Download Nutrition in the Personal Training Setting

Nutritional Factors in Health
and Performance
Chapter 1O NSCA
Role of the Nutritionist
• Responsibilities of the nutritionist include
the following:
– Personalized nutritional counseling: weight
loss and weight gain, strategies to improve
performance, menu planning, dietary
supplements
– Dietary analysis of food records
– Nutritional education: presentations and
handouts
– Referral and treatment of eating disorders
Nutrition and Role of the Personal
Trainer
• It is well within the scope of
practice of the personal trainer
who possesses nutrition
knowledge to address
misinformation and to give advice
as it relates to general nutrition for
physical performance, disease
prevention, weight loss, and
weight gain
Nutrition and the Role of the Personal
Trainer
• From the standpoint of both ethics and safety,
referral to a nutrition professional is
indicated when the client has a disease
state (diabetes, eating disorder, heart
disease, GI disease, elevated cholesterol…)
that is affected by nutrition
• This type of nutrition information is called
medical nutrition therapy and falls under the
scope of a practicing licensed nutritionist or
registered dietician
• American Dietetic Association’s Web site:
www.eatright.org
Dietary Assessment
• Before the personal trainer can assess a
client’s diet they need to extract the following
information:
• What foods is the client allergic to?
• Is the client a vegetarian?
• Is he or she restricting food groups?
• Dieting to lose weight?
• Has the individual adopted a new way of
eating?
• How many meals does she or he eat a day and
at what time?
Dietary Assessment
• The personal trainer has
three methods of gathering
dietary intake data to
choose from:
– Dietary Recall
– Diet History
– Diet Records
Dietary Assessment
• Dietary Recall: client reports what they
have eaten in the past 24 hours
• Diet History has clients answering
questions about usual eating habits, likes
and dislikes, eating schedule, weight
history…
• Diet Record is a log filled out for three
days, in which the client records
everything consumed (foods, beverages
and supplements)
Dietary Assessment
• The Diet Record is considered the most
valid of the three methods for assessing
the diet of an individual
• The Diet Record is worth it only if the
client accurately and completely records
usual intake for three days
• To get useful data, the personal trainer
should only ask the most motivated
clients to complete this process
• At best, dietary analysis gives a general
idea of nutrient intake
How to Evaluate the Adequacy of the Diet
• Standard Nutrition Guidelines
– Food Guide Pyramid
• Used to evaluate appropriate calorie
level
• Used to evaluate appropriate nutrient
levels to prevent nutrient deficiency or
toxicity
• Developed by the U.S. Department of
Agriculture in 1992
• Updated to MyPyramid in 2005
How to Evaluate the Adequacy of the Diet
• Standard Nutrition Guidelines
–The color bands of MyPyramid
represent five food groups that are
needed each day for health:
• Grains
• Vegetables
• Fruits
• Milk
• Meat and beans
Figure 10.1
MyPyramid
• Excellent starting point from which to
evaluate the adequacy of a client’s diet
• If a diet provides a variety of foods from
each group, it is likely adequate for
vitamins and minerals. However, if the diet
excludes an entire food group, specific
nutrients may be lacking.
• For more information and resources,
go to www.mypyramid.gov
Energy
• Energy is commonly measured in
calories
• Three factors make up the energy
requirement of adults:
– Resting Metabolic Rate/Basal
Metabolic Rate
– Physical Activity
– Thermic Effect of Food
Resting Metabolic Rate
• The calories required to maintain normal
body functions such as respiration and
cardiac function
• Factors that increase RMR are lean body
tissue, young age, growth, abnormal body
temperature, menstrual cycle, and
hyperthyroidism
• Factors that decrease RMR are low
caloric intake, loss of lean tissue and
hypothyroidism
Energy
• The amount of energy needed for
physical activity depends on the
intensity, duration, and frequency
of training
• Thermic effect of food is the
energy needed to digest and
assimilate food
Weight and Body Composition
• Energy Requirements
–Estimating Energy Requirements
• Energy needs can be loosely
estimated using the guidelines
found in table 10.7
• Clients can also use food diaries
during periods of stable body
weight to estimate requirements
Weight and Body Composition
• Weight Gain
–If all the extra calories consumed
are used for muscle growth
during resistance training, then
about 2,500 extra kilocalories
are required for each 1-pound
(0.45 kg) increase in lean tissue
Weight and Body Composition
• Weight Loss
– If all the expended or dietary-restricted
kilocalories apply to body fat loss, then a
deficit of 3,500 kcal will result in a 1pound (0.45 kg) fat loss
– The maximal rate of fat loss appears to be
approximately 1% of body mass per week
– This is an average of 1.1 to 2.2 pounds (0.51.0 kg) per week and represents a daily
caloric deficit of approximately 500 to 1,000
kcal.
Weight Gain Versus Weight Loss
• Gains in body mass and strength occur
when the client consumes adequate calories
and dietary protein and engages in a
progressive resistance training program.
• The most important goal for weight loss
is to achieve a negative calorie balance.
• The types of foods the individual consumes
are less important than the portions of
those foods
• The focus is on calories
Weight and Body Composition
• Rapid Weight Loss
–For clients who desire to
minimize lean tissue loss,
small decreases in caloric
intake to achieve gradual
weight loss are indicated
Protein
• General Requirements
–Assuming that caloric intake is
adequate and that two-thirds or
more of the protein is from animal
sources, the recommended intake
for protein for adults is 0.8 g/kg
(0.36 g/pound) of body weight for
both men and women.
–Expressed as a percent of daily
caloric intake, a common protein
intake recommendation is 10% to
15%
Protein
• Increased Requirements for
Athletes
–Based on current research, it
appears that the protein
requirements for athletes are
between 1.5 and 2.0 g/kg (more
than 2.0 g/kg if you are
vegan/vegetarian) of body
weight, assuming that caloric
intake and protein quality are
adequate
Key Point
• Recommendations to increase or
decrease protein intake should be made
on an individual basis after the normal diet
has been analyzed and caloric intake
considered.
• A mixed diet is the best source of highquality protein.
• Strict vegetarians must plan their diet
carefully to ensure an adequate intake of
all essential amino acids.
Carbohydrates
• The primary role of carbohydrate in
human physiology is to serve as an
energy source.
–Provide 4 kcal/g
– 50 to 100 grams (the equivalent of 3 to 5
pieces of bread) are needed to prevent
ketosis
• Ketosis: incomplete metabolism of fatty
acids. Ketosis occurs in diabetic patients
or when not enough carbohydrates are
eaten.
Carbohydrate Requirements
• A general recommendation is 8 to 10 g/kg of BW
for aerobic endurance athletes (90 minutes or
more daily)
• Intake of 5-6g/kg of BW is recommended if not
training aerobically (90 minutes or more a day)
• Fiber
• There is no nutritional value for fiber
• The DRI for fiber is 38 and 25 g/day for young
men and women, respectively.
• This level of fiber may be excessive for some
aerobic endurance athletes.
Glycemic Index
• The GI classifies a food by how high and for
how long it raises blood glucose.
• The reference food is glucose or white bread
(GI = 100).
• Foods that are digested quickly and raise
blood glucose (and insulin) rapidly have a
high GI.
• Foods that take longer to digest and thus
slowly increase blood glucose (and therefore
stimulate less insulin) have a low GI.
Key Point
• Some aerobic endurance athletes
have maximal carbohydrate
requirements, up to 10 g/kg per day.
• Most athletes do not deplete muscle
glycogen on a daily basis, however,
and therefore have lower
carbohydrate requirements.
Fat (Lipids)
• Fat and Performance
– Intramuscular fatty acids are more
important during activity
– Circulating fatty acids (from adipose tissue
or diet) are more important during recovery
– Consumption of high-fat diets may
enhance performance and result in longer
distance to exhaustion
– The effects of high-fat diets vary,
depending on the individual
Fat (Lipids)
• A source of energy (9 calories per gram)
– Fat Requirements and Recommendations
• The recommendation for the general public
from health organizations such as the
American Heart Association is that fat should
constitute 30% or less of the total calories
consumed.
• It is recommended that 20% of the total
calories (or two-thirds of the total fat intake)
come from monounsaturated or
polyunsaturated sources and 10% from
saturated fats (one-third of total fat intake).
Fat (Lipids)
• The Sub-Committee on Nutrition of the
United Nations recommends an upper
limit for fat intake of 35% of total calories
for active people.
• The American Heart Association and the
Sub-Committee on Nutrition of the United
Nations recommend that fat provide at
least 15% of the total calories in the diets
of adults and at least 20% of total calories
in the diets of women of reproductive age.
When Should Athletes Decrease Dietary Fat?
• Need to increase carbohydrate intake to support training
type
– In this case, to ensure adequate protein provision, fat
is the nutrient of choice to decrease so that that
caloric intake can remain similar while carbohydrate is
increased.
• Need to reduce total caloric intake to achieve weight
loss
– Because fat is dense in calories and is highly
palatable, decreasing dietary fat, if the diet has
excess fat, can help reduce caloric intake.
• Need to decrease elevated blood cholesterol
– Some young athletes are strongly predisposed to
heart disease, although this is uncommon.
Micronutrients
• A micronutrient is a nutrient that is
required in small amounts (typically
measured in milligram—or even
smaller—quantities) in the diet
• Two primary types of micronutrients
are vitamins and minerals
Vitamins and Minerals
• Minerals
• Vitamins
– Vitamins are
– Minerals are
organic substances
required for a wide
(i.e., containing
variety of metabolic
carbon atoms) that
functions.
cannot be
– For athletes,
synthesized by the
minerals are
body.
important for bone
– They are needed in
health, oxygenvery small amounts
carrying capacity,
and perform
specific metabolic
and fluid and
functions.
electrolyte balance.
Precompetition and Postexercise Nutrition
• Precompetition Food Consumption
– Purpose
• The primary purpose is to provide fluid and
energy for the athlete during the
performance.
– Timing
• The most common recommendation is to
eat 3 to 4 hours prior to the event to
avoid becoming nauseated or
uncomfortable during competition.
Precompetition and Postexercise Nutrition
• Carbohydrate Loading: technique used to
enhance muscle glycogen prior to long-term
aerobic endurance training
• Eating 3 days of a high carbohydrate diet with
tapering of exercise the week before
competition
• 600 grams of CHO’s per day or 8-10 g per kg of
body weight
• This should increase muscle glycogen stores
20-40% above normal
Precompetition and Postexercise Nutrition
• Consume carbohydrates immediately
after exercise
• Consume moderate to high glycemic
index carbohydrate-containing foods
(50-75 g of carbohydrate each hour)
• With optimum carbohydrate intake,
glycogen stores replenish at a rate of
about 5 to 7% per hour
Precompetition and Postexercise Nutrition
• Postexercise Food Consumption
– Data suggest that high-GI foods consumed
after exercise replenish glycogen faster than
low-GI foods
– Although emphasis is usually placed on
carbohydrate, in practical terms, consuming a
balanced meal ensures the availability of all
substrates for adequate recovery, including
amino acids.
Fluid and Electrolytes
• Water
–Water is the largest component of the
body, representing from 45% to 70% of
a person’s body weight.
–Total body water is determined largely
by body composition; muscle tissue is
approximately 75% water, whereas fat
tissue is about 20% water.
Fluid and Electrolytes
• Water
–Fluid Balance
• The average fluid requirement for
adults is estimated to be 2 to 2.7
quarts (1.9-2.6 L) per day
• Athletes sweating profusely for
several hours per day may need to
consume an extra 3 to 4 gallons (1115 L) of fluid to replace losses
Water Recommendations
• The basic goal of fluid intake is to
avoid dehydration
• Dehydration is a state in which the
body tissues are deprived of water. It
can occur when the blood sugar
levels are high for long periods of
time. It can also result from
inadequate water intake, or excessive
sweating, vomiting or diarrhea.
• No one adapts to dehydration
Dehydration
• 1% of fluid loss= Elevated Core
Temperature
– Treatment involves rest in a cool shaded area
and drinking mildy salted fluid.
• 3-5% of Fluid Loss= Heat Exhaustion
– The Cardiovascular system is unable to
pump sufficient blood to meet all of the
body’s needs and inability to dissipate heat.
• At 7% loss= Heat Stroke
– Profuse sweating, rubbery legs, chills, slight
confusion, nausea, vomitting, rapid and weak
pulse, collapse likely
Signs of Dehydration
• Thirst
• Irritability
•Muscle cramps
•Chills
• Fatigue
• General
discomfort
• Headache
• Weakness
• Dizziness
•Vomiting/nausea
•Head or neck heat
sensations
•Decreased
performance
Types of Fluid
• The ideal beverage may not be plain
water
• Beverage should replace sweat lost
during physical activity and contain:
– Water for hydration
– Carbohydrate to speed absorption of fluid
and begin refueling muscles
– Electrolytes to speed rehydration
When Sports Drinks are Better Than Water
• During intense exercise
• During exercise that lasts longer
than 45-50 minutes
• During training that occurs multiple
times throughout the day
• When regular meals are not available
• Anytime a sport or activity is competitive
Casa, DJ, et al. NATA Position Statement: Fluid Replacement For Athletes. Journal of
Athletic Training. 2000;35(2):212-224.
Benefits of Sports Drinks
• Sodium
– May increase water retention (less urine)
– Sodium activates thirst mechanism
( voluntary rehydration)
– Decrease risk of hyponatremia
– Decrease risk of muscle cramps
– Most importantly, it replaces sodium lost in
sweat and helps maintain fluid homeostasis
Casa, DJ, et al. NATA Position Statement: Fluid Replacement For Athletes.
Journal of Athletic Training. 2000;35(2):212-224.
Fluids to Avoid During Exercise
• Diuretics are drugs that help get rid of water and
salt and promote urination
– Caffeinated beverages
– Alcohol
– Carbonated beverages (GI distress)
– Herbal Caffeine Supplements
– Guarana
– Kola Nut
– Herbal Diuretics
– St. John’s Wort
– Ephedra
How Do You Monitor Fluid Balance?
• Go Pee!
• Each pound (0.45 kg) lost during
activity represents 1 pint
(16 ounces or 2 cups) of fluid loss
• Signs of dehydration include the
following:
–Dark yellow, strong-smelling urine
–Decreased frequency of urination
–Rapid resting heart rate
–Prolonged muscle soreness
Fluid and Electrolytes
• Electrolytes
–The major electrolytes lost in sweat are
sodium chloride, and, to a lesser
extent, potassium
• Fluid Replacement
–The ultimate goal is to start exercise in a
hydrated state, avoid dehydration during
exercise, and rehydrate before the next
training session
Key Point
• Consuming adequate fluids
before, during, and after training
and competition is essential to
optimal resistance training
and aerobic endurance exercise
Fluid Replacement Guidelines
• Before a Training Session
–Encourage athletes/clients to
hydrate properly before
prolonged exercise in a hot
environment.
–Intake should be approximately
16 fluid ounces (2 cups) of a
cool beverage 2 hours before
a workout
Fluid Replacement Guidelines
• During a Training Session
– Provide cool beverages (about 50-70 °F [1021 °C]).
– Have fluids readily available, since the thirst
mechanism does not function adequately
when large volumes of water are lost
– Athletes need to be reminded to drink
– Athletes should drink fluid frequently—for
example, 6 to 8 fluid ounces (about a cup)
every 15 minutes
Fluid Replacement Guidelines
• After a Training Session
– Athletes should replenish fluids with at least
1 pint (16 oz or 2 cups) of fluid for every
pound (0.45 kg) of body weight lost
– Weight should be regained before the next
workout
– Water is an ideal fluid replacement, although
flavored beverages may be more effective at
promoting drinking
– The ideal fluid replacement beverage depends
on the duration and intensity of exercise,
environmental temperature, and the athlete
Fluid Replacement Guideline Summary
1 cup © = 8 fluid oz (fl oz)
1 pint (pt) = 2 cups = 16 fluid oz
1 liter (L) = 2 pints = 4 cups = 32 fl oz
• 2 hours before a workout: 16 fl oz.
• During exercise: 6-8 fl oz. every 15
minutes
• After exercise: 1 pt (.5 L) for every pound
(.45 kg) of body weight lost
Heat Index
• The heat index is an accurate measure of how
hot it feels (in degrees) when moisture (relative
humidity) is added to the actual air pressure
• On this scale, high humidity can make you
excruciatingly hot because your body has no
way to eliminate excess heat.
• For example, 100 degrees F with 100-percent
humidity is the equivalent of 195 degrees F at
25-percent humidity -- nearly the boiling point of
water!
Heat Index
• Dehydration, heat exhaustion and heat stroke can
occur faster if you perform outdoor activities
• Evaporative cooling works great if the air is dry. In
high humidity, however, it doesn't work very well.
The sweat cannot evaporate because the air is
already saturated with humidity.
• In high temperature/high humidity environments,
your body can get into a dangerous situation
where it cannot radiate or evaporate the heat
away.
• The heat index that you see on the evening news
is designed to make you are aware of these
dangerous situations
Heat Illnesses
• Heat Cramps
• Heat Exhaustion
• Heat Stroke
• Hyponatremia
Heat Related Muscle Cramps
• Symptoms
– Muscle spasms (Calf, Hamstrings, Abdomen)
– Occasionally Whole Body Cramps
– Muscle pain
Athletes Prone To Getting Heat
Cramps
• History of heat cramps
•
•
•
•
Eats a low-salt diet
Sweats early and heavy
Poor hydration habits
Excessive sodium losses
through sweat
• Not acclimated to
heat/humidity
Treating Muscle Cramps
•
•
•
•
•
Mild Stretching
Ice Massage
Rest
Fluid replacement
Additional sodium
Heat Exhaustion
• Heat Exhaustion: 3-5% of
Fluid Loss
• The Cardiovascular system
is unable to pump sufficient
blood to meet all of the
body’s needs
Heat Exhaustion
• Signs and
Symptoms: profuse
sweating, rubbery
legs, chills, slight
confusion, nausea,
vomiting, rapid and
weak pulse,
excessive fatigue,
pale or flushed
skin, impaired
ability to dissipate
heat
Heat Exhaustion
• Treatment: Rest in
a cool
environment,
elevation of legs,
pouring of cool
water on the skin,
replacement of
fluids orally or IV.
Recovery within
12-48 hours
Heat Stroke
• Heatstroke is 7% loss
of fluid
• Failure of the
cardiovascular
system during
exercise in a hot
environment
• Extreme
hyperthermia: core
body temp above 104
Farenheit
• Medical Emergency
Heat Stroke
• Symptoms
– Weakness
– Irrational behavior
– Drowsiness
– Confusion
– Disorientation
– Dizziness
– Nausea
– Rectal temperature >104 F
– Hypotension (systolic <90 mm Hg)
– Hot Dry skin
– Collapse
Emergency Management of Heat
Stroke
• Seek medical attention
immediately!
• Cool the body down before
moving an athlete using:
• An ice bath (preferred)
• Ice packs placed at
the groin, neck and
armpits
• A cool shower
• Wet towels
• Water spray
Heat Illness Video
• http://www.youtube.com/watch?v=ESauS6
1OHFg&feature=related
High Profile Heat Related Deaths
• Korey Stringer
–Minnesota
Vikings
–27 years old
–335 pounds
–Collapsed of
heatstroke during
fall camp; died 15
hours later
High Profile Heat Related Deaths
• Eraste Autin
– University of Florida
freshman fullback
– 6’2”, 250 pounds
– 88 degrees, 72%
humidity on the day
he collapsed during a
routine training
session
– Core temp > 108
degrees
Hyponatremia
• Excessive sweating plus ingesting large
volumes of plain water during prolonged
exercise sets the stage for hyponatremia
(water intoxication) caused by a decrease
in extracellular sodium concentration.
• Drinking too much water results In Low
blood sodium (<135 mEq/L)
Hyponatremia
• Symptoms
–Early: Headache, apathy,
fatigue, nausea and possibly
cramping
–Advanced: Confusion, lack of
coordination, seizure, coma,
collapse and death
Hyponatremia
• Prevention
–Eat salty foods and snacks
–Drink fluids containing electrolytes
–Avoid drinking only water
Treatment
–Seek medical attention immediately!
Glucose, Electrolytes, and Water
Uptake
• Large fluid intake may inhibit carbohydrate
uptake
• Concentrated sugar solutions may impair
fluid replacement
• Carbohydrate-containing solutions
consumed during exercise enhance
endurance performance by maintaining
blood sugar concentration
Glucose, Electrolytes, and Water
Uptake
• Glucose supplied in the blood can
spare existing glycogen in active
muscles
• The ideal hydration solution contains
between 4-8% carbohydrates
• Adding moderate amounts of sodium
to the ingested fluid helps to maintain
plasma sodium concentration