AMERICAN COLLEGE
of SPORTS MEDICINE,
AMERICAN DIETETIC ASSOCIATION
DIETITIANS OF CANADA
Nutrition and Athletic
Performance
JOINT POSITION STATEMENT
ABSTRACT
It is the position of the American Dietetic Association, Dietitians ofCanada,
and the American College of Sports Medicine that physical activity, athletic
performance, and recovery from exercise are enhanced by optimal nutrition.
These organizations recommend appropriate selection of foods and fluids,
timing of intake, and supplement choices for optimal health and exercise
performance. This updated position paper couples a rigorous, systematic,
evidence-based analysis of nutrition and performance-specific literature with
current scientific data related to energy needs, assessment of body
composition, strategies for weight change, nutrient and fluid needs, special
nutrient needs during training and competition, the use of supplements and
ergogenic aids, nutrition recommendations for vegetarian athletes, and the
roles and responsibilities of the sports dietitian. Energy and macronutrient
needs, especially carbohydrate and protein, must be met during times of high
physical activity to maintain body weight, replenish glycogen stores, and
provide adequate protein to build and repair tissue. Fat intake should be
sufficient to provide the essential fatty acids and fat-soluble vitamins and to.
contribute energy for weight maintenance. Although exercise performance
can be affected by body weight and composition, these physical measures
should not be a criterion for sports performance and daily weigh-ins are
discouraged. Adequate food and fluid should be consumed before, during,
and after exercise to help maintain blood glucose concentration during
exercise, maximize exercise performance, and improve recovery time. Athletes
should be well hydrated before exercise and drink enough fluid during and
after exercise to balance fluid losses. Sports beverages containing carbohydrates
and electrolytes may be consumed before, during, and after exercise to
help maintain blood glucose concentration, provide fuel for muscles, and
decrease risk of dehydration and hyponatremia. Vitamin and mineral supplements
are not needed if adequate energy to maintain body weight is consumed
from a variety of foods. However, athletes who restrict energy intake, use
severe weight-loss practices, eliminate one or more food groups from their
diet, or consume unbalanced diets with low micronutrient density may require
supplements. Because regulations specific to nutritional ergogenic aids are
poorly enforced, they should be used with caution and only after careful
product evaluation for safety, efficacy, potency, and legality. A qualified sports
dietitian and, in particular, the Board Certified Specialist in Sports Dietetics in
This joint position statement is authored by the American Dietetic
Association (ADA), Dietitians of Canada (DC), and American College of
Sports Medicine (ACSM). The content appears in ADA style. This paper is
being published concurrently in Medicine & Science in Sports & Exercise®
and in the Journalofthe Aminerican DieteticAssociation, and the Canadian
Journal of Dietetic Practiceand Research. Individual name recognition is
reflected in the acknowledgments at the end of the statement.
0195-9131/09/4103-0709/0
MEDICINE & SCIENCE IN SPORTS & EXERCISE®
Copyright © 2009 by the American College of Sports Medicine, American
Dietetic Association, and Dietitians of Canada.
DOI: 10.1249/MSS.0b013e318190eb86
the United States, should provide individualized nutrition direction and advice
after a comprehensive nutrition assessment.
POSITION STATEMENT
It is the position of the American Dietetic Association,
Dietitians of Canada, and the American College of Sports
Medicine that physical activity, athletic performance, and
recoveryfi-om exercise are enhanced by optimal nutrition.
These organizations recommend appropriate selection of
.food and.fluids, timing of intake, and supplement choices
for optimal health and exercisepetjbrnance.
This ADA position paper uses ADA's Evidence Analysis
Process and information from the ADA Evidence Analysis
Library (EAL). Similar information is also available from
DC's Practice-based Evidence in Nutrition (PEN). The use
of an evidence-based approach provides important added
benefits to earlier review methods. The major advantage of
the approach is the more rigorous standardization of review
criteria, which minimizes the likelihood of reviewer bias
and increases the ease with which disparate articles may be
compared. For a detailed description of the methods used in
the evidence analysis process, access the ADA's Evidence
Analysis Process at http://adaeal.com/eaprocess/.
Conclusion Statements are assigned a grade by an expert
work group based on the systematic analysis and evaluation
of the supporting research evidence: grade I = good, grade
II = fair, grade III = limited, grade IV = expert opinion only,
and grade V = a grade is not assignable because there is no
evidence to support or refute the conclusion.
Evidence-based infon-nation for this and other topics
can be found at www.adaevidencelibrary.com and www.
dieteticsatwork.com/pen and subscriptions for non-ADA
members are purchasable at https://www.adaevidencelibrary.
com/store.cfi-n. Subscriptions for DC and non-DC members
are available for PEN at http://www.dieteticsatwork.com/
pen_order.asp
KEY POINTS
The following key points summarize the current energy,
nutrient, and fluid recommendations for active adults and
competitive athletes. These general recommendations can
be adjusted by sports nutrition experts to accommodate the
709
unique concerns of individual athletes regarding health,
sports, nutrient needs, food preferences, and body weight
and body composition goals.
"*Athletes need to consume adequate energy during
periods of high-intensity and/or long-duration training
to maintain body weight and health and maximize
training effects. Low energy intakes can result in loss
ofmuscle mass; menstrual dysfunction; loss of or failure
to gain bone density; an increased risk of fatigue, injury,
and illness; and a prolonged recovery process.
"*Body weight and composition should not be used as
the sole criterion for participation in sports; daily
weigh-ins are discouraged. Optimal body fat levels
depend on the sex, age, and heredity of the athlete and
may be sport-specific. Body fat assessment techniques
have inherent variability and limitations. Preferably,
weight loss (fat loss) should take place during the offseason
or begin before the competitive season and
involve a qualified sports dietitian.
"*Carbohydrate recommendations for athletes range from
6 to 10 g.kg-1 body weight.d-1 (2.7-4.5 g-lb-1 body
weight'd-1). Carbohydrates maintain blood glucose
levels during exercise and replace muscle glycogen.
The amount required depends on the athlete's total
daily energy expenditure, type of sport, sex, and environmental
conditions.
"*Protein recommendations for endurance and strengthtrained
athletes range from 1.2 to 1.7 g-kg-' body
weight'd-1 (0.5-0.8 g'lb-1 body weight-d-1). These
recommended protein intakes can generally be met
through diet alone, without the use of protein or amino
acid supplements. Energy intake sufficient to maintain
body weight is necessary for optimal protein use and
performance.
"*Fat intake should range from 20% to 35% of total
energy intake. Consuming <20% of energy from fat
does not benefit performance. Fat, which is a source of
energy, fat-soluble vitamins, and essential fatty acids,
is important in the diets of athletes. High-fat diets are
not recommended for athletes.
"*Athletes who restrict energy intake or use severe
weight-loss practices, eliminate one or more food
groups from their diet, or consume high- or lowcarbohydrate
diets of low micronutrient density
are at greatest risk of micronutrient deficiencies.
Athletes should consume diets that provide at least
the recommended dietary allowance (RDA) for all
micronutrients.
* Dehydration (water d6ficit in excess of 2-3% body
mass) decreases exercise performance; thus, adequate
fluid intake before, during, and after exercise is
important for health and optimal performance. The
goal of drinking is to prevent dehydration from
occurring during exercise and individuals should not
drink in excess of sweating rate. After exercise,
approximately 16-24 oz (450-675 mL) of fluid for
every pound (0.5 kg) of body weight lost during
exercise.
"* Before exercise, a meal or snack should provide
sufficient fluid to maintain hydration, be relatively
low in. fat and fiber to facilitate gastric emptying and
minimize gastrointestinal distress, be relatively high
in carbohydrate to maximize maintenance of blood
glucose, be moderate in protein, be composed of
familiar foods, and be well tolerated by the athlete.
"* During exercise, primary goals for nutrient consumption
are to replace fluid losses and provide carbohydrates
(approximately 30-60 g'h-1) for maintenance of
blood glucose levels. These nutrition guidelines are
especially important for endurance events lasting
longer than an hour when the athlete has not consumed
adequate food or fluid before exercise or when the
athlete is exercising in an extreme environment (heat,
cold, or high altitude).
"* After exercise, dietary goals are to provide adequate
fluids, electrolytes, energy, and carbohydrates to replace
muscle glycogen and ensure rapid recovery. A
carbohydrate intake of approximately 1.0-1.5 g.kg-I
body weight (0.5-0.7 g.lb-1) during the first 30 min
and again every 2 h for 4-6 h will be adequate to replace
glycogen stores. Protein consumed after exercise
will provide amino acids for building and repair of
muscle tissue.
"* In general, no vitamin and mineral supplements are
required if an athlete is consuming adequate energy
from a variety of foods to maintain body weight.
Supplementation recommendations unrelated to exercise,
such as folic acid for women of childbearing
potential, should be followed. A multivitamin/mineral
supplement may be appropriate if an athlete is dieting,
habitually eliminating foods or food groups, is ill or
recovering from injury, or has a specific micronutrient
deficiency. Single-nutrient supplements may be appropriate
for a specific medical or nutritional reason (e.g.,
iron supplements to correct iron deficiency anemia).
"* Athletes should be counseled regarding the appropriate
use of ergogenic aids. Such products should only be
used after careful evaluation for safety, efficacy,
potency, and legality.
"* Vegetarian athletes may be at risk for low intakes of
energy, protein, fat, and key micronutrients such as
iron, calcium, vitamin D, riboflavin, zinc, and vitamin
B12. Consultation with a sports dietitian is recommended
to avoid these nutrition problems.
EVIDENCE-BASED ANALYSIS
Studies used in the development of this position paper
were identified from the PubMed database maintained by
the National Library of Medicine and CENTRAL database,
710 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
as well as through research articles and literature reviews.
Five topic-specific questions were identified for evidencebased
analysis (Fig. 1) and incorporated into this position,
updating the prior position on nutrition and performance
(1). Search tenrs used were athlete, performance, power,
strength, endurance, or competition and macronutrient,
meal, carbohydrate, fat, protein, or energy. For the purpose
of this analysis, inclusion criteria were adults aged 18-
40 yr; all sport settings; and trained athletes, athletes in
training, or individuals regularly exercising. Because the
grading system used provides allowances for consideration
of study design, the evidence-based analysis was not limited
to randomized controlled trials. Study design preferences
were randomized controlled trials or clinical controlled
studies; large nonrandomized observational studies; and
cohort, case-control studies. All sample sizes were included
and study dropout rate could not exceed 20%. The
publication range for the evidence-based analysis spanned
1995-2006. If an author was included in more than one
review article or primary research articles that were similar
in content, the most recent paper was accepted, and earlier
versions were rejected. However, when an author was
included in more than one review article or primary
research article for which content differed, then both
reviews could be accepted for analysis.
The following exclusion criteria were applied to all
identified studies:
"aAdults older than 40 yr, adults younger than 18 yr,
infants, children, and adolescents
"* Settings not related to sports
"* Nonathletes
"* Critical illness and other diseases and conditions
"* Drop out rates >20%
Topic Question
Energy balance and
body composition
Training
Competition
Recovery
What is the relationship between energy balance/
imbalance, body composition, and/or weight
management and athletic performance?
What is the evidence to support a particular meal
timing, caloric intake, and macronutrient intake for
optimal athletic performance during training?
What is the evidence to support a particular meal
timing, caloric intake, and macronutrient intake
for optimal athletic performance during
competition during the 24 hours prior to
competition?
What is the evidence to support a particular meal
timing, caloric intake, and macronutrient intake
for optimal athletic performance during
competition?
What is the evidence to support a particular meal
timing, caloric intake, and macronutrient intake for
optimal athletic performance during recovery?
FIGURE I-Specific topics and the respective questions used for the
evidence analysis sections of the nutrition and athletic performance
project.
"* Publication before 1995
"* Studies by same author, which were similar in content
"* Articles not in English
Conclusion statements were formulated summarizing the
strength of evidence with respect to each question (Fig. 1).
The strength of the evidence was graded using the
following elements: quality, consistency across studies,
quantity, and generalizability. A more detailed description
of the methodology used for this evidence-based analysis
may be found on the American Dietetic Association's Web
site at www.eatright.org/cps/rde/xchg/ada/hs.xsl/
8099 ENU_HTML.htm.
ENERGY METABOLISM
Energy expenditure must equal energy intake to achieve
energy balance. The energy systems used during exercise
for muscular work include the phosphagen and glycolytic
(both anaerobic) and the oxidative (aerobic) pathways. The
phosphagen system is used for events lasting no longer than
a few seconds and of high intensity. Adenosine triphosphate
(ATP) and creatine phosphate provide the readily available
energy present within the muscle. The amount of ATP
present in the skeletal muscles (-5 mmol.kg- t
wet weight)
is not sufficient to provide a continuous supply of energy,
especially at high exercise intensities. Creatine phosphate is
an ATP reserve in muscle that can be readily converted to
sustain activity for -3-5 min (2). The amount of creatine
phosphate available in skeletal muscle is approximately four
times greater than ATP and, therefore, is the primary fuel
used for high-intensity, short-duration activities such as the
clean and jerk in weight lifting or the fast break in
basketball.
The anaerobic glycolytic pathway uses muscle glycogen
and glucose that are rapidly metabolized anaerobically
through the glycolytic cascade. This pathway supports
events lasting 60-180 s. Approximately 251/6-35% of total
muscle glycogen stores are used during a single 30-s sprint
or resistance exercise bout. Neither the phosphagen nor the
glycolytic pathway can sustain the rapid provision of
energy to allow muscles to contract at a very high rate for
events lasting greater than -2-3 min.
The oxidative pathway fuels events lasting longer than
2-3 min. The major substrates include muscle and liver
glycogen, intramuscular, blood, and adipose tissue triglycerides
and negligible amounts of amino acids from muscle,
blood, liver, and the gut. Examples of events for which the
major fuel pathway is the oxidative pathway include a 1500m
run, marathon, half-marathon, and endurance cycling or
>1500-m swimming events. As oxygen becomes more
available to the working muscle, the body uses more of the
aerobic (oxidative) pathways and less of the anaerobic
(phosphagen and glycolytic) pathways. Only the aerobic
pathway can produce much ATP over time via the Krebs
cycle and the electron transport system. The greater
Medicine & Science in Sports & Exercise® 711NUTRITION AND ATHLETIC PERFORMANCE
dependence on aerobic pathways does not occur abruptly,
nor is one pathway ever relied on exclusively. The intensity,
duration, frequency, type of activity, sex, and fitness level of
the individual, as well as prior nutrient intake and energy
stores, detennine when the crossover from primarily aerobic
to anaerobic pathways occurs (2).
Conversion of energy sources over time. Approximately
50%-60% of energy during 1-4 h of continuous
exercise at 70% of maximal oxygen capacity is derived
from carbohydrates and the rest from free fatty acid
oxidation (3). A greater proportion of energy comes from
oxidation of free fatty acids, primarily those from muscle
triglycerides as the intensity of the exercise decreases (3).
Training does not alter the total amount of energy expended
but rather the proportion of energy derived from carbohydrates
and fat (3). As a result of aerobic training,
the energy derived from fat increases and from carbohydrates
decreases. A trained individual uses a greater
percentage of fat than an untrained person does at the same
workload (2). Long-chain fatty aids derived from stored
muscle triglycerides are the preferred fuel for aerobic
exercise for individuals involved in mild- to moderateintensity
exercise (4).
ENERGY REQUIREMENTS
Meeting energy needs is a nutrition priority for athletes.
Optimum athletic performance is promoted by adequate
energy intake. This section will provide information
necessary to determine energy balance for an individual.
Energy balance occurs when energy intake (the sum of
energy from foods, fluids, and supplement products) equals
energy expenditure or the sum of energy expended as basal
metabolic rate (BMR), the thermic effect of food, the
thermic effect of activity (TEA), which is the energy
expended in planned physical activity, and nonexercise
activity thennogenesis (5). Spontaneous physical activity is
also included in the TEA.
Athletes need to consume enough energy to maintain
appropriate weight and body composition while training for
a sport (6). Although usual energy intakes for many intensely
training female athletes might match those of male
athletes per kilogram body weight, some female athletes
may consume less energy than they expend. Low energy
intake (e.g., <1800-2000 kcal-d-1) for female athletes is a
major nutritional concern because a persistent state of
negative energy balance can lead to weight loss and
disruption of endocrine function (7-10).
Inadequate energy intake relative to energy expenditure
compromises performance and negates the benefits of
training. With limited energy intake, fat and lean tissue
will be used for fuel by the body. Loss of lean tissue mass
results in the loss of strength and endurance, as well as
compromised immune, endocrine, and musculoskeletal
function (11). In addition, long-tenn low energy intake
results in poor nutrient intake, particularly of the micronutrients,
and may result in metabolic dysfunctions associated
with nutrient deficiencies as well as lowered resting
metabolic rate (RMR). The newer concept of energy
availability, defined as dietary intake minus exercise energy
expenditure normalized to fat-free mass (FFM), is the
amount of energy available to the body to perform all other
functions after exercise training expenditure is subtracted.
Many researchers have suggested that 30 kcal'kg-1
FFM-d-1 might be the lower threshold of energy availability
for females (12-15).
Estimation of energy needs of athletes and active individuals
can be done using a variety ofmethods. The Dietary
Reference Intakes (DRI) (15,17) and the Dietary Guidelines
2005 (16) (http://www.health.gov/dietaryguidelines/
dga2005/report/HTML/D3 Disccalories.htm) provide energy
recommendations for men and women who are slightly
to very active, which are based on predictive equations
developed using the doubly labeled water technique
that can also be used to estimate energy needs of athletes
(Fig. 2).
Energy expenditure for different types of exercise is
dependent on the duration, frequency, and intensity of the
exercise, the sex of the athlete, and prior nutritional status.
Heredity, age, body size, and FFM also influence energy
expenditure. The more energy used in activity, the more
calories needed to achieve energy balance.
Typical laboratory facilities are usually not equipped to
determine total energy expenditure. Therefore, predictive
equations are often used to estimate BMR or RMR. The two
prediction equations considered to most closely estimate
energy expenditure are the Cunningham equation (1980)
(18) and the Harris-Benedict equation (19). Because the
Cunningham equation requires that lean body mass be
known, sports dietitians typically use the Harris-Benedict
equation. To estimate total energy expenditure, BMR or
RMR is then multiplied by the appropriate activity factor of
1.8-2.3 (representing moderate to very heavy physical activity
levels, respectively). Numeric guidelines such as these
(8) only provide an approximation of the average energy
needs of an individual athlete. An alternative method
for estimating exercise energy expenditure is to use metabolic
equivalents (METs) recorded during a 24-h period
(20). Any of these methods can be used to estimate energy
expenditure for the determination of energy intake
requirements and provide the sports dietitian with a basis to
guide the athletes or active individuals in meeting their
energy needs.
BODY COMPOSITION
Body composition and body weight are two of the many
factors that contribute to optimal exercise performance.
Taken together, these two factors may affect an athlete's
potential for success for a given sport. Body weight can
influence an athlete's speed, endurance, and power, whereas
body composition can affect an athlete's strength, agility,
712 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
The DRI method for estimating energy requirements of an adult male=
662 - 9.53(age, yrs) + PA [15.91 (weight in kg) + 539.6(height in meters)].
For an adult female estimated energy requirements =
354 - 6.91 (age, yrs) + PA [9.36 (weight in kg) + 726(height in meters)]
Physical activity (PA) is defined below.
1.0-1.39 Sedentary. typical daily living activities (e.g.. household tasks, walking to bus)
1.4-1.59 Low active, typical daily living activities plus 30-60 min of daily moderate
activity (e.g., walking at 5-7 kminh)
1.6-1.89 Active, typical daily living activities plus 60 min of daily moderate activity
1.9-2.5 Very active, typical daily activities plus a( hIast 60 min of daily moderate activity
plus an additional 60 min ofvigorous activity or 120 min ofmoderate activity.
FIGURE 2-The Dietary Reference Intake (DRI) method for estimating
energy requirement for adults (17).
and appearance. A lean body, i.e., one with greater muscle/
fat ratio, is often advantageous in sports where speed is
involved.
Athletic performance cannot be accurately predicted
based solely on body weight and composition given that
many factors affect body composition (21). Some sports
dictate that athletes make changes in body weight and
composition that may not be best for the individual athlete.
Athletes who participate in weight-class sports-such as
wrestling or lightweight rowing-may be required to lose or
gain weight to qualify for a specific weight category.
Athletes who participate in body-conscious sports, such as
dance, gymnastics, figure skating, or diving, may be pressured
to lose weight and body fat to have a lean physique,
although their current weight for health and performance is
appropriate. With extreme energy restrictions, losses of both
muscle and fat mass may adversely influence an athlete's
performance.
Individualized assessment of an athlete's body composition
and body weight or body image may be advantageous
for the improvement of athletic performance. Age, sex,
genetics, and the requirements of the sport are factors that
impact the individual athlete's body composition. An optimal
competitive body weight and relative body fatness
should be determined when an athlete is healthy and
performing at his or her best.
Methodology and equipment to performn body composition
assessments must be accessible and cost-effective. Not
all of the following methods meet these criteria for the
practitioner. In addition, athletes and coaches should know
that there are errors associated with all body composition
techniques and that it is not appropriate to set a specific
body fat percentage goal for an individual athlete. Rather, a
range of target percentages of body fat values should be
recommended.
Assessment methodology. Three levels of assessment
techniques are used to assess body composition (22).
Direct assessment based on analysis of cadavers, although
not used in clinical practice, is designated as a Level I
technique. The other two technique levels are indirect assessments
(Level II) and doubly indirect assessments (Level
Ill). Hydrodensitometry, or underwater weighing, dualenergy
x-ray absorptiometry (DXA), and air displacement
plethysmography are Level 1I techniques, and skinfold
measurements and bioelectrical impedance analysis (BIA)
are Level IIl techniques. Levels 1I and III techniques are
used in practice by sports dietitians.
Underwater weighing, once considered the criterion
standard, is no longer common. DXA, originally developed
to assess bone mineral, can be used for body composition
analysis (21). Although DXA is fairly accurate, quick, and
noninvasive, the cost of and access to the instrument limits
its use in practice. Air displacement plethysmography
(BodPod; Life Measurement, Inc, Concord, CA) is also
used to determine body composition by body density (22),
and body fat percentage is calculated using the equation of
either Siri (23) or Brozek (24). Although this method
provides valid and reliable assessment of body composition,
it may underestimate body fat in adults and children
by 2%-3% (25).
Two of the most commonly used Level Ill methods are
skinfold measurements and BIA. In addition, measures of
body weight, height, wrist and girth circumferences, and
skinfold measurements are routinely used by sports dietitians
to assess body composition. Usually, seven skinfold sites are
used including abdominal, biceps, front thigh, medial calf,
subscapular, supraspinale, and triceps. The standard techniques
and definitions of each of these sites are provided by
Heymsfield et a]. (22) and Marfell-Jones et al. (26).
Prediction equations using skinfold measurements to determine
body fat content are numerous (22). Approximately
500/o-70% of the variance in body density is accounted for
by this measurement. In addition, population differences
limit the ability to interchange the prediction equations and
standardization of skinfold sites and skinfold measurement
techniques vary from investigator to investigator. Even the
skinfold caliper is a source of variability (22). Despite the
inherent problems of skinfold measurement, this technique
remains a method of choice because it is convenient and
inexpensive. The US Olympic Committee (USOC) is using
the International Society for Advances in Kinanthropometry
(ISAK) techniques (26) as efforts are underway to standardize
measures worldwide. The USOC advocates using
the sum of seven skinfolds (mm) based on ISAK landmarks,
marking skinfold sites on the body, reporting
duplicate measures, and communicating the results as a
range, rather than percentage of body fat.
BIA is based on the principle that an electrical signal is
more easily conducted through lean tissue than fat or bone
(22). Fat mass is estimated by subtracting the BIAdetermined
estimate of FFM from total body mass. Whole
body resistance to the flow of an electrical current conducted
through the body by electrodes placed on wrists and
ankles can provide fairly accurate estimates of total body
water and FFM (22). Bioelectrical impedance analysis is
dependent on several factors that can cause error in the
measurement and must be taken into account to obtain a
fairly accurate estimate. Hydration status is the most important
factor that may alter the estimated percentage body
Medicine & Science in Sports & Exercise® 713NUTRITION AND ATHLETIC PERFORMANCE
fat. The prediction accuracy of BIA is similar to skinfold
assessments, but BIA may be preferable because it does not
require the technical skill associated with skinfold measuremnents
(27). Currently, upper and lower body impedance
devices have been developed but have not been evaluated in
an athletic population.
Body composition and sports performance. Body
fat percentage of athletes varies depending on the sex of the
athlete and the sport. The estimated minimal level of body
fat compatible with health is 5% for males and 12% for
females (22); however, optimal body fat percentages for an
individual athlete may be much higher than these minimums
and should be detennined on an individual basis. The
ISAK sum of seven skinfolds indicates that the range of
values for the athletic population is 30-60 mm for males
and 40-90 mm for females (26). Body composition analysis
should not be used as a criterion for selection of athletes for
athletic teams. Weight management interventions should be
thoughtfully designed to avoid detrimental outcomnes with
specific regard for performance, as well as body composition
(i.e., loss of lean body mass). See Figure 3for practical
guidelines for weight management of athletes.
Setting and monitoring goals
a Set realistic weight and body composition goals. Ask the athlete:
What is the maximum weight that you would find acceptable?
What was the lowest weight you maintained without constant dieting?
How did you derive your goal weight?
- At what weight and body composition do you perform best'?
n Encourage less focus on the scale and more ott healthful habits such as stress
management and making good food choices.
a Monitor progress by measuring changes in exercise performance and energy level, the
prevention of injuries, normal menstrual function, and general overall well-being.
* Help athletes to develop lifestyle changes that maintain a healthful weight for
themselves-not for their sport, for their coach, for their friends, for their parents, or to
prove a point.
Suggestions for food intake
n Low-energy intakewill not sustain athletic training. Instead, decreases in energy intake
of 10% to 20% of normal intake will lead to weight loss without the athlete feeling deprived
or overly hungry. Strategies such as substituting lower-fat foods for whole-fat foods,
reducing intake ofenergy-dense snacks, portion awareness and doing activities other than
eating when not hungry can be useful.
n Ifappropriate, athletes can reduce fat intake but need to know that a lower-fat diet will
not guarantee weight loss unless a negative energy balance (reduced energy intake and
increased energy expenditure) is achieved. Fat intake should not be decreased below
15% of total energy intake, because some fat is essential for good health.
"*Emphasize increased intake of whole grains and cereals, and legumes.
"*Five or more daily servings of fruits and vegetables provide nutrients and fiber.
"*Dieting athletes should not skimp on protein and need to maintain adequate calcium
intakes. Accordingly, use of low-fat dairy products and lean meats, fish, and poultry is
suggested.
u A variety of fluids-especially water- should be consumed throughout the day, including
before, during, and after exercise. Dehydration as a means of reaching a bodyweight
goal is contraindicated.
Other weight management strategies
i Advise athletes against skipping meals (especially breakfast) and allowing themselves
to become overly hungry. They should be prepared for times when they might get
hungry, including keeping nutritious snacks available for those times.
n Athletes should not deprive themselves of favorite foods or set unrealistic dietary rules
or guidelines. Instead, dietary goals should be flexible and achievable. Athletes should
remember that all foods can fit into a healthful lifestyle. Developing list of "good" and
"bad" food is discouraged.
n Help athletes identify their own dietary weaknesses and plan strategies for dealing with
them.
a Remind athletes that they are making lifelong dietary changes to sustain a healthful
weight and optimal nutritional status rather than going on a short-term "diet".
FIGURE 3-Weight management strategies for athletes. Modified with
permission from: Manore MM. Chronic dieting in active women: what
are the health consequences? Womens Health Issues. 1996;6:332-41.
Conclusion statement. Four studies have reported
inconclusive findings related to the effects of energy and
protein restriction on athletic perfonn-ance, but carbohydrate
restriction has been shown to be detrimental. For weightclass
athletes, two studies show that weight loss preceding
athletic competition may have no significant effect on
measures of performance, depending on refeeding protocol.
(Evidence Grade III = Limited). (www.adaevidence-
library.com/conclusion.cfm?conclusion_statement_id
=250448).
MACRONUTRIENT REQUIREMENTS
FOR EXERCISE
Athletes do not need a diet substantially different from
that recommended in the Dietary Guidelines for Americans
(16) and Eating Well with Canada's Food Guide (28).
Although high-carbohydrate diets (more than 60% of
energy intake) have been advocated in the past, caution is
recommended in using specific proportions as a basis for
meal plans for athletes. For example, when energy intake is
4000-5000 kcal.d-', even a diet containing 50% of the
energy from carbohydrate will provide 500-600 g of
carbohydrate (or approximately 7-8 g'kg-1 (3.2-3.6 g-lb-")
for a 70-kg (154 lb) athlete), an amount sufficient to
maintain muscle glycogen stores from day to day (29).
Similarly, if protein intake for this plan was 10% of energy
intake, absolute protein intake (100-125 g'd-1) could
exceed the recommended protein intake for athletes (1.2-
1.7 g'kg-.'d-1 or 84-119 g in a 70-kg athlete). Conversely,
when energy intake is less than 2000 kcal'd-1, a diet
providing 60% of the energy from carbohydrate may
not be sufficient to maintain optimal carbohydrate stores
(4-5 g'kg-1 or 1.8-2.3 g-lb-1) in a 60-kg (132 lb) athlete.
Protein. Protein metabolism during and after exercise is
affected by sex, age, intensity, duration, and type of
exercise, energy intake, and carbohydrate availability. More
detailed reviews of these factors and their relationship to
protein metabolism and needs of active individuals can be
found elsewhere (30,31). The current recommended dietary
allowance (RDA) is 0.8 g'kg-1 body weight and the acceptable
macronutrient distribution range (AMDR) for
protein intake for adults older than 18 yr is I01/o-35% oftotal
calories (15). Because there is not a strong body of evidence
documenting that additional dietary protein is needed by
healthy adults who undertake endurance or resistance exercise,
the current DRI for protein and amino acids does not
specifically recognize the unique needs ofroutinely active individuals
and competitive athletes. However, recommending
protein intakes in excess of the RDA to maintain optimum
physical performance is commonly done in practice.
Endurance athletes. An increase in protein oxidation
during endurance exercise, coupled with nitrogen balance
studies, provides the basis for recommending increased
protein intakes for recovery from intense endurance training
(32). Nitrogen balance studies suggest that dietary protein
714 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
intake necessary to support nitrogen balance in endurance
athletes ranges from 1.2 to 1.4 g-kg-'d-' (29-31). These
recommendations remain unchanged, although recent studies
have shown that protein turnover may become more
efficient in response to endurance exercise training (29,32).
Ultra-endurance athletes who engage in continuous activity
for several hours or consecutive days of intermittent
exercise should also consume protein at or slightly above
1.2-1.4 g.kg 1
-d-1 (32). Energy balance, or the consumption
of adequate calories, particularly carbohydrates, to
meet those expended, is important to protein metabolism so
that amino acids are spared for protein synthesis and not
oxidized to assist in meeting energy needs (33,34). In
addition, discussion continues as to whether sex differences
in protein-related metabolic responses to exercise exist
(35,36).
Strength athletes. Resistance exercise may necessitate
protein intake in excess of the RDA, as well as that needed
for endurance exercise, because additional protein, essential
amino acids in particular, is needed along with sufficient
energy to support muscle growth (30,31). This is particularly
true in the early phase of strength training when the
most significant gains in muscle size occurs. The amount of
protein needed to maintain muscle mass may be lower for
individuals who routinely resistance train because of more
efficient protein use (30,31). Recommended protein intakes
for strength-trained athletes range from approximately 1.2
to 1.7 g.kg'-d-1 (30,32).
Protein and amino acid supplements. High-protein
diets have been popular throughout history. Although
earlier investigations in this area involved supplementation
with individual amino acids (37,38), more recent work has
shown that intact high-quality proteins such as whey,
casein, or soy are effectively used for the maintenance,
repair, and synthesis of skeletal muscle proteins in response
to training (39). Protein or amino acids consumed near
strength and endurance exercise can enhance maintenance
of, and net gains in, skeletal muscle (39,40). Because
protein or amino acid supplementation has not been shown
to positively impact athletic performance (41,42),
recommendations regarding protein supplementation are
conservative and directed primarily at optimizing the
training response to and the recovery period after exercise.
From a practical perspective, it is important to conduct a
thorough nutrition assessment specific to the athlete's goals
before recommending protein powders and amino acid
supplements to athletes.
Fat. Fat is a necessary component of a normal diet,
providing energy and essential elements of cell membranes
and associated nutrients such as vitamins A, D, and E. The
acceptable macronutrient distribution range (AMDR) for fat
is 20%-35% of energy intake (17). The Dietary Guidelines
for Americans (16) and Eating Well with Canada's Food
Guide (28) make recommendations that the proportion of
energy from fatty acids be 10% saturated, 10% polyunsaturated,
10% monounsaturated, and include sources of
essential fatty acids. Athletes should follow these general
recommendations. Careful evaluation of studies suggesting
a positive effect of consuming diets for which fat provides
>70% of energy intake on athletic performance (43,44) does
not support this concept (45).
VITAMINS AND MINERALS
Micronutrients play an important role in energy production,
hemoglobin synthesis, maintenance of bone health,
adequate immune function, and protection of body against
oxidative damage. They assist with synthesis and repair of
muscle tissue during recovery from exercise and injury.
Exercise stresses many of the metabolic pathways where
micronutrients are required, and exercise training may result
in muscle biochemical adaptations that increase micronutrient
needs. Routine exercise may also increase the turnover
and loss of these micronutrients from the body. As a result,
greater intakes of micronutrients may be required to cover
increased needs for building, repair, and maintenance of
lean body mass in athletes (46).
The most common vitamins and minerals found to be of
concern in athletes' diets are calcium and vitamin D, the B
vitamins, iron, zinc, magnesium, as well as some antioxidants
such as vitamins C and E, 0-carotene, and selenium
(46-50). Athletes at greatest risk for poor micronutrient
status are those who restrict energy intake or have severe
weight-loss practices, who eliminate one or more of the
food groups from their diet, or who consume unbalanced
and low micronutrient-dense diets. These athletes may
benefit from a daily multivitamin-and-mineral supplement.
Use of vitamin and mineral supplements does not improve
performance in individuals consuming nutritionally adequate
diets (46-48, 50).
B Vitamins:Thiamin, Riboflavin, Niacin, Vitamin B6,
Pantothenic Acid, Biotin, Folate, Vitamin B12
Adequate intake of B vitamins is important to ensure
optimum energy production and the building and repair of
muscle tissue (48,51). The B-complex vitamins have two
major functions directly related to exercise. Thiamin, riboflavin,
niacin, pyridoxine (B6), pantothenic acid, and biotin
are involved in energy production during exercise (46,51),
whereas folate and vitamin B12 are required for the production
of red blood cells, for protein synthesis, and in
tissue repair and maintenance including the CNS. Of the B
vitamins, riboflavin, pyridoxine, folate, and vitamin B12 are
frequently low in female athletes' diets, especially those
who are vegetarian or have disordered eating patterns
(47,48).
Limited research has been conducted to examine whether
exercise increases the need for the B-complex vitamins
(46,48). Some data suggest that exercise may slightly
increase the need for these vitamins as much as twice
the current recommended amount (48); however, these
Medicine & Science in Sports & Exercise® 715NUTRITION AND ATHLETIC PERFORMANCE
increased needs can generally be met with higher energy
intakes. Although short-term marginal deficiencies of B
vitamins have not been observed to impact performance,
severe deficiency of vitamin B12, folate, or both may result
in anemia and reduced endurance performance (46,47,52).
Therefore, it is important that athletes consume adequate
amounts of these micronutrients to support their efforts for
optimal performance and health.
Vitamin D
Vitamin D is required for adequate calcium absorption,
regulation of serum calcium and phosphorus levels, and
promotion of bone health. Vitamin D also regulates the
development and homeostasis of the nervous system and
skeletal muscle (53-55). Athletes who live at northern
latitudes or who train primarily indoors throughout the year,
such as gymnasts and figure skaters, are at risk for poor
vitamin D status, especially if they do not consume foods
fortified with vitamin D (50,56,57). These athletes would
benefit from supplementation with vitamin D at the DRI
level (5 /g.d-1 or 200 IU for ages 19-49 yr) (54,56,58-61).
A growing number of experts advocate that the RDA for
vitamin D is not adequate (53,62,63).
Antioxidants: Vitamins C and E, 13-Carotene, and
Selenium
The antioxidant nutrients, vitamins C and E, 0-carotene,
and selenium, play important roles in protecting cell
membranes from oxidative damage. Because exercise can
increase oxygen consumption by 10- to 15-fold, it has been
hypothesized that long-term exercise produces a constant
"oxidative stress" on the muscles and other cells (49)
leading to lipid peroxidation of membranes. Although
short-term exercise may increase levels of lipid peroxide
by-products (64), habitual exercise has been shown to result
in an augmented antioxidant system and reduced lipid
peroxidation (50,65). Thus, a well-trained athlete may have
a more developed endogenous antioxidant system than a
sedentary person. Whether exercise increases the need for
antioxidant nutrients remains controversial. There is little
evidence that antioxidant supplements enhance physical
performance (49,50,64,66). Athletes at greatest risk for poor
antioxidant intakes are those following a low-fat diet,
restricting energy intakes, or limiting dietary intakes of
fruits, vegetables, and whole grains (29,66).
The evidence that a combination ofantioxidants or single
antioxidants such as vitamin E may be helpful in reducing
inflammation and muscle soreness during recovery from
intense exercise remains unclear (42,67). Although the
ergogenic potential of vitamin E concerning physical
performance has not been clearly documented, endurance
athletes may have a higher need for this vitamin. Indeed,
vitamin E supplementation has been shown to reduce
lipid peroxidation during aerobic/endurance exercise and
have a limited effect with strength training (66). There is
some evidence that vitamin E may attenuate exerciseinduced
DNA damage and enhance recovery in certain
active individuals; however, more research is needed (66).
Athletes should be advised not to exceed the tolerable upper
intake levels (UL) for antioxidants because higher doses
could be pro-oxidative with potential negative effects
(46,64,68).
Vitamin C supplements do not seem to have an ergogenic
effect if the diet provides adequate amounts of this nutrient.
Because strenuous and prolonged exercise has been shown
to increase the need for vitamin C, physical performance
can be compromised with marginal vitamin C status or
deficiency. Athletes who participate in habitual prolonged,
strenuous exercise should consume 100-1000 mg of vitamin
C daily (47,69,70).
Minerals: Calcium, Iron, Zinc, and Magnesium
The primary minerals low in the diets of athletes, especially
female athletes, are calcium, iron, zinc, and magnesium
(47). Low intakes of these minerals are often due to
energy restriction or avoidance of animal products (70).
Calcium. Calcium is especially important for growth,
maintenance and repair of bone tissue, maintenance of
blood calcium levels, regulation of muscle contraction,
nerve conduction, and normal blood clotting. Inadequate
dietary calcium and vitamin D increase the risk of low bone
mineral density and stress fractures. Female athletes are at
greatest risk for low bone mineral density if energy intakes
are low, dairy products and other calcium-rich foods are
inadequate or eliminated from the diet, and menstrual
dysfunction is present (47,52,55,71-73).
Supplementation with calcium and vitamin D should be
determined after nutrition assessment. Current recommendations
for athletes with disordered eating, amenorrhea, and
risk for early osteoporosis are 1500 mg of elemental
calcium and 400-800 RU of vitamin D per day (50,72,73).
Iron. Iron is required for the formation of oxygencarrying
proteins, hemoglobin and myoglobin, and for
enzymes involved in energy production (50,74). Oxygencarrying
capacity is essential for endurance exercise as well
as nornnal function of the nervous, behavioral, and immune
systems (64,74). Iron depletion (low iron stores) is one of
the most prevalent nutrient deficiencies observed among
athletes, especially females (75). Iron deficiency, with or
without anemia, can impair muscle function and limit work
capacity (47,58,75,76). Iron requirements for endurance
athletes, especially distance runners, are increased by approximately
70% (58,74). Athletes who are vegetarian or
regular blood donors should aim for an iron intake greater
than their respective RDA (i.e., 18 mg and 8 mg, for men
and women respectively).
The high incidence of iron depletion among athletes is
usually attributed to inadequate energy intake. Other factors
that can impact iron status include vegetarian diets that have
716 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
poor iron availability, periods of rapid growth, training at
high altitudes, increased iron losses in sweat, feces, urine,
menstrual blood, intravascular hemolysis, foot-strike hemolysis,
regular blood donation, or injury (50,75,77). Athletes,
especially women, long-distance runners, adolescents, and
vegetarians should be screened periodically to assess and
monitor iron status (75,77,78).
Because reversing iron deficiency anemia can require
3-6 months, it is advantageous to begin nutrition intervention
before iron deficiency anemia develops (47,75).
Although depleted iron stores (low serum ferritin) are
more prevalent in female athletes, the incidence of iron
deficiency anemia in athletes is similar to that of the
nonathlete female population (50,75,77). Chronic iron
deficiency, with or without anemia, that results from
consistently poor iron intake can negatively impact health,
physical, and mental performance and warrants prompt
medical intervention and monitoring (76,78).
Some athletes may experience a transient decrease in
serum ferritin and hemoglobin at the initiation of training
due to hemodilution after an increase in plasma volume
known as "dilutional" or "sports anemia" and may not
respond to nutrition intervention. These changes seem to be
a beneficial adaptation to aerobic training, which do not
negatively impact performance (50).
In athletes who are iron-deficient, iron supplementation
not only improves blood biochemical measures and iron
status but also increases work capacity as evidenced by
increasing oxygen uptake, reducing heart rate, and decreasing
lactate concentration during exercise (47). There is
some evidence that athletes who aie iron-deficient but do
not have anemia may benefit from iron supplementation
(50,75). Recent findings provide additional support for
improved perfornance (i.e., less skeletal muscle fatigue)
when iron supplementation was prescribed as 100-mg
ferrous sulfate for 4-6 wk (76). Improving work capacity
and endurance, increasing oxygen uptake, reducing lactate
concentrations, and reducing muscle fatigue are benefits of
improved iron status (50).
Zinc. Zinc plays a role in growth, building and repair of
muscle tissue, energy production, and immune status. Diets
low in animal protein, high in fiber and vegetarian diets, in
particular, are associated with decreased zinc intake (50,52).
Zinc status has been shown to directly affect thyroid
hormone levels, BMR, and protein use, which in turn can
negatively affect health and physical performance (50).
Survey data indicate that a large number of North
Americans have zinc intakes below recommended levels
(74,75,79). Athletes, particularly females, are also at risk for
zinc deficiency (79). The impact of low zinc intakes on zinc
status is difficult to measure because clear assessment
criteria have not been established and plasma zinc concentrations
may not reflect changes in whole-body zinc status
(47,79). Decreases in cardiorespiratory function, muscle
strength, and endurance have been noted with poor zinc
status (47). The UL for zinc is 40 mg (74). Athletes should
be cautioned against single-dose zinc supplements because
they often exceed this amount, and unnecessary zinc supplementation
may lead to low HDL cholesterol and nutrient
imbalances by interfering with absorption of other nutrients
such as iron and copper (47). Further, the benefits of zinc
supplementation to physical performance have not been
established.
Magnesium. Magnesium plays a variety of roles in
cellular metabolism (glycolysis, fat, and protein metabolism)
and regulates membrane stability and neuromuscular,
cardiovascular, immune, and hormonal functions (47,55).
Magnesium deficiency impairs endurance performance by
increasing oxygen requirements to complete submaximal
exercise. Athletes in weight-class and body-conscious
sports, such as wrestling, ballet, gymnastics, and tennis,
have been reported to consume inadequate dietary magnesium.
Athletes should be educated about good food sources
of magnesium. In athletes with low magnesium status,
supplementation might be beneficial (47).
Sodium, Chloride, and Potassium
Sodium is a critical electrolyte, particularly for athletes
with high sweat losses (80-83). Many endurance athletes
will require much more than the UL for sodium (2.3 g'd-')
and chloride (3.6 g'd-1). Sports drinks containing sodium
(0.5-0.7 g'L-1) and potassium (0.8-2.0 g'L-1), as well as
carbohydrate, are recommended for athletes especially in
endurance events (>2 h) (50,80,82,83).
Potassium is important for fluid and electrolyte balance,
nerve transmission, and active transport mechanisms. During
intense exercise, plasma potassium concentrations tend to
decline to a lesser degree than sodium. A diet rich in a variety
offresh vegetables, fruits, nuts/seeds, dairy foods, lean meats,
and whole grains is usually considered adequate for maintaining
normal potassium status among athletes (32,83).
HYDRATION
Being well hydrated is an important consideration for
optimal exercise performance. Because dehydration
increases the risk of potentially life-threatening heat injury
such as heat stroke, athletes should strive for euhydration
before, during, and after exercise. Dehydration (loss of>2%
body weight) can compromise aerobic exercise performance,
particularly in hot weather, and may impair
mental/cognitive performance (83).
The American College of Sports Medicine's (ACSM)
Position Stand on exercise and fluid replacement (83)
provides a comprehensive review of the research and
recommendations for maintaining hydration before, during,
and after exercise. In addition, ACSM has published
position stands specific to special environmental conditions
(84,85). The major points from these position stands are the
basis for the following recommendations.
Medicine & Science in Sports & Exercise® 717NUTRITION AND ATHLETIC PERFORMANCE
Fluid and Electrolyte Recommendations
* Before exercise
At least 4 h before exercise, individuals should drink
approximately 5-7 mL'kg-I body weight (-2-3 miLlb-')
of water or a sport beverage. This would allow enough time
to optimize hydration status and for excretion of any excess
fluid as urine. Hyperhydration with fluids that expand
the extra- and intracellular spaces (e.g., water and glycerol
solutions) will greatly increase the risk of having to void
during competition (83) and provides no clear physiologic
or performance advantage over euhydration. This practice
should be discouraged (83).
* During exercise
Athletes dissipate heat produced during physical activity
by radiation, conduction, convection, and vaporization of
water. In hot, dry environments, evaporation accounts for
more than 80% of metabolic heat loss. Sweat rates for any
given activity will vary according to ambient temperature,
humidity, body weight, genetics, heat acclimatization state,
and metabolic efficiency. Depending on the sport and
condition, sweat rates can range from as little as 0.3 to as
much as 2.4 L.h-' (83). In addition to water, sweat also
contains substantial but variable amounts of sodium. The
average concentration of sodium in sweat approximates
50 mmol.L-1 or approximately I g.L-1 (although concentrations
vary widely). There are modest amounts of
potassium and small amounts of minerals such as
magnesium and chloride lost in sweat.
The intent of drinking during exercise is to avert a water
deficit in excess of 2% of body weight. The amount and rate
of fluid replacement is dependent on the individual athlete's
sweat rate, exercise duration, and opportunities to drink
(83). Readers are referred to the ACSM position stand for
specific recommendations related to body size, sweat rates,
types of work, etc., and are encouraged to individualize
hydration protocols when possible (83).
Consumption of beverages containing electrolytes and
carbohydrates can help sustain fluid and electrolyte balance
and endurance exercise performance (83). The type,
intensity, and duration of exercise and environmental
conditions will alter the need for fluids and electrolytes.
Fluids containing sodium and potassium help replace sweat
electrolyte losses, whereas sodium stimulates thirst and
fluid retention and carbohydrates provides energy. Beverages
containing 6%-8% carbohydrate are recommended for
exercise events lasting longer than 1 h (83).
Fluid balance during exercise is not always possible
because maximal sweat rates exceed maximal gastric
emptying rates that in turn limit fluid absorption, and most
often, rates of fluid ingestion by athletes during exercise fall
short of amounts that can be emptied fromn the stomach and
absorbed by the gut. Gastric emptying is maximized when
the amount of fluid in the stomach is high and reduced with
hypertonic fluids or when carbohydrate concentration is
greater than 8%.
Disturbances of fluid and electrolyte balance that can
occur in athletes include dehydration, hypohydration, and
hyponatremia (83). Exercise-induced dehydration develops
because of fluid losses that exceed fluid intake. Although
some individuals begin exercise euhydrated and dehydrate
over an extended duration, athletes in some sports might
start training or competing in a dehydrated state because
the interval between exercise sessions is inadequate for
full rehydration (82). Another factor that may predispose an
athlete to dehydration is "making weight" as a prerequisite
for a specific sport or event. Hypohydration, a practice of
some athletes competing in weight-class sports (i.e.,
wrestling, boxing, lightweight crew, martial arts, etc.), can
occur when athletes dehydrate themselves before beginning
a competitive event. Hypohydration can develop by fluid
restriction, certain exercise practices, diuretic use, or sauna
exposure before an event. In addition, fluid deficits may
span workouts for athletes who participate in multiple or
prolonged daily sessions of exercise in the heat (84).
Hyponatremia (serum sodium concentration less than
130 iminol.L 1) can result from prolonged, heavy sweating
with failure to replace sodium, or excessive water intake.
Hyponatremia is more likely to develop in novice marathoners
who are not lean, who run slowly, who sweat less, or who
consume excess water before, during, or after an event (83).
Skeletal muscle cramps are associated with dehydration,
electrolyte deficits, and muscle fatigue. Non-heat-acclimatized
American football players commonly experience dehydration
and muscle cramping particularly during formal preseason
practice sessions in late summer. Athletes participating in
tennis matches, long-cycling races, late-season triathlons,
soccer, and beach volleyball are also susceptible to dehydration
and muscle cramping. Muscle cramps also occur in
winter-sport athletes such as cross-country skiers and ice
hockey players. Muscle cramps are inore common in profuse
sweaters who experience large sweat sodium losses (83).
e After exercise
Because many athletes do not consume enough fluids
during exercise to balance fluid losses, they complete their
exercise session dehydrated to some extent. Given adequate
time, intake of normal meals and beverages will restore
hydration status by replacing fluids and electrolytes lost
during exercise. Rapid and complete recovery from excessive
dehydration can be accomplished by drinking at least
16-24 oz (450-675 mL) of fluid for every pound (0.5 kg) of
body weight lost during exercise. Consuming rehydration
beverages and salty foods at meals/snacks will help replace
fluid and electrolyte losses (83).
Special Environmental Conditions
Hot and humid environments. The risk for dehydration
and heat injury increases dramatically in hot, humid
718 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
environments (84). When the ambient temperature exceeds
body temperature, heat cannot be dissipated by radiation.
Moreover, the potential to dissipate heat by evaporation of
sweat is substantially reduced when the relative humidity is
high. There is a very high risk of heat illness when temperature
and humidity are both high. Ifcompetitive events occur
under these conditions, it isnecessary to take every precaution
to ensure that athletes are well hydrated, have ample access to
fluids, and are monitored for heat-related illness.
Cold environments. It is possible for dehydration to
occur in cool or cold weather (85). Factors contributing to
dehydration in cold environments include respiratory fluid
losses and sweat losses that occur when insulated clothing
is worn during intense exercise. Dehydration can also occur
because of low rates of fluid ingestion. If an athlete is
chilled and available fluids are cold, the incentive to drink
may be reduced. Finally, removal of multiple layers of
clothing to urinate may be inconvenient and difficult for
some athletes, especially women, and they may voluntarily
limit fluid intake (86).
Altitude. Fluid losses beyond those associated with
any exercise performed may occur at altitudes >2500 m
(8200 ft) consequent to mandatory diuresis and high
respiratory water losses, accompanied by decreased appetite.
Respiratory water losses may be as high as 1900
mL'd- 1
(1.9 L'd-') in men and 850 mL.d-' (0.85 L'd-') in
women (87,88). Total fluid intake at high altitude
approaches 3-4 L.d-1 to promote optimal kidney function
and maintain urine output of -1.4 L in adults (87).
THE TRAINING DIET
The fundamental differences between an athlete's diet
and that of the general population are that athletes require
additional fluid to cover sweat losses and additional energy
to fuel physical activity. As discussed earlier, it is
appropriate for much ofthe additional energy to be supplied
as carbohydrate. The proportional increase in energy
requirements seems to exceed the proportional increase in
needs for most other nutrients. Accordingly, as energy
requirements increase, athletes should first aim to consume
the maximum number of servings appropriate for their
needs from carbohydrate-based food groups (bread, cereals
and grains, legumes, milk/alternatives, vegetables, and
fruits). Energy needs for many athletes will exceed the
amount of energy (kcal.d-1) in the upper range of servings
for these food groups. Conversely, athletes who are
small and/or have lower energy needs will need to pay
greater attention to making nutrient-dense food choices
to obtain adequate carbohydrate, protein, essential fats, and
micronutrients.
With regard for the timing of meals and snacks, common
sense dictates that food and fluid intake around workouts be
determined on an individual basis with consideration for an
athlete's gastrointestinal characteristics as well as the
duration and intensity of the workout. For example, an
athlete might tolerate a snack consisting of milk and a
sandwich I h before a low-intensity workout but would be
uncomfortable if the same meal was consumed before a
very hard effort. Athletes in heavy training or doing
multiple daily workouts may need to eat more than three
meals and three snacks per day and should consider every
possible eating occasion. These athletes should consider
eating near the end of a workout, having more than one
afternoon snack, or eating a substantial snack before bed.
Conclusion statement. Twenty-three studies investigating
consumption of a range of macronutrient composition
during the training period on athletic perfonnance were
evaluated. Nine studies have reported that the consumption
of a high-carbohydrate diet (>60% of energy) during
the training period and the week before competition results
in improved muscle glycogen concentrations and/or significant
improvements in athletic performance. Two studies
reported no additional performance benefits when consuming
level above 6 g carbohydrates.kg-l body weight. Two
studies report sex differences; women may have less ability
to increase muscle glycogen concentrations through increased
carbohydrate consumption, especially when energy
intake is insufficient. One study based on the consumption
of a high-fat diet (>65% of energy) for 10 d followed by
a high-carbohydrate diet (>65% of energy) for 3 d reported
a significant improvement in athletic performance. Nine
studies report no significant effects of macronutrient composition
on athletic performance during the training period
and week before competition. (Evidence Grade II = Fair).
(www.adaevidencelibrary.com/conclusion.cfm?conclusion_
statement_id=250447).
Pre-Exercise Meal
Eating before exercise, as opposed to exercising in the
fasting state, has been shown to improve performance
(89,90). The meal or snack consumed before competition or
an intense workout should prepare athletes for the upcoming
activity and leave the individual neither hungry nor
with undigested food in the stomach. Accordingly, the following
general guidelines for meals and snacks should be
used: sufficient fluid should be ingested to maintain hydration,
foods should be relatively low in fat and fiber to
facilitate gastric emptying and minimize gastrointestinal
distress, high in carbohydrate to maintain blood glucose and
maximize glycogen stores, moderate in protein, and familiar
to the athlete.
The size and timing of the pre-exercise meal are interrelated.
Because most athletes do not like to compete on a full
stomach, smaller meals should be consumed near the event to
allow for gastric emptying, whereas larger meals can be consumed
when more time is available before exercise or competition.
Amounts of carbohydrate shown to enhance
performance have ranged from approximately 200 to 300 9
of carbohydrate for meals consumed 3-4 h before exercise.
Studies report either no effect or beneficial effects of
Medicine &Science in Sports & Exercise® 719NUTRITION AND ATHLETIC PERFORMANCE
pre-event feeding on performance (91-98). Data are equivocal
concerning whether the glycemic index of carbohydrate
in the pre-exercise meal affects performance (92,99-102).
Although the above guidelines are sound and effective,
the athlete's individual needs must be emphasized. Some
athletes consume and enjoy a substantial meal (e.g., pancakes,
juice, and scrambled eggs) 2-4 h before exercise or
competition; however, others may experience severe gastrointestinal
distress after such a meal and need to rely on
liquid meals. Athletes should always ensure that they know
what works best for themselves by experimenting with new
foods and beverages during practice sessions and planning
ahead to ensure they will have access to these foods at the
appropriate time.
Conclusion statement. Nineteen studies investigating
the consumption of a range of macronutrient composition
during the 24 h before competition on athletic performance
were evaluated. Of eight studies, six reported no significant
effect of meal consumption 90 min to 4 h before trials on
athletic performance. Six studies that focused on the
consumption of food or beverage within the hour before
competition reported no significant effects on athletic
performance, despite hyperglycemia, hyperinsulinemia,
increased carbohydrate oxidation, and reduced free fatty
acid availability. Variations in research methodology on
glycemic index ofmeals consumed before competition have
led to inconclusive findings. (Evidence Grade 11 = Fair).
(www.adaevidencelibrary.com/conclusion.cfm?conclusion
statement_id=250452).
During Exercise
Current research supports the benefit of carbohydrate
consumption in amounts typically provided in sport drinks
(6%-8%) to endurance performance in events lasting 1 h or
less (103-105), especially in athletes who exercise in the
morning after an overnight fast when liver glycogen levels
are decreased. Providing exogenous carbohydrate during
exercise helps maintain blood glucose levels and improve
performance (106).
For longer events, consuming 0.7 g carbohydrates.kg-I
body weight.h-1 (approximately 30-60 g'h-1) has been
shown unequivocally to extend endurance performance
(107,108). Consuming carbohydrates during exercise is
even more important in situations when athletes have not
carbohydrate-loaded, not consumed pre-exercise meals, or
restricted energy intake for weight loss. Carbohydrate
intake should begin shortly after the onset of activity;
consuming a given amount of carbohydrate as a bolus after
2 h of exercise is not as effective as consuming the same
amount at 15- to 20-min intervals throughout the 2 h of
activity (109). The carbohydrate consumed should yield
primarily glucose; fructose alone is not as effective and may
cause diarrhea, although mixtures of glucose and fructose,
other simple sugars and maltodextrins, seem effective (107).
If the same total amount of carbohydrate and fluid is
ingested, the form of carbohydrate does not seem to matter.
Some athletes may prefer to use a sport drink, whereas
others may prefer to consume a carbohydrate snack or
sports gel and consume water. As described elsewhere in
this document, adequate fluid intake is also essential for
maintaining endurance performance.
Conclusion statement. Thirty-six studies investigating
the consumption of a range of macronutrient composition
during competition on athletic performance were
evaluated. Seven studies based on carbohydrate consumption
during exercise lasting less than 60 min show
conflicting results on athletic performance. However, of
17 studies based on carbohydrate consumption during
exercise lasting greater than 60 min, 5 reported improved
metabolic response, and 7 of 12 studies reported improvements
in athletic performance. Evidence is inconclusive
regarding the addition of protein to carbohydrate
during exercise on athletic performance. Seven studies
based on consumption of pre-exercise meals in addition to
carbohydrate consumption during exercise suggest enhanced
athletic performance. (Evidence Grade II = Fait).
(www.adaevidencelibrary.com/conclusion.cfm?conclusion_
statement_id=250453).
Recovery
The timing and composition of the postcompetition or
postexercise meal or snack depend on the length and
intensity of the exercise session (i.e., whether glycogen
depletion occurred) and on when the next intense workout
will occur. For example, most athletes will finish a
marathon with depleted glycogen stores, whereas glycogen
depletion would be less marked after a 90-min training run.
Because athletes competing in a marathon are not likely to
perform another race or hard workout the same day, the
timing and composition of the postexercise meal is less
critical for these athletes. Conversely, a triathlete participating
in a 90-min run in the morning and a 3-h cycling
workout in the afternoon needs to maximize recovery
between training sessions. The postworkout meal assumes
considerable importance in meeting this goal.
Timing of postexercise carbohydrate intake affects
glycogen synthesis over the short term (110). Consumption
of carbohydrates within 30 min after exercise (1.0-1.5 g
carbohydrate.kg at 2-h intervals up to 6 h is often
recommended) results in higher glycogen levels after
exercise than when ingestion is delayed for 2 h (11). It is
unnecessary for athletes who rest one or more days between
intense training sessions to practice nutrient timing about
glycogen replenishment provided sufficient carbohydrates
are consumed during the 24-h period after the exercise bout
(112). Nevertheless, consuming a meal or snack near the
end of exercise may be important for athletes to meet daily
carbohydrate and energy goals.
The type of carbohydrate consumed also affects postexercise
glycogen synthesis. When comparing simple sugars,
720 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
glucose and sucrose seem equally effective when consumed
at a rate of 1.0-1.5 g.kg-I body weight for 2 h; fructose
alone is less effective (113). With regard to whole foods,
consumption of carbohydrate with a high glycemic index
results in higher muscle glycogen levels 24 h after a
glycogen-depleting exercise as compared with the same
amount of carbohydrates provided as foods with a low glycemic
index (114). Application of these findings, however,
must be considered in conjunction with the athlete's overall
diet. When isocaloric amounts of carbohydrates or carbohydrates
plus protein and fat are provided after endurance
(115) or resistance exercise (116), glycogen synthesis rates
are similar. Including protein in a postexercise meal,
however, may provide needed amino acids for muscle
protein repair and promote a more anabolic hormonal
profile (33).
Conclusion statement. Twenty-five studies investigating
the consumption of a range of macronutrient composition
during the recovery period were evaluated. Nine
studies report that consumption of diets higher in carbohydrate
(>65% carbohydrate or 0.8-1.0 g carbohydrates'kg-I
body weight'h- 1
) during the recovery period increases
plasma glucose and insulin concentrations and increases
muscle glycogen resynthesis. Provided that carbohydrate
intake is sufficient, four studies show no significant benefit
of additional protein intake and two studies show no
significant effect of meal timing on muscle glycogen
resynthesis during the recovery period. Studies focusing
on carbohydrate consumption during recovery periods of 4
h or more suggest improvements in athletic performance.
(Evidence Gradeff = Fair). (www.adaevidencelibrary.com/
conclusion.cfm?conclusion_statement_id=25045 1).
DIETARY SUPPLEMENTS AND
ERGOGENIC AIDS
The overwhelming number and increased availability of
sports supplements presents an ongoing challenge for the
practitioner and the athlete to keep up-to-date about the
validity of the claims and scientific evidence. Although
dietary supplements and nutritional ergogenic aids, such as
nutritional products that enhance performance, are highly
prevalent, the fact remains that very few improve performance
(117-119) and some may cause concern.
In the United States, the Dietary Supplements and Health
Education Act of 1994 allows supplement manufacturers to
make health claims regarding the effect ofproducts on body
structure or function but not therapeutic claims to "diagnose,
mitigate, treat, cure, or prevent" a specific disease or
medical condition (117,120). As long as a special supplement
label indicates the active ingredients and the entire
ingredients list is provided, claims for enhanced performance
can be made, valid or not. The Act, however, made
the FDA responsible for evaluating and enforcing safety. In
2003, the US/FDA Task Force on Consumer Health
Information for Better Nutrition proposed a new system
for evaluating health claims that uses an evidence-based
model and is intended to help consumers determine
effectiveness of ergogenic aids and dietary supplements
more reliably (117). Although all manufacturers are
required by the FDA to analyze the identity, purity, and
strength of all of their products' ingredients, they are not
required to demonstrate the safety and efficacy of their
products.
Canada regulates supplements as medicine or as natural
health products (NHP). Products regulated in Canada
as NHP must comply with Natural Health Products
Regulations (2003) and manufacturers are allowed to make
a full range of claims (structure/function, risk reduction,
treatment, prevention) as supported by scientific evidence
(117). In Canada, sports supplements such as sport drinks,
protein powders, energy bars, and meal replacement products/beverages
are regulated by Health Canada's Canadian
Food Inspection Agency, whereas energy drinks, vitamin/
mineral and herbal supplements, vitamin-enhanced water,
and amino acid supplements fall under the NHP Regulations.
Anabolic steroids are considered drugs and are tightly
regulated under the Controlled Drugs & Substances Act.
Sports dietitians should consider the following factors in
evaluating nutrition-related ergogenic aids: validity of the
claims relative to the science ofnutrition and exercise, quality
ofthe supportive evidence provided (double-blinded, placebocontrolled
scientific studies vs testimonials), and health and
legal consequences of the claim (121,122). The safety of
ergogenic aids remains in question. Possible contamination
of dietary supplements and ergogenic aids with banned or
nonpermissable substances remains an issue of concern.
Therefore, sports dietitians and athletes must proceed with
caution when considering the use of these types of products.
Ultimately, athletes are responsible for the product they
ingest and any subsequent consequences. Dietary supplements
or ergogenic aids will never substitute for genetic
makeup, years of training, and optimum nutrition.
Both national [National Collegiate Athletic Association
(NCAA; www.ncaa.org), United States Anti-Doping Agency
(www.usantidoping.org)] and international sports organizations
[World Anti-Doping Agency (WADA; (www.wada-ama.org)]
limit the use ofcertain ergogenic aids and require random urine
testing of athletes to ensure that certain products are not
consumed. In Canada, the Canadian Centre for Ethics in Sport
(www.cces.ca) is the organization which checks for banned
substances.
The ethical use ofperformance-enhancing substances is a
personal choice and remains controversial (117). Therefore,
it is important that the qualified sports nutrition professional
keep an open mind when working with elite athletes to
effectively assess, recommend, educate, and monitor athletes
who contemplate using or actively take dietary supplements
and/or ergogenic aids (117). Credible and
responsible information regarding the use of these products
should be made available by qualified health professionals
Medicine & Science in Sports & Exercise, 721NUTRITION AND ATHLETIC PERFORMANCE
such as Board Certified Specialists in Sports Dietetics
(CSSD) who carefully evaluate the risk-benefit ratio,
including a complete dietary assessment.
It is beyond the scope of this article to address the
multitude of ergogenic aids used by athletes in North
America. From a practical perspective, however, most
ergogenic aids can be classified into one of four categories:
1.those that perforn as claimed; 2. those that may perform
as claimed but for which there is insufficient evidence of
efficacy at this time; 3. those that do not perform as
claimed; and 4. those that are dangerous, banned, or illegal
and, therefore, should not be used (122).
1.Ergogenic aids that perform as claimed
Creatine. Creatine is currently the most widely used
ergogenic aid among athletes wanting to build muscle and
enhance recovery (118,123-125). Creatine has been shown
to be effective in repeated short bursts of high-intensity
activity in sports that derive energy primarily from the
ATP-CP energy system such as sprinting and weight lifting
but not for endurance sports such as distance running
(32,117,126-128). Most of the researches on creatine have
been conducted in a laboratory setting with male athletes.
The most common adverse effects of creatine supplementation
are weight (fluid) gain, cramping, nausea, and
diarrhea (32,117,129). Although widely debated, creatine is
g.enerally considered safe for healthy adults, despite
anecdotal reports of dehydration, muscle strains/tears, and
kidney damage (130-132). Although the effects of longterm
use of creatine remain unknown, studies to date do not
show any adverse effects in healthy adults from creatine
supplementation (133). Nevertheless, health care professionals
should carefully screen athletes using creatine for any
risk of liver or kidney dysfunction or, in rare instances,
anterior compartment syndrome.
Caffeine. The potential ergogenic effects ofcaffeine may
be more closely related to its role as a CNS stimulant and the
associated decreased perception of effort as opposed to its
role in mobilizing of free fatty acids and sparing of muscle
glycogen (117,134). In 2004, WADA moved caffeine from
the restricted list to its Monitoring Programme. However,
caffeine is still a restricted substance by the NCAA, where a
positive doping test would be a caffeine level >15 /g.mL-1
of urine. New evidence shows that caffeine, when used in
moderation, does not cause dehydration or electrolyte
imbalance (135-138). However, when rapid hydration is
necessary, athletes should rely on noncaffeinated and
nonalcoholic beverages.
The use of high-energy drinks containing caffeine can be
ergolytic and potentially dangerous when used in excess or
in combination with stimulants or alcohol or other unregulated
herbals and should be discouraged (32,117,139-
141). Adverse effects of caffeine are anxiety, jitteriness,
rapid heartbeat, gastrointestinal distress, and insomnia, and
it could be ergolytic for novice users (134,142). There is
little evidence to promote use of caffeine alone as a weightloss
aid (118).
Sports drinks, gels, and bars. Sports drinks, gels, and
bars are commonly used as convenient dietary supplements
or ergogenic aids for busy athletes and active people. It is
important that qualified nutrition professionals educate
consumers about label reading, product composition, and
appropriate use of these products (before, during, and after
training and competition).
Sodium bicarbonate.Sodium bicarbonate may be an
effective ergogenic aid as a blood buffer (role in acid-base
balance and prevention of fatigue), but its use is not
without unpleasant adverse effects such as diarrhea
(117,143).
Protein and amino acid supplements. Current evidence
indicates that protein and amino acid supplements are
no more or no less effective than food when energy is
adequate for gaining lean body mass (30,31,117). Although
widely used, protein powders and amino acid supplements
are a potential source for illegal substances such as
nandrolone, which may not be listed on the ingredient label
(144,145).
2. Ergogenic aids that may perform as claimed but for
which there is insufficient evidence
The ergogenic aids that have claims as health and
performance enhancers include glutamine, 03-hydroxymethylbutyrate,
colostrum, and ribose (117). Preliminary
studies concerning these ergogenic aids are inconclusive
as performance enhancers. These substances are not banned
from use by athletes (www.wada-ama.org/en/prohibited
list.ch2).
3. Ergogenic aids that do not perform as claimed
The majority of ergogenic aids currently on the market
are in this category (122). These include amino acids, bee
pollen, branched chain amino acids, camitine, chromium
picolinate, cordyceps, coenzyme Q10, conjugated linoleic
acid, cytochrome C, dihydroxyacetone, y-oryzanol, ginseng,
inosine, medium-chain triglycerides, pyruvate, oxygenated
water, and vanadium. This list is by no means
exhaustive, and it is likely that other substances would be
best placed in this category. Similarly, it is possible for any
ofthese compounds to eventually move from this to another
category after appropriate scientific inquiry and evaluation.
To date, however, none of these products has been
shown to enhance performance and many have had adverse
effects (122).
4. Ergogenic aids that are dangerous, banned, or illegal
The ergogenic aids in this category should not be used
and are banned by WADA. Examples are androstenedione,
722 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
dehydroepiandrosterone, 19-norandrostenedione, 19-norandrostenediol,
and other anabolic, androgenic steroids,
Tribulus terrestris, ephedra, strychnine, and human growth
hormone. Because this is an evolving field, sports dietitians
need to consistently consider the status of various nutritional
ergogenic aids.
The Vegetarian Athlete
The Position Statement of the American Dietetic Association
and Dietitians of Canada on vegetarian diets (2003)
provides appropriate dietary guidance for vegetarian athletes.
This article provides additional considerations for
vegetarians who participate in exercise. Well-planned vegetarian
diets seem to effectively support parameters that
influence athletic performance, although studies on this
population are limited (31,146). Plant-based high-fiber diets
may reduce energy availability. Monitoring body weight and
body composition is the preferred means of determining
whether energy needs are met. Some individuals, especially
women, may switch to vegetarianism as a means of avoiding
red meat and/or restricting energy intake to attain a lean body
composition favored in some sports. Occasionally, this may
be a red flag for disordered eating and increase the risk for
the female athlete triad (72,73). Because of this association,
coaches, trainers, and other health professionals should be
alert when an athlete becomes a vegetarian and should ensure
that appropriate weight is maintained.
Although most vegetarian athletes meet or exceed
recommendations for total protein intake, their diets often
provide less protein than those of nonvegetarians (31).
Thus, some individuals may need more protein to meet
training and competition needs (31). Protein quality of
plant-based diets should be sufficient provided a variety of
foods that supply adequate energy is consumed (31).
Protein quality is a potential concern for individuals who
avoid all animal proteins such as milk and meat (i.e.,
vegans). Their diets may be limited in lysine, threonine,
tryptophan, or methionine (39).
Because plant proteins are less well digested than animal
proteins, an increase in intake of approximately 10%
protein is advised (15). Therefore, protein recommendations
for vegetarian athletes approximate 1.3-1.8 g-kg- 'd-1
(52). Vegetarians with relatively low energy intakes should
choose foods wisely to ensure protein intakes are consistent
with these recommendations.
Vegetarian athletes may be at risk for low intakes of
energy, fat, vitamins B12 , riboflavin, and D, calcium, iron,
and zinc, which are readily available from animal proteins.
Iron is of particular concern because of the low bioavailability
of nonheme plant sources. Iron stores of vegetarians
are generally lower than omnivores (52). Vegetarian athletes,
especially women, may be at greater risk for developing
iron deficiency or anemia. Routine monitoring of
iron status is recommended for vegetarian athletes, especially
during periods of rapid growth (i.e., adolescence
and pregnancy). Very low fat diets or avoidance of all
animal protein may lead to a deficiency of essential fatty
acids. Sport dietitians should educate novice vegetarian
athletes on resources for menu planning, cooking, and
shopping-especially high-quality plant protein combinations
and acceptable animal sources (i.e., dairy and eggs) as
well as foods rich in or fortified with key nutrients (calcium,
vitamins D, B12, and riboflavin, iron, and zinc) (52).
Roles and Responsibilities of the Sports Dietitian
As nutrition information advances in quantity and
complexity, athletes and active individuals are presented
with a myriad of choices and decisions about appropriate
and effective nutrition for activity and performance.
Increasingly, athletes and active individuals seek professionals
to guide them in making optimal food and fluid
choices. Although many athletes and active individuals
view winning or placing in an event to be the ultimate
evidence of the effectiveness of their dietary regimens,
sports dietitians should address the combined goals of
health and fitness, enhanced capacity to train, and optimal
athletic performance. Therefore, sports dietitians should be
competent in the following areas:
Roles
"* Conduct comprehensive nutrition assessment and
consultation
"* Educate in food selection, purchasing, and preparation
"* Provide medical nutrition therapy in private practice,
health care, and sports settings
"* Identify and treat nutritional issues that impact health
and performance
"* Address energy balance and weight management issues
"* Address nutritional challenges to performance (gastrointestinal
disturbances, iron depletion, eating disorders,
female athlete triad, food allergies, and supplement
use)
*. Track and document measurable outcomes of nutrition
services
* Promote wound and injury healing
* Oversee menu planning and design, including pre- and
postevent and travel
* Develop and oversee nutrition polices and procedures
* Evaluate the scientific literature and provide evidencebased
assessment and application
Responsibilities
"* Apply sports nutrition science to fueling fitness and
performance
"* Develop personalized nutrition and hydration strategies
"* Advise on dietary supplements, ergogenic aids, meal
and fluid replacement products, sports drinks, bars,
and gels
Medicine & Science in Sports & Exercise& 723NUTRITION AND ATHLETIC PERFORMANCE
"*Evaluate dietary supplements and sports foods for
legality, safety, and efficacy
"* Provide nutrition strategies to delay fatigue during
exercise and speed recovery from training
"* Help enhance athletic training capacity and performance
"* Participate in identifying and treating disordered eating
patterns
"* Provide nutrition strategies to reduce risk of illness/
injury and facilitate recovery
"* Promote career longevity for collegiate and professional
athlete and all active individuals
"* Recruit and retain clients and athletes in practice
"* Provide sports nutrition as member of multidisciplinary/medical/health
care teams .
"* Provide reimbursable services (diabetes medical nutrition
therapy)
"* Design and conduct sports team education
"* Serve as a mentor for developing sports dietetics
professionals
"* Maintain credential(s) by actively engaging in profession-specific
continuing education activities
The aforementioned responsibilities should be routine
expectations of sporting and sports medicine organizations
that employ qualified sports dietitians and of clients and
athletes seeking valid sports nutrition information and advice.
In 2005, the Commission on Dietetic Registration (CDR;
the credentialing agency of the American Dietetic Association)
created a specialty credential for food and nutrition
professionals who specialize in sports dietetic practice. The
Board Certification Specialist in Sports Dietetics (CSSD)
credential is designed as the premier professional sports
nutrition credential in the United States. Specialists in Sports
Dietetics provide safe, effective, evidence-based nutrition
assessment, guidance, and counseling for health and performance
for athletes, sport organizations, and physically active
individuals and groups. The credential requires current
Registered Dietitian (RD) status, maintenance of RD status
for a minimum of 2 yr, and documentation of 1500 sports
specialty practice hours as an RD within the past 5 yr. For
more information, readers are referred to the following Web
site: www.cdmet.org/whatsnew/Sports.htm.
ADA/DC/ACSM position adopted by the ADA House of
Delegates Leadership Team on July 12, 2000 and reaffirmed
on May 25, 2004; approved by Dietitians of Canada
on July 12, 2000 and approved by the American College of
Sports Medicine Board of Trustees on October 17, 2000.
The Coaching Association of Canada endorses this position
paper. This position is in effect until December 31, 2012.
ADA/DC/ACSM authorizes republication of the position, in
its entirety, provided full and proper credit is given. Readers
may copy and distribute this article, providing such
distribution is not used to indicate an endorsement of
product or service. Commercial distribution is not permitted
without the permission of ADA. Requests to use portions
of the position must be directed to ADA headquarters at
800/877-1600, ext 4835, or ppapers@eatright.org.
AUTHORS
- American College of Sports Medicine: Nancy R. Rodriguez, PhD,
RD, CSSD, FACSM (University of Connecticut, Storrs, CT)
- American Dietetic Association: Nancy M. DiMarco, PhD, RD,
CSSD, FACSM (Texas Woman's University, Denton, TX)
- Dietitians of Canada: Susie Langley, MS, RD, CSSD (69 McGill
Street, Toronto, ON, Canada)
REVIEWERS
- American Dietetic Association:
Sharon Denny, MS, RD (ADA Knowledge Center, Chicago, IL);
Mary H. Hager, PhD, RD, FADA (ADA Government Relations,
Washington, DC)
Melinda M. Manore, PhD, RD, CSSD (Oregon State University,
Corvallis, OR)
Esther Myers, PhD, RD, FADA (ADA Scientific Affairs, Chicago, IL);
Nanna Meyer, PhD, RD, CSSD (University of Colorado, Colorado
Springs, CO)
James Stevens, MS, RD (Metropolitan State College of Denver,
Denver, CO)
Jennifer A. Weber, MPH, RD (ADA Government Relations,
Washington, DC)
- Dietitians of Canada:
Rennie Benedict, MSc, RD (Department of Kinesiology &Applied
Health, University of Winnipeg, Winnipeg, MB).
Marilyn Booth, MSc, RD (Registered Dietitian and Exercise
Consultant, Ottawa, ON)
Patricia Chuey, MSc, RD (Manager Nutrition Affairs, Overwaitea
Food Group, Vancouver, BC)
Kelly'Anne Erdman, MSc, RD (University of Calgary Sport
Medicine Centre, Calgary AB)
Marielle Ledoux, PhD, PDt (Department of Nutrition, Faculty of
Medicine, Universit6 de Montr6al, QC)
Heather Petrie, MSc, PDt (Nutrition Cosultant, Halifax, NS)
Pamela Lynch, MHE, PDt (Nutrition Counseling Services &
Associates; Mount Saint Vincent University, Department of Applied
Human Nutrition, Halifax, NS)
Elizabeth (Beth) Mansfield, MSc, RD, PhD Candidate (McGill
University, Montreal, QC)
American College of Sports Medicine:
Susan Barr, PhD, RDN (University of British Columbia, Vancouver,
BC)
Dan Benardot, PhD, DHC, RD (Georgia State University, Atlanta,
GA)
Jacqueline Berning, PhD, RD (University of Colorado Springs,
Colorado Springs, CO)
Andrew Coggan, PhD (Washington University School of Medicine,
St. Louis, MO)
Melinda Manore, PhD, RD (Oregon State University, Corvallis,
OR)
Brian Roy, PhD (Brock University, St. Catharines, ON)
Assistance from Lisa M.Vislocky, PhD, University of Connecticut,
Storrs, CT, in preparing the references is acknowledged.
APC WORKGROUP
Christine M.Palumbo, MBA, RD (chair); Pat M. Schaaf, MS, RD;
Doug Kalman, PhD, RD, FACN (content advisor); Roberta Anding,
MS, RD, LD, CDE, CSSD (content advisor).
The authors thank the reviewers for their many constructive
comments and suggestions. The reviewers were not asked to
endorse this position or the supporting paper.
724 Official Journal of the American College of Sports Medicine http://www.acsm-msse.org
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