Vegetarian Athletes

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Word count: 2706

Vegetarian Athletes

Kathrine Himberg

Virginia Tech

Department of Physical Education

Sharpsburg, VA

USA

What do Al Oerter, Martina Navratilova, Paavo Nurmi, Carl Lewis, Desmond Howard, Bill Pearl, Hank Aaron, Andreas Cahling and Edwin Moses have in common? Aside from being champion athletes they are all vegetarians. It takes more than food to make a world class athlete, but aside from physical training and hereditary limits, "no factor plays a bigger role in exercise performance than does nutrition" (4). The American Dietetics Association's position on vegetarian diets in general is that "well planned vegetarian diets are consistent with good nutritional status" (2).

Vegetarian athletes and omnivorous (meat eating) athletes alike need well planned and nutritionally sound diets if they want to make the diet an asset rather than a detriment to athletic performance. This means getting enough calories each day from foods that provide all the necessary vitamins and minerals, sufficient but not too much protein and fat, and enough complex and simple carbohydrates, fiber and water.

For optimum performance it is important consume adequate amounts of nutrients in the days and hours before exercise and competitive events. It is also crucial to replace depleted nutrients after exercise and competition, failure to do so may negatively affect performance in the days that follow.

Definitions

There is no single vegetarian eating pattern, and within the different categories of vegetarianism there are people with nutritionally sound and not so sound dietary habits. In general vegetarians are divided into lacto-vegetarian, lacto-ovo vegetarian and vegan (or "total" vegetarian).

VEGETARIAN:

A person whose diet consists of no meat, fish, seafood or poultry is considered a vegetarian.

LACTO VEGETARIAN:

A vegetarian whose diet contains dairy products.

LACTO-OVO VEGETARIAN:

A vegetarian whose diet contains dairy products and eggs.

VEGAN:

A vegetarian who consumes no animal products. Sometimes referred to as "total" vegetarian.

People are, or become vegetarians for different reasons. The most common reasons include health and well being, religion, ethics and philosophy. The varying degree of abstinence from animal foods such as milk, eggs and cheese is usually determined by the persons reasons for being a vegetarian.

As with any other athlete, the vegetarian athlete needs to meet the United States Recommended Dietary Allowance (US RDA) for all necessary nutrients each day. Athletes have a higher than normal energy requirement depending on their activity and intensity of training. Athletes need to be especially careful to meet their calorie need, as well as the specific requirements for carbohydrates, proteins, fat, vitamins, minerals, water and fiber.

Energy Requirement

The most common nutritional problem among athletes is consuming too few calories in the course of a day. Energy requirements vary greatly between athletes and for each individual athlete during different seasons. Caloric need is affected by age, sex, body surface area, environment, and daily caloric expenditure during exercise. Vegetarian athletes have the same energy requirements as their counterpart non-vegetarian athletes, however they may have a greater difficulty fulfilling their requirements in three meals per day. Vegetarian food is commonly lower in fat and protein, and total calories per meal may be lower. Vegetarian athletes may reach their energy requirement more easily if they eat five to six meals per day, and include some concentrated foods, such as dried fruits, fruit juices, nuts and seeds.

When athletes do not consume enough calories in a day their muscle glycogen stores are depleted, which leads to a quicker onset of fatigue. Thus an important nutritional consideration for all athletes is ensuring adequate intake of calories each day, to avoid negative effects on endurance and performance. This energy intake should consist mainly of complex carbohydrates.

Carbohydrates

Muscle glycogen depletion during exercise occurs at a rate that is dependent on exercise mode, intensity, physical conditioning , environmental temperature and pre-exercise diet (4). A diet high in carbohydrates provides the most easily utilized fuel for exercise. Dietary carbohydrates play a very important role in performance, especially for endurance events, and during periods of heavy training (4).

For any athlete the staple of the diet should be foods high in complex carbohydrates, which promote glycogen storage. The vegetarian diet is normally centered around such foods as pasta, rice, bread and cereal, which are high in complex carbohydrates. Athletes should have at least 60-65% of their daily calories from carbohydrates, 50-55% of these should be from complex carbohydrates, and only about 10% from simple sugars. Endurance athletes may need as much as 70% of their daily calories from carbohydrates. A balanced vegan diet normally fulfills or exceeds these requirements, while a lacto- or lacto-ovo vegetarian diet needs to include adequate amounts of plant based foods, high in complex carbohydrates.

Protein

Studies suggest that athletes need slightly higher levels of protein than the RDA of 0.8 g.kg-1.day-1 for the general population. Endurance athletes may need a higher protein intake, and the recommendation is 1 g.kg-1.day-1 (1). The average American diet consists of about twice that amount. However, even a vegan diet, if it meets the calorie requirement, should reach this increased protein requirement, as long as it includes unrefined grains, legumes, nuts, seeds and vegetables. The requirements for the individual amino acids will be met if the diet includes a mixture of proteins from these food groups each day. It is not necessary to ensure protein complementation at each meal as long as the diet includes a variety of protein sources over the course of the day (see table 1 for vegetarian sources of protein).

There is no evidence that a diet consisting of more than 1 g.kg-1.day-1 is beneficial to increase strength, power or endurance. However, excess protein in the diet can have negative health effects, such as kidney problems, dehydration, osteoporosis and renal complications. A diet consisting of too much protein is normally also too high in fat, and can contribute to the development of obesity and cardiovascular disease. Protein supplementation is not only unnecessary, but can also be unhealthy. This is true for both vegetarian and non vegetarian athletes.

Fat

Diets high in fat are not only undesirable for health reasons, but also for athletic performance. Low fat diets are more effective than high fat diets for optimal athletic performance. A landmark study by Bergstršm et al. investigated the relationship between exercise endurance and diet. The subjects rode on a bicycle ergometer, and the study found that riders that had consumed a high carbohydrate low fat diet lasted almost three times as long (167 minutes) as riders that had eaten a high fat, high protein diet (57 minutes) (3).

There is no RDA for fat, but the American Heart Association recommends that no more than 30% of the daily allowance of calories come from fat, with less than 10% from saturated fats. Other nutritional and medical authorities suggest a lower intake of fat: 15-20% of the daily calories (5).

Vegetarian diets are normally lower in fat than diets that contain meat and poultry, with vegan diets being the lowest since they don't include dairy products or eggs. However, vegetarian athletes should monitor their fat intake and ensure that they are not consuming too much fat.

Vitamins and Minerals

Certain vitamins and minerals are needed for muscular contraction, the metabolism of nutrients, transport of oxygen to the muscles, and in the oxidative reaction in the muscles. The RDA for vitamins and minerals has been set a level that encompasses a wide margin of safety. A vitamin or mineral deficiency can have a negative affect on physical performance, as well as causing various health problems. However, there is no conclusive evidence that increased intake of certain vitamins and minerals enhances performance (1).

The need for certain vitamins is increased with a higher caloric need. This applies to vegetarian as well as non-vegetarian athletes, since athletes in general need more calories each day. Riboflavin, thiamine and niacin requirements are based on total caloric intake. However, vegetarian athletes need not rely on supplements for this increased vitamin requirement. As long as their food sources include a variety of grains, fruits, vegetables and legumes the increased caloric intake will provide the increase in these vitamins (see table 1).

Vegetarians that eat a well balanced diet should have no problem fulfilling the RDA for vitamins, with the possible exception of vegans fulfilling their vitamin B-12 requirement. It may be a challenge to get enough of this vitamin from plant sources, so it is recommended by the American Dietetic Association that vegans take a B-12 supplement, or ensure that they eat several servings each week of a fortified food product (i.e. cereal or nutritional yeast, see table 1) (2).

Vitamin D is obtained naturally from sunshine, but vegetarians that live in northern climates may need a supplement. Most cow milk is fortified with vitamin D, but if dairy products are not consumed and sunshine is not readily available, a fortified food product or supplement should be taken.

The two minerals that vegetarian athletes need to pay special attention to are iron and calcium. A well balanced vegetarian diet should meet the RDA for both iron and calcium, but vegans especially may have to monitor their calcium intake to ensure adequate daily intake.

Iron is a mineral that is crucial to any athlete and his or her performance because it aids in the transport of oxygen in the blood. Anemia decreases athletic performance. The RDA for iron is 18 mg for women (it has been proposed to be lowered to 15 mg), and 10 mg for men. Iron is more easily absorbed if it is consumed with a food rich in vitamin C. (See table 1 for vegetarian food sources of iron).

The RDA for calcium, 800 mg.day-1, can easily be met by lacto vegetarians through the consumption of dairy products. However, vegans may need to pay closer attention to their intake of this mineral. (See table 1 for good vegetarian food sources of calcium).

Female athletes suffering from amenorrhea have an increased risk of developing osteoporosis later in life. Consequently they need to carefully monitor their calcium intake, and they may need more than the RDA of calcium, as much as 1,000-1,500 mg.day-1.

Calcium deficiency is rarely found in vegetarians (2). Low intake of calcium among vegetarians has not produced major health problems in this population. One reason may be that vegetarians absorb and retain more calcium from foods that they eat. Also, epidemiological studies have shown that there is a lower incidence of osteoporosis among vegetarians, despite their lower intake of calcium. This may be due to their lower intake of protein from animal sources, or in the case of vegans the absence of animal proteins in the diet (2, 5).

Hydration

All athletes should avoid dehydration. Water transports nutrients from the liver to the muscle cells, and thus dehydration can hamper performance, in addition to causing health problems. Water also helps control body temperature, and during exercise large amounts of water is lost through perspiration. It is crucial to both performance and health that water loss be replaced. Athletes should drink before, during and after prolonged exercise.

Fiber

Fiber is only found in plant foods, there is no fiber in meat, poultry, fish, seafood, eggs or dairy products. Vegetarian diets are generally high in fiber, both soluble and insoluble. This is excellent for health reasons, but may present a problem for maximum performance. Gastro intestinal problems leading to intestinal cramps, stomach cramps and diarrhea can be avoided by including only a small amount of soluble fiber in pre competition or pre exercise meals. Vegetarian athletes that have a high caloric intake need not be overly worried about getting enough fiber in the diet. The recommended daily amount of fiber is 28-35 grams, and this amount is easily met by vegetarian athletes on a high calorie diet.

Enhancing Performance

There is no scientific evidence supporting the general statement that a vegetarian diet may help performance in certain physical activities. However, research has shown that diets high in carbohydrates, low in fat and adequate in protein are advantageous in endurance events as well as body building events. A well balanced, low fat vegetarian diet has not been shown to be a detriment to athletic performance. On the contrary it may be easier for the vegetarian athlete to eat a high complex carbohydrate (65-70% of daily calories), low fat (15-25% of daily calories) and adequate protein (10-15% of daily calories) diet on a regular basis. Although no major research has focused on the attributes of vegetarian diets and performance, the high carbohydrate diet has been researched and recommended by many experts in the field of sports nutrition.

Summary

Vegetarian athletes are no different from their counterpart non-vegetarians in their daily requirements for energy and nutrients. However, some vegetarian athletes may have a more difficult time fulfilling some of these requirements. Vegetarian athletes who are not knowledgeable about nutrition should seek the advice of a registered dietician that is open minded about the vegetarian lifestyle.

Although many top level athletes in a variety of endurance and strength activities are vegetarian, the vegetarian diet per say has not been the focus of research in athletic performance. However, a low fat vegetarian diet is high in complex carbohydrates, and such a diet has been studied and recommended for maximal performance and endurance. There is no evidence to suggest that the vegetarian diet is a detriment to any sport or physical activity.

References

1. American Dietetics Association. Position of the American Dietetics Association: Nutrition for physical fitness and athletic performance for adults. J. The Am. Dietetics Assoc, 88: 352-355,1987.

2. American Dietetics Association. Position of the American Dietetics Association: Vegetarian Diets - technical support paper. J. The Am. Dietetics Assoc,, 87, 933-939, 1988.

3. Bergstršm, J., L. Hermansen, , E. Hultman, , and B. Saltin, . Diet, muscle glycogen and physical performance. Acta Physiol. Scand., 128 (suppl. 556), 67-74, 1967.

4. Costill, D. L. Carbohydrates for exercise: Dietary demands for Optimal performance. Int. J. Sports Med. 9: 1-18, 1988.

5. Robbins, J. (1990) Diet For a New America

6. Diamond, M. The American Vegetarian Cookbook, from the Fit for Life Kitchen New York: Warner Books, 1990

TABLE 1

Good, mostly low fat, vegan sources of important nutrients (usually obtained from animal sources in non-vegetarians).

ProteinUS RDA: 0.8 g.kg-1.day-1 (athletes up to 1.0 g.kg-1.day-1)

Legumes:

dried beans,

dried lentils,

split peas,

fresh lima

beans, fresh

broadbeans

Tofu

Grains:

quinoa,

amaranth,

whole wheat,

oats,

buckwheat

Vegetables:

broccoli,

cauliflower,

asparagus,

cabbage,

deep greens

CALCIUM US RDA: 800 mg

sesame seeds, broccoli, turnip greens,

dried figs, watercress, blackstrap molasses,

dried bananas and apples, grains, fortified soy milk

IRONUS RDA: females 18 mg, males 10 mg

Wheat bran, wheat germ,

rice bran,lima beans, pinto beans, lentils,

split peas, white beans, soybeans, tofu, soy milk,

dried figs, raisins, prunes,blackstrap molasses, whole grain such as

wheat, quinoa, amaranth, millet, rye.

ZINCUS RDA: 15 mg

Wheat germ, wheat bran, sesame seeds, sunflower seeds, tofu, spinach, green peas, split peas, lentils, lima beans, cornmeal, peanut butter.

Vitamin B-12: CobalaminUS RDA: 3 mcg

Nutritional yeast grown on B-12 enriched medium,

fortified cereals, supplements.

(Other vegetarian sources have been named and include a variety of fruits, sprouts and herbs (6), but the American Dietetics Association states that there is no vitamin B-12 in anything that grows out from the soil.)

Vitamin B-1: ThiamineUS RDA: 1.0-1.6 mg

Whole grains, especially brown rice, millet, wheat, rye

Legumes, especially soybeans, pintobeans, red and white beans, peas.

Sunflower seeds, sesame seeds.

Vitamin B-2: RiboflavinUS RDA: 1.2-1.7 mg

Wheat germ, wild rice, mushrooms, hot red peppers, dried banana, prunes, legumes, whole grains, broccoli, okra, sesame seeds, sunflower seeds.