Download Vegetarian diet for exercise, athletic training and

Sport nutrition
Vegetarian diet for exercise,
athletic training and performing
HEIDI M. AARSBY,
D. ENETTE LARSON-MEYER*
*Corresponding author
Department of Family and
Consumer Sciences
Dept 3354
1000 E University Ave
Laramie, WY 82071, USA
INTRODUCTION
Anno 17 - No. 2 n March/April 2006
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An apparently increasing number of
athletes are adopting vegetarian diets
for health, ethical (animal rights),
ecological, environmental and religious
or spiritual reasons. Some coaches and
professionals, however, commonly
express concern that vegetarian
athletes may not receive the proper
nutrition required for optimal training
and performance. In truth, vegetarian
athletes -from recreational to elite-can
meet their energy and nutrient
requirements on the various types of
vegetarian diets (Table 1). Like most
athletes, vegetarian athletes may
benefit from education about food
choices to optimize their health and
ABSTRACT
Optimal athletic performance requires
optimal nutrition. It has been a concern
for some coaches and professionals that
vegetarian athletes may not receive the
proper nutrition required for optimal
performance. However, if these athletes
are educated on proper nutrition, their
energy, carbohydrate, protein and fat
needs can easily be met. Vegetarians
must also make sure they ingest
adequate amounts of nutrients that are
found less abundantly in vegetarian foods
or are less well absorbed from vegetarian
compared to omnivorous diet. These
nutrients include: calcium, iron, zinc,
iodine, vitamin D, vitamin B-12, and
riboflavin. Those working with vegetarian
athletes should understand the athletes'
reasons for being vegetarian and properly
educate them on nutrient sources that fit
their personal beliefs and values.
peak performance.
This article will discuss the energy and
macronutrient needs of athletes and
active individuals, address the specific
vitamins and minerals that may be
lacking in a poorly selected vegetarian
diet, and review the nutrition
recommendations for before, during,
and after exercise. Lastly, a few tips for
professionals to consider when working
with vegetarian athletes are addressed.
ENERGY AND
MACRONUTRIENTS
athletes' diet and should make up the
bulk of their energy intakes (3).
Carbohydrate ingestion is essential for
optimal performance during prolonged
exercise periods, including extended
stop-and-go activities (4-13).
Carbohydrates are also necessary for
glycogen repletion following exercise (3,
14, 15). The amount of carbohydrates
athletes and active vegetarians need to
ingest varies, depending on sport,
intensity, gender, and body weight.
Based on research findings in mostly
male populations, it is currently
recommended that athletes ingest 6 to
10 grams of carbohydrate for every
kilogram of body mass (g/kg/day) (3).
For example, an athlete that exercises
at a high intensity for longer periods of
time would need to ingest more
carbohydrates than an athlete who did
high-intensity exercises for a shorter
amount of time. Vegetarian athletes, like
all athletes, should be educated on
proper types of carbohydrates to eat
surrounding an exercise session (Table
2 and Table 3).
Energy requirements of athletes are
variable due to the large array of sports,
activities and intensities at which
athletes can exercise. Other influencing
factors include age, gender, and body
composition. There is some concern
that vegetarian, especially vegan,
athletes may not meet their energy
needs due to the high-fiber and lowenergy density of plant-based diets (1).
Therefore, athletes with high energy
needs should
strive to consume
regular meals and
snacks that include
some low-bulk,
high-density foods
in order to ensure
adequate intake.
Vegetarians can
Table 1. Types of vegetarian diets
easily accomplish
adequate intake by
consuming: fruit
juice rather than
whole fruit and
about one-third to
one-half of their
breads, cereals,
and grains as more
refined sources,
such as white rice
or sourdough
bread rather than
whole wheat rice or
bread (1, 2).
Carbohydrates are
an important
Table 2. Suggested nutrient and fluid intake before, during, and after exercise
component of the
Vegetarian athletes are capable of
reaching their needed energy and
nutrient intakes with planning (16). The
March/April 2006 n Anno 17 - No. 2
Vitamins and minerals are an essential
part to any person's diet. Vegetarian
athletes may need to pay particular
attention to a handful
of nutrients which are
either found less
abundantly in
vegetarian foods or
are less well
absorbed from
vegetarian compared
to omnivorous diet.
These nutrients
include calcium, iron,
zinc, iodine, vitamin
D, and some of the
B-vitamins (B-12 and
Table 4. Approximate protein content of selected vegetarian food
riboflavin). Other
sources
nutrients including
potassium, magnesium, folate, vitamins
Unlike previously thought, vegetarians
A, C, E, and K are provided abundantly
do not need to consume a certain
by a well balanced vegetarian diet (3,
combination of plant-based protein at
16).
each meal in order to receive all
Calcium intake is a concern for vegan
essential amino acids. More importantly,
n
VITAMINS AND MINERALS
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Protein requirements vary according to
training level and type of activity. A very
active athlete will need more protein
than a recreational exerciser that only
exercises a few days a week. The
Recommended Dietary Allowance
(RDA) in the United States is 0.8
g/kg/day. This will meet the needs of
most people who exercise at a light to
moderate intensity most days of the
week. But, athletes who train at higher
intensities will likely need more protein.
The recommendation for endurance
athletes is 1.2 to 1.4 g/kg/day and for
resistance-trained athletes, the
recommendation can be as high as 1.6
to 1.7 g/kg/day (3).
Vegetarian athletes, especially vegans,
may need more protein than their nonvegetarian counterparts because plantbased protein may be less bioavailable
than animal-based protein. Therefore,
more protein may be needed to account
for this difference. Thus, the suggested
protein intake for vegetarian athletes is
1.3 to 1.8 g/kg/day (3). Athletes can
meet needs by consuming a variety of
plant-based protein foods and ensuring
adequate energy intake. Good sources
include soy products (tofu, tempeh,
veggie burgers, soy dogs, and other
meat analogues), legumes, nuts and nut
butters, and seeds (Table 4).
athletes and vegetarians who consume
minimal dairy products. To ensure
adequate calcium intake, these athletes
need to include several servings of well
absorbable calcium-rich plant-based
sources (24-26) (Table 5). Vitamin D,
which aids in calcium absorption is also
a concern due to reduced intake of
Vitamin D fortified foods and limited sun
exposure (particularly in indoor-sport
athletes) (27). Vitamin D requirements
can be met by spending just a few
minutes outside in shorts several times
a week (if Caucasian). Taking vitamin D
in food or as supplements is wise for
dark-skinned athletes and in winter
months for all athletes (28). Vegans,
however, should be warned because
the vitamin D3 (chocalciferol) used to
fortify some products is of animal origin
(2, 16) and the vitamin D2 form
(ergocalciferol) - often referred to as the
vegetarian vitamin D - may not be as
effective at increasing vitamin D status
(2, 16, 29). Iron intake, especially for
females, can be a concern for
vegetarian athletes as well. Non-heme
iron (plant-based iron) is best absorbed
with foods that contain ascorbic acid
(i.e. citrus fruit or juice, tomatoes, and
melon) and other organic acids and is
inhibited by plant phytates,
polyphenolics, tannins in tea, cocoa and
coffee, soy and dairy protein, and foods
with high concentrations of calcium, zinc
or other divalent cations (30, 31).
Cooking with iron cookware also boosts
iron content, particularly when the foods
are slightly acidic (i.e. tomato sauce). If
iron status is a concern, athletes should
see a doctor to determine whether iron
supplementation is truly needed.
General use of iron supplements is not
recommended due to the high risk of
hemochromotosis (32). Athletes seem to
show a decreased zinc status (33),
therefore vegetarian athletes need to
consume a variety of whole grains and
legumes daily (3, 33-35). This is
particularly important because like iron,
zinc is less well absorbed in plant-based
foods and is not found as abundantly in
vegetarian sources (16, 35). Iodine is
another red flag mineral for many
vegans and vegetarians who avoid table
salt (typically fortified with iodine) or
consume plant foods grown in iodinepoor soil (36-38). Lastly, selected Bvitamins especially B-12 and riboflavin,
may be of concern to vegan and
vegetarians who limit intake of dairy
(39). The best sources of these vitamins
and minerals for vegans and
vegetarians can be found in Table 5.
SUMMARY AND PRACTICAL TIPS
Sport nutrition
Table 3. Carbohydrate sources that contain
approximately 15-20 g CHO per serving1
a wide range of protein
throughout the day should be
consumed (16, 17). Most
athletes who meet energy
needs and consume a wide
variety of protein will meet
the required protein needs.
But those athletes
participating in heavy
resistance training, which
increases protein needs
more so than energy
demands, may need to take
special care to include high
quality plant-based protein at
most meals and snacks.
Dietary fat is also an essential part of
the diet. It should make up the
remainder of the energy intake, after
carbohydrates and proteins (3). Dietary
fat is necessary in order to provide
energy and essential fatty acids, and to
aid in the absorption of fat-soluble
vitamins (3). Fat stored within active
muscle and adipocytes are used as a
substrate during prolonged exercise of
moderate intensity and during low-level
activity (18-20). Some vegetarian
athletes tend to eat high carbohydrate
diets and inadequate fat. Very low-fat
diets may not be appropriate for
athletes with a heavy training load and
may compromise triglyceride stores
within the muscle fibers (21-23). These
athletes should be informed on how to
incorporate foods high in mono- and
polyunsaturated fats into their diets.
These types of fat can be found in foods
such as avocados, nuts and seeds,
olives and olive oil, and flax and
sesame oil.
Sport nutrition
Anno 17 - No. 2 n March/April 2006
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athlete should take extra care to ingest
some of the key nutrients discussed in
order to meet their requirements. Thus,
it is the responsibility of professionals,
coaches, and trainers to understand the
athlete's reasons for being a vegetarian
(40), be sensitive to each individuals'
needs, and properly educate vegetarian
athletes on sources of both macro- and
micronutrients mentioned that fit their
personal beliefs and values. The
professionals need to make sure the
athletes are not claiming vegetarianism
in order to mask eating disorders (41,
42). Eating disorders are serious mental
illnesses that can impair health and
athletic performance. Lastly, the athletes
should never be told that they have to
eat animal products in order to obtain
adequate nutrition.
The following are a few tips to give
athletes when instructing them on
nutrition.
- Meeting energy requirements is
crucial to obtain proper nutrition and
optimal performance.
- Carbohydrates are essential for
maximizing and restoring glycogen
stores after exercise. Athletes
should consume 6 to 10 grams of
carbohydrate/kilogram body
mass/day. Carbohydrate sources
include grain products, fruits, juices,
starchy vegetables, added sugars,
and sports supplements (Table 3).
- Protein requirements vary
depending on exercise type and
intensity. The best vegetarian
sources include soy products,
legumes, tofu, nuts, and whole
grains products (Table 4).
- Dietary fat is essential for
absorption of fat-soluble vitamins
and essential fatty acids. Fats that
emphasize mono- and
polyunsaturated fats, such as nuts
and seeds, avocados, olives and
olive oil, and sesame oil, should be
included in the diet. However,
saturated fat and trans fat intake
should be limited.
- Vegetarians should make certain
they eat plenty of foods rich in
calcium, iron, zinc, iodine, riboflavin,
B-12, and Vitamin D (Table 5).
Supplementation should be
considered for restrictive diets or
low energy-density diets.
- The athlete's reasons for being a
vegetarian should be considered
and dietary recommendations
should be based on acceptable
foods, given athletes underlying
philosophies on vegetarianism.
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