be to lose any lean tissue.
2. Make sure you are participating in a safe training program coupled with a healthy diet. Over-training and poor nutrition both lead to reduced athletic performance.
3. If your plan causes too rapid of a weight loss, you are losing lean tissue or muscle tissue. If your performance doesn't improve when you have achieved your ideal body composition than it may not be the best composition for you.
4. Stick with a body composition where you feel and perform the best. There is no ideal number.

Your Personal Power Bar
1-cup crumbled shredded wheat cereal
1-teaspoon fresh orange zest
1/4-cup raisins
1/4-cup chopped walnuts, pecans, or hulled sunflower seeds
1/3-cup corn or bran flakes
1/2-cup chopped dates or figs
1/2-cup dry sweetener
1/4-cup mashed firm tofu
1/2-cup chopped pitted prunes
1/3-cup vegan graham cracker crumbs

Combine shredded wheat, orange zest, raisins, nuts, flakes and figs. Mix until combined, set aside. In a medium-sized saucepan, combine sweetener, tofu, and prunes. Stir over medium heat for 5 minutes or until mixture thickens. Combine with cereal mixture. Allow mixture to cool. Form into 10 bars (about 4 tablespoons each). Roll each bar in graham cracker crumbs. Place in a plastic storage container and cover tightly. Refrigerate for 2 hours before eating. Bars will stay fresh for five days.

Source: Vegan Meals for One or Two by Chef Nancy Berkoff, RD
Per bar: Calories 144, Carbohydrate 29 grams, protein 3 grams,
fat 3 grams, sodium 45 milligrams. Makes 10 bars

Sabine Weber Morris, MS, RD, CDN (adknutrition@msn.com), is a registered dietitian and certified nutritionist. She is the owner and operator of Adirondack Nutrition Consulting in Lake Placid. Sabine lives in Wilmington and enjoys skiing, snowshoeing, hiking, running, biking and rock climbing.

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