Nutrition Supplement: Vitamins and Diet for Athletic Performance

Vitamins minerals and more: Safely using vitamin supplements and a well-balanced diet can enhance athletic performance.


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Whether you’re a triathlete in training or a lunch-hour walker, vitamins and other dietary supplements may improve your performance—if they’re incorporated into a balanced diet and used with common sense.

Most health professionals agree that the foundation for optimal athletic performance of any degree is a well-balanced and varied diet, along with adequate sleep and proper training techniques.

Once this regimen is in place, dietary supplements may help some people enhance their performance. Although the wrong ones can interfere with nutrient absorption, the proper dietary supplements can help the body recover quickly from exercise.

The impact of exercise

During the first four hours of exercise, the body runs primarily on carbohydrates and fats. Fatty acids provide fuel during exercise of low to moderate intensity, and carbohydrates help maintain blood sugar levels while the body is producing energy. When we run out of carbohydrates we become fatigued, so it’s important to replenish carbohydrates during and after exercise.

Edmund Burke, Ph.D., director of the exercise science program at the University of Colorado’s Colorado Springs campus, says advance planning can help you avoid running out of fuel. Say, for example, that you plan to take a two-hour hike. Eat a balanced meal two to three hours before the hike, he suggests. About thirty minutes before you start off, eat half a sports bar and drink 8 to 12 ounces of water. During exercise lasting one hour or less, water is the best drink to keep yourself balanced, Burke says. If you use special sports beverages instead, their added carbohydrates and electrolytes will just be lost through perspiration. For longer exercise periods though, sports beverages are recommended, and you should also take along some fuel such as raisins, oranges, fig bars or the new carbohydrate gels to maintain carbohydrate levels during your workout. Once you’ve finished exercising, he says, replenish your carbohydrate reserves so that your muscles can recover more quickly.

Carbohydrate intake is important for participants in activities of all intensities, but especially for endurance sports such as bicycling, cross-country skiing, and running. Ann Grandjean, Ph.D., director of the International Center for Sports Nutrition in Omaha, Nebraska, recommends that athletes who train aerobically for 60 to 90 minutes a day take in a daily dose of 4 to 5 g of carbohydrates per pound of body weight to maintain levels of glycogen, the body’s major carbohydrate reserve.

If you wish to use supplements, incorporate them into your workout program one at a time in order to gauge how and whether they work.

The other fuel source

Protein builds muscles and endurance, so maintaining protein levels is especially important for athletes involved in strength sports such as downhill skiing, weight-lifting, and tennis. However, before supplementing the diet with protein powders or amino acids, the building blocks of protein, you should know the actual amount of protein you need for your body weight. Only long and intense exercising on a regular basis should require protein beyond that provided by your regular diet. Protein powders mixed with liquid make excellent meals when you don’t have time to cook, but fish, chicken, legumes, and other whole foods offer the best possible ­protein sources.

To determine how many grams of protein your body requires each day, multiply your weight ­by 0.36, the current RDA for protein per pound of body weight.

Wise use

If you wish to use supplements, Grandjean recommends incorporating them into your workout program one at a time in order to gauge how and whether they work. Allow six weeks of observation between the supplements, she says, and don’t begin taking a new supplement immediately before a competition or important sporting event unless you’ve tried it during training.

The following list describes some supplements commonly used by athletes and recreational exercisers. For information about dosages, which supplements to take, and whether to take them at all, consult your health-care provider.

• Antioxidants such as vitamins E and C and beta-carotene (a vitamin A precursor) are used by some athletes to offset the increased number of free radicals entering the body during exercise, when oxygen intake is high.

• Minerals such as zinc and calcium are essential to good health. For those who exercise heavily or whose diets are deficient in these minerals, supplements may be required. Zinc activates superoxide dismutase, the body’s antioxidant enzyme, or detoxifier, and can be drained during long, intensive training. Calcium helps to maintain strong bones and teeth and effective muscle performance. Meeting your Recommended Daily Allowance of calcium (between 800 and 1,500 mg for adults depending on age and sex) through a balanced diet can help prevent stress fractures.

• Electrolytes such as sodium, magnesium, and chloride are known as essential minerals—those that the body requires to operate efficiently but cannot manufacture. These electrolytes regulate the balance of fluids and may be depleted through perspiration, which in turn can lead to heatstroke, leg cramping, and mental confusion. Electrolyte rehydration drinks are specifically formulated to replace these minerals and are recommended for heavy exercisers. For people who exercise at lower intensities, sodium may be the only electrolyte depleted. But that doesn’t mean you should increase your salt intake. Rather, make sure you’re eating a balanced diet that includes iron, sodium, and other minerals, because they all need each other to work efficiently.

• Metabolic optimisers are drinks consisting primarily of carbohydrates with some protein, fat, vitamins, and minerals. They are specifically designed to boost muscle recovery after exercising by replenishing depleted glycogen stores and are used mainly by endurance athletes. Burke says the combination of protein and carbohydrates helps repair muscles more effectively than carbohydrates alone.

• Creatine is produced from amino acids found in plants, meat, and fish. Muscles use creatine to make creatine phosphate, their source of performance energy. Creatine supplements are designed to increase creatine phosphate levels and are often used by athletes in sports events such as sprints or boxing, where short bursts of energy are required. However, Grandjean advises, those who are exercising to lose weight may wish to avoid creatine because it can increase muscle mass and overall weight by three to five pounds.

“Nutrition Supplement: Vitamins, minerals, and more” is offered as a bimonthly supplement to Herbs for Health and is written by Monica Emerich and Elizabeth Bertani of Natural Information, 2888 Bluff Street, Suite 301, Boulder, Colorado, 80301. Design by Bren Frisch. “Nutrition Supplement” is offered as an educational service, not a source of medical advice or guide for self-medication. Please consult a qualified health-care professional for treatment of any serious health problems.