Nutritional Considerations

 Research shows that, regardless of the sport, an athlete’s
diet plays a critical, if not essential, role in performance.
 Yet misinformation and misconceptions persist among
coaches and athletes regarding what constitutes an
adequate diet.
 We will first examine available evidence concerning the
dietary knowledge and practices of coaches and athletes.
 Then we will examine dietary recommendations for healthy
eating, including the roles of carbohydrates, proteins, fats,
vitamins and minerals.
 Next, we will look at evidence pertaining to protein
supplementation and other ergogenic aids.
 Special attention will be given to the sport of wrestling,
which has been plagued with the problem of athletes
attempting to lose body weight rapidly by dehydration, and
a simple method is provided to assess an athlete’s ability to
rehydrate adequately.
 We will discuss the relationship between nutrition and
recovery from injury.
 Finally, we will use our 3 day calorie tracker to incorporate
into our fitness program in the computer lab
A brief history of sports nutrition…
 Specific text on the diet
of ancient athletes are
 Human muscle energy
metabolism began to be
studied in the late 19th
 Milo of Croton – 6th century BC
 Was the first Olympian
 Would consume 20 pounds of bread and meat a day
= 16,000 calories/day
 Nathan Zuntz – 1911
 Was a psychologist who discovered you need to combine
carbohydrates and fat together to help increase energy
 Boston Marathon Studies – 1923
 A group of scientist we called in to test marathon
runners after their race.
 Their conclusions found that the majority of marathon
runners had low blood sugar levels after the race.
Low blood sugar levels = hypoglycemia
 In the next Boston Marathon, a few runners were
encouraged to consume high-carbohydrate food.
 Conclusion = consuming high carbohydrate prevented
lower glucose level and improved running time to
complete the race
 Harvard Dog Studies – 1932
 Scientist took 2 sled dogs
 Increased the sled dogs food for 4 hours, 6 hours, 17
hours, 23 hours
 Provided more carbohydrates after the rest period
 Dr. Robert Cade – 1965
 An ephrologist (kidney specialist) who studied physiology of exercise
 Came to University of Florida College of Medicine
 Put together a team who began to work on answering the famous
question asked about the football team
“Why don’t football players urinate after a game?”
At the time, basic exercise wisdom discouraged athletes from replenishing
liquids lost due to sweating during the game
The team lost so much fluid, that they had none left to form urine
 Dr. Robert Cade began to develop a hydration drink (combined with
sugar and salt) that could be absorbed more quickly.
 Thus, this became the basis of Gatorade
 He first used Gatorade on guinea pigs(who were the JV
 Noticed that in the scrimmage during practice the
Varsity would over power the JV team
 After consuming the Gatorade beverage, in the second
half, JV overpowered V
 Proper nutritional knowledge is imperative for all
individuals, but especially for those involved in
athletic competitions (Jacobson, Sobonya, & Ransone,
 An athlete’s diet has a direct impact on performance,
recovery from training and competition, resistance to
environmental extremes, recovery from injury, and, to
some extent, likelihood of injury.
 In essence, diet influences virtually all aspects of
sports participation.
 Most athletes (68%) were familiar with the food
groups and 71% reported incorporating them into their
diet, but Parr et al. (1984) also demonstrated that
athletes largely relied on parents for information about
nutrition – followed by TV commercials and
 Although the knowledge of most parents concerning
nutrition cannot be measured, it is probably safe to
assume that both parents and the media represent, at
best, marginal sources of current nutritional advice
always or often during their college carriers.
Nutrients: An Overview
 According to the American Dietetic Association (2009),
eating correctly for sports performance will
Help the athlete train longer and at a higher intensity
Delay the onset of fatigue
Promote recovery
Help the athlete’s body adapt to workouts
Improve body composition and strength
Enhance concentration
Help maintain healthy immune function
Reduce the chance of injury
Reduce the risk of heat cramps and stomachaches
 Although a comprehensive investigation of both
macronutrients (required in large amounts) and
micronutrients (required in small, or trace, amounts) is
beyond the scope of this text, a brief review of the six
classes of nutrients is presented.
Carbohydrates, fats, and proteins are the macronutrients,
and each is important in the diet.
The mix of these may change based on fitness levels,
exercise goals, and personal food preferences.
Vitamins and minerals are micronutrients that contribute
to metabolic reactions and tissue structure.
And finally, water is essential for substrate transport, waste
removal, and joint health (McArdle, Katch & Katch, 2009).
 Carbohydrates (CHO) are molecules that, by way of
their metabolic breakdown, provide energy for highintensity exercise.
 The specific forms of CHO used within the body are
glucose and glycogen (the storage form of glucose)
found in the blood, liver, and skeletal muscle.
 Carbohydrates consist of carbon, hydrogen, and
oxygen atoms, with the number of carbon atoms
ranging from three to seven.
 They fall into three general categories, based on the
complexity of the molecule.
 the simplest forms of CHO are the monosaccharides
(a single molecule), which include sugars such as
fructose, glucose (blood sugar), and galactose.
 The next group is the disaccharides (two
monosaccharide molecules combined), which include
commonly known sugars such as lactose (milk sugar),
sucrose (the most common form of sugar in the diet),
and maltose.
 The complex carbohydrates are known as
polysaccharides (10 to thousands of
monosaccharides linked together) and include
compounds such as glycogen, starch, and cellulose
(dietary fiber).
*Single molecule
*fructose, glucose,
and galactose
*lactose, sucrose,
*10 to thousands of
linked together
*glycogen, starch,
 The majority of dietary CHO is derived from plant
sources, primarily grains, seeds, fruits, and vegetables.
 In a practical context, carbohydrates are classified as
either simple (monosaccharides) or complex.
 In general, complex CHO contain more nutrients and
fiber than simple CHO do.
 The most common form of dietary CHO intake is from
simple sugars, primarily foods high in sucrose
 Soft drinks, candies, and cereals (high in sugar).
 Although high in caloric content, these foods
stimulate insulin release , cause fluctuations in blood
glucose levels, and provide little in any way of other
nutrients; therefore, they are often referred to as
“empty calorie” foods.
 A superior form of dietary CHO is derived form eating
more complex CHO or whole-grain cereals and breads,
vegetables, and fruits.
 The CHO in these foods is in the form of starch found in
the cereals and breads or cellulose found in leaves, stems,
roots, seeds, and coverings of plants.
 An added benefit of consuming complex CHO is that they
typically contain dietary fiber (indigestible CHO), which
may lower cholesterol absorption and is also beneficial to
the digestive tract.
 Daily fiber intake should be between 21 g and 38 g
depending on gender and age (McArdle et al., 2009).
 Another excellent source of CHO is fruits, which can provide a
significant amount of CHO in the form of fructose.
 Fructose, a monosaccharide, is much sweeter than surcose;
however, the benefit of fructose is that it “does not stimulate
pancreatic insulin secretion” and, as a result, “helps to stabilize
blood-glucose and insulin levels” (McArdle et al., 2009).
 An added benefit of
whole-grain breads,
cereals, fruits, and
vegetables is that they
typically contain a wide
variety of other nutrients
and, as such, help to
provide a balanced diet.
 Although the classifications of simple and complex CHO
often are suitable to describe foods containing CHO, these
classifications do not represent the way both simple and
complex CHO are hydrolyzed and absorbed by the body
(Manore, Meyer, & Thompson, 2009)
 Foods are now also classified as producing either high,
moderate, or low glycemic responses.
 Foods classified as having a high glycemic response
typically result in a large and rapid rise in blood glucose
and insulin, followed by a rapid decrease in blood glucose.
 Those foods with a lower glycemic response cause a
steadier rise and decline in blood glucose and insulin.
 Low glycemic index CHO improve diabetes
management, reduce the risk of heart disease, reduce
hunger and keep a person fuller for longer, and
prolong physical endurance, whereas high glycemic
CHO help refuel carbohydrate stores after exercise.
Carbohydrate & Muscle
 Muscles require CHO as a fuel source during exercise.
 The recommended percentage proportion of CHO in
the diet should range between 60% and 70% of the
total calories consumed daily, depending on the
exercise frequency and intensity.
 Regardless of the type of CHO consumed, they all
provide approximately 4 kal/g CHO.
 The average person stores approximately 1500 to 2000
kcal of CHO, the majority of which is in the form of
muscle and liver glycogen, with a small portion
available and blood glucose (McArdle et al., 2009).
 All individuals need to
consume carbohydrates
to maintain body
functions or support
exercise; however,
athlete engaging in
different activities need
to consume
carbohydrates at greater
levels than sedentary
individuals do.
Carbohydrate (Glycogen) Loading…
 As stated earlier, the majority of CHO in the body is
stored in the skeletal muscles and liver in the form of
 Physiologically, it is to the athlete’s advantage if the
total amount of stored glycogen can be increased prior
to a competition.
 Athletes involved in aerobic sports, especially those
with durations in excess of 60 minutes, benefit the
most from an increased level of stored glycogen.
Carbohydrate (Glycogen) Loading…
 Essentially, the process of
CHO loading involves the
systematic decrease of dietary
CHO intake in conjunction
with a significant increase n
exercise intensity.
 Early procedures for CHO
loading were particularly
Spartan in nature, requiring
multiple days of intense
exercise (depletion phase)
combined with dietary
restriction of CHO intake.
Carbohydrate (Glycogen) Loading…
 Ironically, although such protocols often did result in an
increase in stored glycogen, the negative impacts often
outweighed the benefits in performance.
 These included severe physical fatigue associated with the
depletion phase, along with negative emotional changes
such as hyperirritability.
 In addition, another problem related to CHO loading is
that for ever gram of CHO stored, an additional 2.7 g of
water is also stored.
 As such, the process of CHO loading results in an overall
increase in body weight that, in sports such as distance
running, may represent a performance detriment.
Carbohydrate (Glycogen) Loading…
 Research verified that a properly executed regimen of CHO
loading can boost the level of stored glycogen from the
normal 1.7 g of glycogen/100 g of muscle tissue to 4 to 5 g of
glycogen/100 g of muscle tissue.
 A typical modified regimen begins approximately one week
prior to competition and includes a gradual tapering of
physical activity accompanied with a slight increase in
CHO ingestion.
 Exercise (75% maximal O2 consumption over the first 3
days follows a steady decline in total time 1.5 hrs/day to 50
mins) while CHO consumption is maintained at 50% of
total caloric intake.
Carbohydrate (Glycogen) Loading…
 Over the next 3 days, exercise time is decreased to
about 10-15 minutes while CHO consumption is
increased to 75% of total caloric intake.
 A normal protein and fat intake is maintained.
 A high-CHO meal is then consumed on the day of the
competition (McArdle et al., 2009)
Carbohydrate and Exercise
 CHO stored in muscle and liver as glycogen
 -350 grams in muscle; - 90 grams in liver
 -1800 calories in all
 Trained muscle can carry more glycogen
 Small amount circulating as blood glucose
 Excess CHO stored as fat when glycogen stores are full
(Jon Vredenburg, MBA, RD, CSSD, LD/N, HFS)
Carbohydrate and Exercise
 High intensity makes CHO the preferred substrate.
 50-60% of energy over 1-4 hours of continuous (70%
capacity) exercise comes from CHO.
 Since CHO is a primary fuel source – low levels lead to
 Fatigue = when exercise continues to the point that
compromises liver and muscle glycogen supply.
 2 hour strenuous workout can deplete liver and muscle
(Jon Vredenburg, MBA, RD, CSSD, LD/N, HFS)
Carbohydrate and Exercise
 Rate of ingested carbohydrate oxidation is limited to -60
grams per hour (240 calories).
 Intestinal transports become saturated.
 CHO combinations (i.e. glucose +fructose) have greater
oxidation rates.
 Overall carbohydrate oxidation rates usually well above 500
 In moderate to higher intensity activities.
 Clarifies the need for adequate fueling throughout training
cycles (between sessions)
Jeukendrup. A (ED) (2010). Sports Nutrition from lab to kitchen, Meyer & Meyer Sport
Where the fuel could be used…
*Brain storage has 20% at
Fat (Lipids)
 Fats serve a variety of functions in the body, including:
 Providing energy for muscle contraction
 Insulation
 Primarily in the form of subcutaneous fat
 Protection of vital organs such as the kidneys and heart
 Dietary fats are either simple or complex, depending
on their specific molecular structure.
 Fats, like CHO, consist of carbon, hydrogen and
oxygen atoms; however, the ration of hydrogen to
oxygen is far greater in fats than in carbohydrates.
Fat (Lipids)
 Depending on their
molecular structure, fats
can exist either in liquid
(oils) or solid form.
 Simple fats consist of two
 Glycerol
 Fatty acid
 Can be either saturated
or unsaturated
Fat (Lipids)
 The term saturated
describes the fact that in
this form of fat all of the
available bonding sites on
the fatty acid molecule are
occupied by a hydrogen
 Most dietary sources of
saturated fats are derived
from animal sources (i.e.
beef, pork, poultry, and
dairy products) and are
generally solid at room
Fat (Lipids)
 Unsaturated fats, as the
term implies, are
structured in such a way as
to prevent all of the
available bonding sites
from being occupied by a
hydrogen atom.
 The majority of
unsaturated fats exist in
two forms,
monounsaturated and
Fats (Lipids)
 Monounsaturated fat
 Include a single site on
the carbon chain where
a double bond exists,
thus preventing
hydrogen atoms from
bonding at the site.
 Polyunsaturated fats
 Have two or more
double bonds and, as
such, have at least two
sites that cannot be
occupied by hydrogen
Fat (Lipids)
 The recommended percentage proportion of fats in
the diet should be 30% or less of the total calories
consumed daily (McArdle et al., 2009).
 It is recommended that saturated fats make up only
10% of total fats (20-25g based on 2000 – 2500
kcal/day); therefore, the majority of fats consumed
should be unsaturated.
 This helps avoid the problems attributed to excessive
consumption of saturated fats, including high
cholesterol and cardiovascular disease.
Fat (Lipids)
 Dietary sources of fats, as
stated earlier, are animal
products such as beef,
poultry, and pork.
 Other sources include
dairy products, such as
milk, butter, and cheese.
 In addition, plant sources
of fats include nuts and
plant oils such as corn oil,
olive oil, and soybean oil.
Fat (Lipids)
 In addition to CHO, fat is an important source of
energy during rest and exercise.
 Both CHO and fats are oxidized for energy at the same
 The proportion of energy that comes from CHO and
fats is dependent on the duration, intensity, and type
of exercise as well as the athlete's fitness level and
meal eaten prior to exercise (Manore et al., 2009).
 Regardless of the type of fat consumed, all forms
provide approximately 9 kcal/g; therefore, fats are
calorie dense.
Fat (Lipids)
 One tablespoon of butter has the same kilocalories as
4 cups of chopped broccoli (100 kcal).
 The available amount of energy in the form of stored
body fat is significantly greater than what is available
from CHO.
 For example, the available energy in a 70-kg person
who has 18% body fat is calculated to be around
113,400 kcal.
Fat and Exercise
 Potentially unlimited source of fuel during aerobic
 150 pound (68 kg) runner in a marathon at a 8 min/mile
pace burns 3245 kcal.
 One pound of fat = 3500 kcal.
 Improving fatty acid oxidation during exercise
preserves muscle glycogen.
 Result of training adaptations.
Fat burning, simplified…
 Fatty acids broken down in the mitochondria
generate Acetyl CoA
entry in the Kreb’s (TCA)
 Accumulation of Acetyl CoA occurs in absence of
 Physical activity becomes compromised
 Carbohydrate substrates needed to sustain Kreb’s Cycle
 Fat burns in a carbohydrate flame
 As with both carbohydrates and fats, proteins also contain
carbon, hydrogen, and oxygen atoms in their molecules.
However, proteins also include nitrogen and, as such, they
are unique molecules compared to the other nutrients.
Protein molecules are assembled by combining amino
acids using peptide bonds to form large, complex
The majority of the body’s protein is found in muscle and
connective tissues.
Proteins are also found in the body fluids and in the blood
from thousands of different enzymes and structures related
to blood clotting such as fibrin and fibrinogen
 In addition, muscle protein is used as an energy source
during prolonged exercise, producing as much as 10%
to 15% of the energy requirements for long duration
 Research suggests that a regimen of regular aerobic
exercise enhances the body’s ability to generate energy
from the metabolism of proteins (Sumida & Donovan,
 The body builds proteins
from the amino acids that
are available from the
protein that is consumed
in the diet.
 Of the 20 amino acids
required to construct the
body’s proteins, 8 cannot
be synthesized by the body
and must, therefore, be
ingested in the diet.
 These eight amino acids are known as “essential,”
implying that they must be present in the diet.
 They are isolucine, leucine, lysine, methionine,
phenylalanine, threonine, tryptophan, and valine.
 The best dietary sources of the essential amino acids
are eggs, meats, and dairy products, all known as
complete proteins.
 Incomplete proteins are those that lack one or more or
contain insufficient amounts of one or more of the
essential amino acids.
 They include foods found in the legume and grain
 Athletes who are on vegetarian diets must take care to
eat foods in the correct combination to provide all of
the essential amino acids.
 A solution to the problem is for such athletes to
include either eggs (ovolactovegetarian), milk
products (lactovegetarian), or both to ensure adequate
supplies of essential amino acids.
 Substance in foods made up of chains of amino acids
 Three categories of AA:
 Build, repair and maintain body tissues
 Provide energy if carbs and fats are in short supply
 4 calories per gram
Protein Supplementation…
 Because dietary protein is associated with building
muscle mass, many athletes are curious about the
benefits of extra protein consumption beyond that
found in regular diets.
 A recent study of 61 high school football players
reports that 64% are ingesting protein supplements in
an attempt to gain strength or improve performance
(Duellman et al., 2008).
 Unfortunately, the researchers also present the more
than 60% of these athletes believe there are no risks to
excessive protein intake.
Protein Supplementation…
 However, at least two problems are associated with the
practice of consuming additional protein.
 The first is that many sources of dietary protein also
contain a large amount of saturated fat, such as beef and
pork products.
 The second problem is that in certain cases the body
may be unable to eliminate the by-products of excess
protein breakdown efficiently, and, as such, organs such
as the liver and kidney are stressed.
Protein Supplementation…
 Today there is a huge commercial market for what are
commonly known as protein supplements, often sold
at health food stores, grocery chains, and sporting
good stores and through mail order and the Internet.
 Most of these products consist of meat by-products
that are processed into a powder form that is then
mixed with water or some other liquid and consumed
 Unfortunately, because these products are marketed as
food supplements, their purity is not monitored by the
Food and Drug Administration.
Protein Supplementation…
 In addition, many of them are extremely expensive on
a per-pound basis, often exceeding the cost of more
common sources of protein such as meat and dairy
Protein Supplements…
 Unfortunately, there is virtually no scientific research
that supports the premise of protein supplementation
enhancing muscle development.
 Muscle mass does not increase simply by eating highprotein foods or special preparations of amino acids
(McArdle et al., 2009).
Protein Supplements…
 At present, available research indicates athletes involved in
intense training, particularly strength training, need to
consume between 1.2 g and 1.8 g of protein for each
kilogram of body weight, whereas the sedentary person or
light exerciser needs to consume only 0.83 – 1.2 g/kg.
 To put this into a practical context, the calculated protein
requirements for a 60-kg would range from 72g to 108g per
 Eight ounces of broiled salmon provides approximately 62
g of protein, 8 ounces of lean sirloin steak provides
approximately 65 g of protein, and 8-ounce skinless
chicken breast yields a little over 70 g of protein
Protein Supplements…
 It can be seen that adequate protein to meet the daily
requirements of an athlete in heavy training can easily
be achieved through meals without the need of
additional supplements.
 Only growing infants and children, pregnanat or
nursing women, or adults suffering from certain
disease or injury states should consume more than the
recommended amount (McArdle et al., 2009).
Proteins and Exercise
 Protein used for growth and repair of tissue.
 If overall caloric intake is adequate
 Protein energy contribution to exercise inversely
proportional to available energy stores.
 Usually accounts for a small (>5%) amount of ATP
formed during endurance activity
 Vitamins are chemicals that are needed by the body in relatively
small amounts and, therefore, are classified as micronutrients.
 This should not be interpreted, however, to mean that vitamins
have little importance nutritionally.
 On the contrary, adequate amounts of vitamins are essential to
health and human performance.
 Vitamins serve a multitude of functions in the body, essentially
helping to regulate biochemical reactions such as energy
metabolism and cell and tissue generation, as well as serving
antioxidants (antioxidants protect structures such as cell
membranes from the damaging effects of free radicals that are
released during vigorous exercise).
 Vitamins contain no
caloric value and, as
such, do not directly
provide energy for
muscle contraction.
 So far, 13 specific
vitamins have been
identified and are
divided into two groups:
 Water soluble
 Fat soluble
 Water-Soluble group includes:
 Vitamin C (ascorbic acid)
 The B vitamins
B1, B2, B6, B12
Folic acid
Pantothenic acid
 Water soluble vitamins, with the exception of B12, are
not stored in the body, and excess amounts are
excreted via the kidneys and urine.
 Fat-soluble vitamins:
 Vitamins A, D, E, K
 Because of their solubility, they are stored in the fat
tissues of the body.
 In fact, excess consumption of fat-soluble vitamins
beyond what is recommended (in the United States
Allowance [RDA]) can result in buildup of and eventual
toxic reaction to the stored vitamin (McArdle et al.,
 There is no evidence that taking any vitamin in an amount
greater than the recommended level provides any sort of
performance enhancement.
 Athletes who consume balanced diets most likely are
getting adequate amounts of vitamins through their food
and beverage consumption.
 For athletes who are eating less than an ideal diet, a daily
multivitamin supplement that meets the RDA’s for all
necessary vitamins is advised.
 There is no evidence that vitamins marked as organic or
natural provide any benefit over those that are
manufactured synthetically and often sold at a lower cost.
 To be effective, vitamins
should be taken after
meals to optimize
absorption because they
work best in the
presence of other
 Key regulators in energy metabolism
 Offer protection against oxidative damage
 Supports growth and development
 If take too many may have a reverse effect
 Minerals are elements that must be consumed regularly to
ensure normal body functions.
They provide structure, help maintain normal heart
rhythm, assist muscle contractility, promote neural
conductivity, and regulate metabolism (McArdle et al.,
A typical over-the-counter daily vitamin and mineral
supplement usually includes many minerals.
As is the case with vitamins, there is no scientific evidence
that consuming minerals in excess of the RDA provides
that advantage in performance.
In addition, a well balanced diet can provide all the
necessary dietary minerals.
 The best known minerals are iron and calcium.
 Perron and Endres (1985) investigated the nutritional
habits of 31 female high school volleyball players.
 Seventy percent (70%) of them did not meet the RDAs
for energy (total calories), calcium, and iron.
 Iron is associated with red blood cell formation,
oxygen storage and transport, and enzymatic reactions
related to protein and carbohydrate metabolism.
Iron is available from plant and animal sources.
It is best absorbed from animal sources.
RDA for iron is 10 mg for males and 18 mg for females.
Females require more iron than males, especially during
their first menstrual cycle.
 Inadequate intake of iron or limited rates of iron
absorption can cause anemia, resulting in lethargy and
shortness of breath.
 Physically active individuals need only include the RDA
levels of iron in their daily diet; they should steer clear of
supplements unless a deficiency exists because excess iron
can be very toxic to the body (McArdle et al., 2009).
 However, endurance, vegetarian, and female athletes
may want to consult a physician for assessment and
maintenance of proper iron balances.
 Current thought among sports scientist is that iron
deficiency is common in athletes involved in
endurance sports (Pattini & Schena, 1990).
 It is speculated that iron may be lost through sweating,
gatrointestinal bleeding, menstrual bleeding, and
excessive red blood cell distribution (hemolysis) in the
blood vessels.
 A convenient method of supplementation is a daily
multivitamin and mineral tablet.
 Numerous products are available over the counter that
provide the adult RDA of iron.
 Calcium is metabolically
associated with normal
bone and dental health.
 It is the most prevalent
mineral in the body and
is easily obtained in the
diet by consuming diary
products or other
foods/beverages that
have been artificially
fortified with calcium.
 Scientific evidence suggests that some groups of
athletes may be at an increased risk of calcium
deficiency (Deuster et al., 1986; Moffatt, 1984).
 Female athletes involved in aerobic running sports, as
well as gymnasts, have been found to be consuming
too little calcium.
 This places these people at risk for inadequate bone
development and can contribute to osteopenia or
osteoporosis in later life.
 In these high-risk groups, calcium supplementation is
most certainly warranted.
 Again, it is important to note that a supplement that
provides the RDA is appropriate because consuming
calcium in excess of this level may lead to other
 The recommended daily dosage for adolescent females
is 1500 mg.
 Serve as structural components of the body
 Major minerals and trace minerals
 Stimulate muscle and nerve activity as well as
hemoglobin synthesis
 Electrolytes regulate fluids in and out of the cells
 Sodium and Potassium
 Maintain relative acidity or alkalinity of blood and
 Control acid-base balance
 There is virtually no debate in the sports medicine
community regarding the importance of water, not
only to human performance but to survival as well!
 Water
 Housed in two general locations:
 Are extracellular fluids
 Intracellular fluids
 Water is constantly being lost through normal body
 At rest the adult
 Under conditions of heavy exercise, especially in
conditions of high ambient temperature, water
requirements can escalate to 5 L to 10 L daily (McArdle et
al., 2009).
 During exercise, a significant amount of body water is lost
to eliminate metabolic heat.
 The circulatory system transports this excess heat by way of
the blood to the skin, where,
 The process of sweat evaporation from the skin surface
can easily result in
 The most serious consequence of profuse sweating is
 A reduction of body weight of 2-5% can result in
reduced performance and stress on internal organs.
 To calculate the reduction in body weight due to fluid
 Take the number of pounds lost in activity and divide
the number by the pre-practice weight.
 This
 Current recommendations suggest that for every
pound of water weight lost, an athlete should consume
20 – 24 oz of fluid (McArdle et al., 2009).
 One
 Even a 2% water deficit can impair performance.
 Hydration status influenced by:
 Fitness
 Intensity
 Temperature
 Clothing
 acclimation.
Jeukendrup. A (ED) (2010). Sports Nutrition from lab to kitchen, Meyer & Meyer Sport
 Proper hydration =
 There is no ‘one fits all’ amount
 Weight (in pounds) / 2 = Ounces Water needed at rest
 General guideline
Jeukendrup. A (ED) (2010). Sports Nutrition from lab to kitchen, Meyer & Meyer Sport
Sweat Composition…
 Physical
 Sweat contains
 1 liter of sweat could contain up to 2 grains of sodium
 Potential for sodium imbalance main concern
 Cramping intervention
Bernadot, D. (2006). Advanced Sports Nutrition
Sweat Mineral Composition
 Sodium
 Chloride
 Potassium
 Magnesium
 Calcium
460-1840 mg/L
710-2840 mg/L
160-390 mg/L
0-36 mg/L
0-120 mg/L
Dunford. M. (Ed). (2006) Sports Nutrition: A practice mineral for professionals
Hydration Guidelines…
 Before exercise:
 During exercise:
 After exercise:
Source: American College of Sports Medicine.
Extreme Conditions…
 Physical fitness dictates heat tolerance
 High body fat =
 Problems
 Have an emergency action plan (EAP)
 Acclimatization:
Sweat starts at a lower core temperature
Reduction in salt losses in sweat; more sweat produced
Typically takes two weeks
Sports Drinks…
 Contain
 Adding protein has had equivocal results
 Many flavors and variations
 8 ounce serving
50 calories
14 g CHO
110 mg sodium
30 mg potassium
Saunders, M. Kane. M (2004). Effects of a carbohydrate-protein beverage on cycling endurance and muscle
Sports Drinks…
 The
 Cool and non-carbonated
 Sodium
 Provides the drive to drink; maintains proper sodium balance
 At concentrations
 High CHO content leads to GI distress
 Multiple
 Maltodextrins used to enhance palatability (less sweat)
Sports Drink vs. Water
 Water
 As intensity and duration increase sports drinks are
 Exogenous energy source aids performance
Sweat Rate…
 Amount of sweat lost in an hour
 Determine pre-exercise weight
 Determine
16 oz = 1 pound
 Determine post-exercise weight
 Provides individualized guidance
 Sweat Rate
 Helps
 Under-hydration
 Rehydrate with an amount greater than the losses
Special Considerations..
Female Athletes…
 As more women become involved in organized sports,
 Perron and Endres (1985) find that 81% of female
volleyball players report a concern about body weight;
perhaps their low caloric intake was part of an attempt
to lose weight.
Special Considerations..
Female Athletes…
 Loosli and Benson (1990) surveyed 76 adolescent
female gymnast and their results indicate that
Special Considerations..
Female Athletes…
 Because gymnastics place great emphasis on being
 However, gymnastics is not alone.
 It was also reported that 47% of athletes in “lean”
X-Country and Endurance Sports
 Upgrove and Achterberg (1990) investigated the
nutritional habits of male and female high school
cross country runners.
 Ironically,
 In addition, they reported that coaches were their
preferred source of information on nutrition.
 The sport of
 Wrestling is one of only a few sports that match
participants on the basis of weight.
 Yet,
 Unfortunately, the only form of rapid weight loss,
short of surgical removal of tissue, is through
 Water weights approximately
 Wrestlers have been known to use a variety of methods
to rapidly lose weight, including fluid restriction, the
use of laxatives and diuretics, artificially induced
sweating, and even starvation.
 There is no definitive proof that such tactics actually
present an advantage, and there are plenty of reasons not
to engage in such behavior.
 The
 The long-term effects are not known at this time; however,
there is speculation in the scientific community that these
techniques may interfere with normal growth and
development of the adolescent athlete.
 In an effort to reduce the likelihood of unhealthy
weight-loss practices (“weight cutting”) in high school
wrestlers, the state of Wisconsin instituted the
Wrestling Minimum Weight Project (WMWP) in 1989
(Oppliger et al., 1995).
 This project involved the establishment of minimum
weight-loss and body-composition criteria that limit
all participants to a body fat minimum of 7% and a
maximum of 3 lb of weight loss per week.
Many athletes do
2. Carbohydrate consumption should be 6-10 g/kg body
mass (2.7-4.5 k/lb body weight). Carbohydrates
maintain blood glucose levels during exercise and
replace muscle glycogen.
 Protein recommendations for endurance and strength-
trained athletes range from 1.2 to 1.7 g/kg body mass
(0.5-0.8 g/lb body weight.)
 For example, to compute the recommended 1-day
protein intake for an 85-lb female gymnast, make the
following calculations:
Body weight in kilograms = 38.6
(85 lb / 2.2 lb per kg)
=46.4 g daily protein requirement
A chicken breast (8oz) will provide the protein requirement
 Fat intake should range from 20% to 30% of total
energy intake.
 Athletes participating in sports that stress lean builds
and low body fat tend to follow diets too low in total
 Athletes tend to consume too many calories in the
form of junk food, which is laden with fat and extra
 Many athletes’ diets are deficient in at least some
important minerals, such as calcium, iron, and zinc.
However, the
(McArdle et al., 2009).
Exercise and Metabolism…
 ATP is the energy currency of the body
 Power
 Three different energy systems to get ATP
 Phosphagen system
Very short term
 Anaerobic system
 Short term
 Aerobic system
 Unlimited capacity to make ATP
Hargreves, M & Spiret L (2006)
Phosphagen System..
 Used in short burst of exercise
 Anaerobic
 Phosphate group removed by creatine kinase
 Limited amount of PCr stored in muscle tissue
 Energy supply lasts about 8 to 10 seconds
McArdle W. Katch, F & Katch V (2005) Sports and Exercise Nutrtion
Anaerobic Glycolysis
 Also known
 Stored glycogen is converted to energy
 Can provide energy for about 90 – 120 seconds
 ATP is made with pyruvate as an end product
 Lactic acid is formed from pyruvate
McArdle W., Katch F & Katch V (2005) Sport & Exercise Nutrition
Aerobic System
 After –
 With oxygen present, gerater yield of ATP
 Fuel sources with aerobic respiration
 Muscle glycogen
 Liver glycogen
 Exogenous fuel
 Fatty acids,
McArdle W., Katch F & Katch V (2005) Sport & Exercise Nutrition
Eating for Muscle…
 Adding
 Anabolism = constructive metabolism
 Protein needs are increased to double RDA
 Use
McArdle W. Katch, F & Katch, V (2005). Sports & Exercise Nutriton
Eating for Muscle…
 Gaining
 Fuel basal needs, activity and growth
 Harder gainer or an under-eater?
 Rapid weight gain may mean more fat deposition
 “Bulk up” (lean mass) vs “bulk out” (fat mass)
Additional Tips
 Feature
 Add ‘energy dense’ foods to the diet
 Stack foods with add-ons
 Potato with toppings
 Dried fruit and nuts on cereal
 Don’t drink water right before meals
 Monitor caffeine to promote rest
Content adapted from: Litt, A (2004) Fuel for Young Athletes
Adding energy dense foods
 Choose This…
Cup of Granola
Bag of Peanuts
Sandwich on a sub
Sports Drink 20 oz 135
Over This… Calories
Cup of cheerios
Bag of pretzels
sandwich on bread 300
english muffin
Mistakes Commonly Made
 These
Over-eat protein
2. Under-eat carbohydrates
3. No dietary variation
Safe Weight Loss
 Best
 Look at
 Common recommendation:
 1-2 pound per week decrease
 Larger
 Greater number and volume of adipose cells
 Are there ‘bad’ foods?
 General rule of thumb: The less processed it is, the
better nutritional benefits you will receive.
Menu Planning
 Fueled
 Pre-exercise meals
 Give ample time for digestion
 Provide the correct fuel matrix
 Minimize potential GI stressors
 Stress food safety
 Know their tastes
 Know your budget
Menu Planning
 Early events
 Top
 Try
light snack the morning of even (1-2 hrs. before)
During Exercise…
 Replace fluid losses
 Exogenous
 Endurance:
 30-60 g CHO/hr (common fuels used in endurance events:
jellybeans, gels, energy bars, sports drinks)
 Begin intake shortly after activity begins
 80-90 g CHO/hr for ultra endurance (> 3 hours)
Multiple transportable carbs
Position statement of the American diabetic association, dietitians of Canada
Common CHO amounts
 32 ounces sports drink = 60 g
 4 fig cookies = 42 g
 Energy bar = 45 g
 Banana = 30 g
 Carb gel pack = 28 g
 Handful of pretzels = 25 g
Recovery Nutrition…
 After exercise,
 Composition and timing of the recovery meal or snack
depend on the length and intensity of the exercise
session (ACSM, 2009).
 Glycogen
 Meals need to provide adequate fluids, electrolytes,
carbohydrates, and protein.
 A carbohydrate
Recovery Nutrition…
 The timing of
 The type of food is also significant because
consumption of high glycemic index CHOs results in
 Protein consumed after exercise provides amino acids
for building and repair of muscle tissue (ACSM, 2009).
Recovery Nutrition Summary
 Replace
 Can take 24 hours to fully reload
 Glycogen replacement is spurred post exercise
 Timing of meal less critical if 1-2 days rest are
 As
Sport Specific Guidelines
 Soccer/Basketball/Hockey/Lacrosse/ect..
 High energy demands
 Caloric
 Blood flow to the gut decreased (w/intensity)
 Higher CHO needs in-season/training
 Recovery critical with tournament play
 Replenish
 Prevents fatigue as season/training progresses
Dunford. M. (Ed). (2006) Sports Nutrition: A practice manual for professionals
Sport Specific Guidelines…
 Baseball
 Relatively low energy demands
 Prone to weight gain
 Skipped meals due to schedules
 Increased
 Dehydration
Sport Specific Guidelines…
 Football:
 Energy needs
 High
Sport Specific Guidelines
 Endurance Sp0rts:
 Uses the complete range of energy systems
 Fluid
 Primarily for the 2hr + events
 If using CHO gels – you need water too
 Snack frequently on high carb foods day before races
 Some
 Liberal sodium use, if needed
 ‘Practice’ eating habits before put to race day use
Dunford. M. (Ed). (2006) Sports Nutrition: A practice manual for professionals
Sport Specific Guidelines
 Endurance Sports:
 CHO loading guidelines:
 High
 You can
 One part glycogen to three parts stored water
 Protein also catabolized for energy
 1.5 g/kg/day recommendation
Clark N. (2003). Nancy Clark’s Sports Nutrition Guidelines
Sport Specific Guidelines…
 Swimming:
 High volume training programs are common
 Adjust intake to training season demands
 Fluid
 Organize
 Sports drinks,
 Multiple events = need recovery plan
Jeukendrup. A., (ed). (2010). Sports Nutrition: From lab to Kitchen, Meyer and Meyer Sport
Sport Specific Guidelines
Recreational athletes
Recovery meal timing likely not as crucial
Educate on caloric expenditure realities
 Prevents
 May require Fast food meal planning
 Activity:
 Identify the best menu choice for recovery from the
given menu for a 80 kg athlete
Recap: Menu Planning Across a
Spectrum of Training
 Examine
 Load up on the produce
 Minimum
 Maintain a good hydration plan
 ‘Practice’ new eating regimens before competing with
Nutrition Supplements…
 Supplement is
 A nutrition supplement cannot replace a healthy diet
Why Supplement?
 Gain a perceived ‘edge’
 Improve
 Change body composition
 Improve performance
 Supplement industry sales in 2011:
 Rate of growth of 7% annually
Dietary Supplement Health and
Education Act
 Passed in 1994
 Product is a…..
 Vitamin
 Mineral
 Herb or other botanical
 Amino acid
 Dietary substance
 Concentrate or metabolite of any of the above
Structure and Function claims…
 Strengthen
 Improve
 Protect
 defent
2002 International Olympic
Committee (IOC) Study
 94
 From 12 different countries
 U.S. supplements tested (45 of 240) had a 18.8% fail
Popular Sports Supplement
 Beta Alanine
 Non-essential amino acid
 Serves
 Acts as a buffering agent for lactic acid
 Supplementation
 Marketed to enhance weight training and high
intensity training
 Possibly effective – more research needed on safety
 Reported
 Caffeine
 Strongest
 CNS stimulant
 Decreased perception of effort
 In moderate doses is NOT a diuretic
 Amount
 Trial and error
 Approx 2 cups of coffee
 Caffeine
 Ganio et al (2009) found that abstaining from caffeine
at least 7 days before use will give the greatest chance
of optimizing the ergogenic effect
 Gliottoni et al (2009)
 Caffeine….not for everybody!
 monitor for side effects:
 Increased
 Nervousness
 GI problems
If not a regular user
High doses (>6 mg/kg)
 Creatine:
 Found in
 Helps to replenish ATP reserves in the muscles
 Provides energy via phosphagen system
 Increases rate of phosphocreatine systhesis
 Generally appears safe and effective
 Seems to
 ACSM recommends that it is NOT USED by children under
the age of 18
 Hydration needs to be addressed
 Pulls water into muscle cells
 Energy Drinks:
 Appeal to athletes
 Nutrient profiles vary
 25 grams of
 Consumed
 Caffeine and the herbal stimulant amounts are a
concern –
 Stresses heart rate and can lead to heat illness
The Color Code
 RED – Higher in saturated
fat and calories
 Use in moderation – these
can slow you down
 Yellow – a moderate
amount of fat and/or heavy
 Green – the leanest
selections of protein
and/or healthier a CHO
 High performance foods
 “Think about fuel and hydration as part of your
internal equipment. You can’t show up to practice and
be strong, be quick, and last long without pre-fueling.”
 Leslie Bonci, MPH, RD, CSSD, LDN
 Pittsburg Steelers