Introduction… Research shows that, regardless of the sport, an athlete’s diet plays a critical,...
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Nutritional Considerations
Introduction… Research shows that, regardless of the sport, an athlete’s diet plays a critical, if not essential, role in performance. Yet misinformation
Introduction Research shows that, regardless of the sport, an
athletes 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.
Slide 3
Introduction 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
athletes 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
Slide 4
A brief history of sports nutrition Specific text on the diet
of ancient athletes are rare. Human muscle energy metabolism began
to be studied in the late 19 th century
Slide 5
Milo of Croton 6 th 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
Slide 6
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
Slide 7
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
Slide 8
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
dont 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
Slide 9
He first used Gatorade on guinea pigs(who were the JV squad)
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
Slide 10
Introduction Proper nutritional knowledge is imperative for all
individuals, but especially for those involved in athletic
competitions (Jacobson, Sobonya, & Ransone, 2001). An athletes
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.
Slide 11
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
magazines. 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.
Slide 12
Nutrients: An Overview According to the American Dietetic
Association (2009), eating correctly for sports performance will 1.
Help the athlete train longer and at a higher intensity 2. Delay
the onset of fatigue 3. Promote recovery 4. Help the athletes body
adapt to workouts 5. Improve body composition and strength 6.
Enhance concentration 7. Help maintain healthy immune function 8.
Reduce the chance of injury 9. Reduce the risk of heat cramps and
stomachaches
Slide 13
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).
Slide 14
Carbohydrates Carbohydrates (CHO) are molecules that, by way of
their metabolic breakdown, provide energy for high- intensity
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.
Slide 15
Carbohydrates 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.
Slide 16
Carbohydrates 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).
Slide 17
Carbohydrates Monosaccharides *Single molecule *fructose,
glucose, and galactose Disaccharides *two monosaccharide molecules
*lactose, sucrose, maltose Polysaccharides *10 to thousands of
monosaccharides linked together *glycogen, starch, cellulose
Slide 18
Carbohydrates 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).
Slide 19
Carbohydrates 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.
Slide 20
Carbohydrates 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).
Slide 21
Carbohydrates 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).
Slide 22
Carbohydrates 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.
Slide 23
Carbohydrates 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.
Slide 24
Carbohydrates 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.
Slide 25
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).
Slide 26
Carbohydrates 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.
Slide 27
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 glycogen. Physiologically, it is to the athletes
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.
Slide 28
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.
Slide 29
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.
Slide 30
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.
Slide 31
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)
http://www.youtube.com/watch?v=heQ5eukh8t8
Slide 32
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)
Slide 33
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. Fatigue = when exercise
continues to the point that compromises liver and muscle glycogen
supply. 2 hour strenuous workout can deplete liver and muscle
glycogen. (Jon Vredenburg, MBA, RD, CSSD, LD/N, HFS)
Slide 34
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 calories/hour.
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
Slide 35
Where the fuel could be used Blood Glucose Liver Storage Fat
storage Energy for tissues Muscle Storage *Brain storage has 20% at
rest
Slide 36
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.
Slide 37
Fat (Lipids) Depending on their molecular structure, fats can
exist either in liquid (oils) or solid form. Simple fats consist of
two compounds: Glycerol Fatty acid Can be either saturated or
unsaturated
Slide 38
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 atom. 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
temperature.
Slide 39
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
polyunsaturated.
Slide 40
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 atoms
Slide 41
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.
Slide 42
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.
Slide 43
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 time. 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.
Slide 44
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.
Slide 45
Fat and Exercise Potentially unlimited source of fuel during
aerobic exercise. 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.
Slide 46
Fat burning, simplified Fatty acids broken down in the
mitochondria generate Acetyl CoA entry in the Krebs (TCA) cycle.
Accumulation of Acetyl CoA occurs in absence of carbohydrate.
Physical activity becomes compromised Carbohydrate substrates
needed to sustain Krebs Cycle Fat burns in a carbohydrate
flame
Slide 47
Protein 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 molecules. The majority of the bodys 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
Slide 48
Protein 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 activity. Research suggests
that a regimen of regular aerobic exercise enhances the bodys
ability to generate energy from the metabolism of proteins (Sumida
& Donovan, 1995).
Slide 49
Protein 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 bodys proteins, 8 cannot be
synthesized by the body and must, therefore, be ingested in the
diet.
Slide 50
Protein 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.
Slide 51
Protein They include foods found in the legume and grain
categories. 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.
Slide 52
Protein Substance in foods made up of chains of amino acids
(AA) Three categories of AA: Essential Nonessential Conditional
Build, repair and maintain body tissues Provide energy if carbs and
fats are in short supply 4 calories per gram
Slide 53
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.
Slide 54
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.
Slide 55
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 orally.
Unfortunately, because these products are marketed as food
supplements, their purity is not monitored by the Food and Drug
Administration.
Slide 56
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 products.
http://www.youtube.com/watch?v=ZRgZuS_U9TQ
Slide 57
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 high- protein foods or special
preparations of amino acids (McArdle et al., 2009).
Slide 58
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 day. 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
Slide 59
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).
Slide 60
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
Slide 61
Vitamins 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).
Slide 62
Vitamins Vitamins contain no caloric value and, as such, do not
directly provide energy for muscle contraction.
Slide 63
Vitamins So far, 13 specific vitamins have been identified and
are divided into two groups: Water soluble Fat soluble
Slide 64
Vitamins Water-Soluble group includes: Vitamin C (ascorbic
acid) The B vitamins B1, B2, B6, B12 Niacin Folic acid Biotin
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.
Slide 65
Vitamins 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., 2009).
Slide 66
Vitamins 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 RDAs 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.
Slide 67
Vitamins To be effective, vitamins should be taken after meals
to optimize absorption because they work best in the presence of
other nutrients.
Slide 68
Vitamins Key regulators in energy metabolism Offer protection
against oxidative damage Supports growth and development If take
too many may have a reverse effect
Slide 69
Minerals 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.,
2009). 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.
Slide 70
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.
Slide 71
Minerals 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).
Slide 72
Minerals 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.
Slide 73
Minerals 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.
Slide 74
Minerals 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.
Slide 75
Minerals 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.
Slide 76
Minerals 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 problems. The recommended daily
dosage for adolescent females is 1500 mg.
Slide 77
Minerals 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 tissue Control acid-base balance
Slide 78
Water 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.
Slide 79
Water Housed in two general locations: Are extracellular fluids
Those. Intracellular fluids Those. Water is constantly being lost
through normal body functions.
Slide 80
Water 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,.
Slide 81
Water 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.
Slide 82
Water To calculate the reduction in body weight due to fluid
loss,. 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).
Slide 83
WaterSummary 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
Slide 84
Water..Summary 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
Slide 85
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
Slide 86
Sweat Mineral Composition Sodium460-1840 mg/L Chloride710-2840
mg/L Potassium160-390 mg/L Magnesium0-36 mg/L Calcium0-120 mg/L
Dunford. M. (Ed). (2006) Sports Nutrition: A practice mineral for
professionals
Slide 87
Hydration Guidelines Before exercise: During exercise: After
exercise: Source: American College of Sports Medicine.
www.acsm.org
Slide 88
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
Slide 89
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
damage.
Slide 90
Sports Drinks The Cool and non-carbonated Sodium Provides the
drive to drink; maintains proper sodium balance CHO At
concentrations High CHO content leads to GI distress Multiple
Maltodextrins used to enhance palatability (less sweat)
Slide 91
Sports Drink vs. Water Water As intensity and duration increase
sports drinks are preferred Exogenous energy source aids
performance
Slide 92
Sweat Rate Amount of sweat lost in an hour Determine
pre-exercise weight Determine activity 16 oz = 1 pound Determine
post-exercise weight Provides individualized guidance Sweat
Rate
Slide 93
Rehydration Helps Under-hydration Rehydrate with an amount
greater than the losses
Slide 94
Special Considerations.. Female Athletes As more women become
involved in organized sports, concerns. 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.
Slide 95
Special Considerations.. Female Athletes Loosli and Benson
(1990) surveyed 76 adolescent female gymnast and their results
indicate that.
Slide 96
Special Considerations.. Female Athletes Because gymnastics
place great emphasis on being lean,. However, gymnastics is not
alone. It was also reported that 47% of athletes in lean.
Slide 97
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.
Slide 98
Wrestling 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 dehydration.
Slide 99
Wrestling 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.
Slide 100
Wrestling 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.
Slide 101
Wrestling 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.
Slide 102
Conclusions 1. 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..
Slide 103
Conclusions 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
Slide 104
Conclusions 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
calories..
Slide 105
Conclusions Athletes tend to consume too many calories in the
form of junk food, which is laden with fat and extra protein. Many
athletes diets are deficient in at least some important minerals,
such as calcium, iron, and zinc. However, the. (McArdle et al.,
2009).
Slide 106
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)
Slide 107
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
Slide 108
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 ATP
McArdle W., Katch F & Katch V (2005) Sport & Exercise
Nutrition
Slide 109
Aerobic System After With oxygen present, gerater yield of ATP
Fuel sources with aerobic respiration Muscle glycogen Liver
glycogen Exogenous fuel Fatty acids, (proteins) McArdle W., Katch F
& Katch V (2005) Sport & Exercise Nutrition
Slide 110
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
Slide 111
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)
Slide 112
Additional Tips Feature Add energy dense foods to the diet
Stack foods with add-ons Potato with toppings Dried fruit and nuts
on cereal Dont drink water right before meals Monitor caffeine to
promote rest Content adapted from: Litt, A (2004) Fuel for Young
Athletes
Slide 113
Adding energy dense foods Choose ThisCaloriesOver ThisCalories
Cup of Granola500Cup of cheerios90 Bag of Peanuts170Bag of
pretzels110 Sandwich on a sub Roll500sandwich on bread300 Bagel
330english muffin130 Sports Drink 20 oz135water0
Slide 114
Mistakes Commonly Made These 1. Over-eat protein 2. Under-eat
carbohydrates 3. No dietary variation
Slide 115
Safe Weight Loss Best Look at Common recommendation: 1-2 pound
per week decrease Larger Greater number and volume of adipose
cells
Slide 116
Are there bad foods? General rule of thumb: The less processed
it is, the better nutritional benefits you will receive.
Slide 117
Menu Planning Fueled Pre-exercise meals Give ample time for
digestion Provide the correct fuel matrix CHO, Minimize potential
GI stressors Stress food safety Know their tastes Know your
budget
Slide 118
Menu Planning Early events Top Try AND light snack the morning
of even (1-2 hrs. before)
Slide 119
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
Slide 120
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
Slide 121
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.
Slide 122
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).
Slide 123
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 upcoming As
Slide 124
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
Slide 125
Sport Specific Guidelines Baseball Relatively low energy
demands Prone to weight gain Skipped meals due to schedules
Increased Dehydration
Slide 126
Sport Specific Guidelines Football: Energy needs High
Slide 127
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
Slide 128
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 Clarks Sports Nutrition
Guidelines
Slide 129
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
Slide 130
Sport Specific Guidelines Recreational athletes Educate
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
Slide 131
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 them
Slide 132
Nutrition Supplements Supplement is A nutrition supplement
cannot replace a healthy diet
Slide 133
Why Supplement? Gain a perceived edge Improve Change body
composition Improve performance Supplement industry sales in 2011:
Rate of growth of 7% annually
Slide 134
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
Slide 135
Structure and Function claims . Strengthen Improve Protect
defent
Slide 136
2002 International Olympic Committee (IOC) Study 94 From 12
different countries U.S. supplements tested (45 of 240) had a 18.8%
fail rate
Slide 137
Popular Sports Supplement Review 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
Slide 138
Caffeine Strongest CNS stimulant Decreased perception of effort
In moderate doses is NOT a diuretic Amount Trial and error Approx 2
cups of coffee
Slide 139
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)
Slide 140
Caffeine.not for everybody! monitor for side effects: Increased
Nervousness GI problems If not a regular user High doses (>6
mg/kg).
Slide 141
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
Slide 142
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
Slide 143
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 processed Green the leanest selections of protein
and/or healthier a CHO High performance foods
Slide 144
CONCLUSION Think about fuel and hydration as part of your
internal equipment. You cant show up to practice and be strong, be
quick, and last long without pre-fueling. Leslie Bonci, MPH, RD,
CSSD, LDN Pittsburg Steelers