Physical Activity, Nutrients, and Body Adaptations
FITNESS
FITNESS

Fitness involves physical activity or exercise.

The components of fitness are cardiorespiratory
endurance, flexibility, muscle strength, and muscle
endurance.

All of these characteristics describe a healthy body.

Today’s world encourages sedentary lifestyles (boo!)
that foster the development of several chronic
diseases. [Then you die]
FITNESS


Benefits of Fitness





Restful sleep
Nutritional health
Optimal body
composition
Optimal bone density
Resistance to colds
and other infectious
diseases






Lower risks of some types of
cancer
Strong circulation and lung
function
Lower risk of cardiovascular
disease
Lower risk of type 2 diabetes
Reduced risk of gallbladder
disease in women
Lower incidence and severity of
anxiety and depression
Long life and high quality of life
in the later years
FITNESS



The 2005 Dietary Guidelines for
Americans state that people need to
participate in
30 minutes of physical activity most
days of the week for health benefits
and
60 minutes of physical activity most
days of the week to maintain a
healthy body weight.
THE 100-METER MOSEY
THOUGHT OF THE DAY
Before you criticize
someone, you should walk
a mile in their shoes.
That way, when you
criticize them, you're a
mile away and you have
their shoes
FITNESS
 Developing
Fitness
 Guidelines
for conditioning that are achieved
through training.
Cardiorespiratory
Endurance
Frequency – 3-5 days per week
Intensity
– 55-90% maximum heart rate
Time/Duration
– 20-60 minutes
FITNESS

Guidelines for conditioning
 Strength
Frequency
Intensity
– 2-3 days per week
– enough to enhance muscle strength,
muscle endurance, and improve body
composition
Time/Duration – 8 to 12 repetitions of 8 to 10
different exercises
Well keep
looking, keep
looking!
FITNESS

Guidelines for conditioning
 Flexibility
Frequency
Intensity
– 2-3 days per week
– enough to develop and maintain a full
range of motion
Time/Duration – 4 repetitions of 10-30 seconds
per muscle group
FITNESS

Developing Fitness
 The
Overload Principle – to slightly increase
comfortable capacity in each area.
Also called the progressive overload principle.
 Increase
frequency – how often an activity is performed
 Increase intensity – the degree of exertion while exercising
 Increase time/duration – the length of time
FITNESS

Developing Fitness

The Body’s Response to Physical Activity
 Hypertrophy is muscle gain in size and strength, the result of
repeated work.
 Atrophy is muscle loss in size and strength, the result of lack of
activity.
 Other Tips







Be active all week.
Use proper equipment and attire.
Use proper form when exercising.
Include warm-ups and cool-downs.
Challenge yourself, but not every time you exercise.
Pay attention to body signals.
Build intensity slowly.
Seven days without exercise
makes one weak!
FITNESS

Developing Fitness
 Cautions
on Starting
 Healthy
people can start with a moderate exercise
program without seeking medical advise first.
 People
with risk factors may need medical advice.
FITNESS

Cardiorespiratory Endurance
 Cardiorespiratory
conditioning is measured by
maximum oxygen uptake (VO2max).
 Increases
cardiac output and oxygen delivery
 Increases stroke volume
 Slows resting pulse
 Increases breathing efficiency
 Improves circulation
 Reduces blood pressure
To prevent a heart attack, take one aspirin every day.
Take it for a walk, then take it to the gym,
Then take it for a bike ride
FITNESS

Cardiorespiratory Endurance

Muscle Conditioning
Muscles use oxygen efficiently.
 Muscles can burn fat longer.


A Balanced Fitness Program
Individualized
 Cardiorespiratory
 Muscle strength and endurance
 Flexibility
 Choose an activity you enjoy

FITNESS

Weight Training
 Also
called resistance training
 Increases muscle strength and endurance
 Prevents and manages cardiovascular disease
 Enhances psychological well-being
 Maximizes and maintains bone mass
 Enhances performance in other sports
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

The Energy Systems of Physical Activity—ATP and CP

ATP is adenosine triphosphate – a high-energy compound
that delivers energy instantaneously.

CP is creatine phosphate – a high-energy compound in
the muscles, used anaerobically.

The Energy-Yielding Nutrients
Nutrients work together while one may predominate.
 Depends on diet, intensity and duration of the activity, and
training

ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Extremely intense activity





8-10 seconds
ATP-CP (immediately available)
No oxygen needed (anaerobic)
Activity example – 100 yard dash, shot put
Very highly intense activity




20 seconds to 3 minutes
ATP from carbohydrate (lactic acid)
No oxygen needed (anaerobic)
Activity example – ¼ mile run at maximum speed
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Highly intense activity





3-20 minutes
ATP from carbohydrate
Oxygen needed (aerobic)
Activity example – cycling, swimming, running
Moderately intense activity




More than 20 minutes
ATP from fat
Oxygen needed (aerobic)
Activity example – hiking
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Glucose Use during Physical Activity
 Diet
Affects Glycogen Storage and Use
 High-carbohydrate
diets increase glycogen stores
 Enhance endurance
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY
 Intensity
of Activity Affects Glycogen Use
Moderate activities use glycogen slowly.
Intense
activities use glycogen quickly.
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Glucose Use during Physical Activity

Lactate
Low intensity activities can clear lactic acid from the blood.
 During highly intense activities lactic acid accumulates and activity
can only be maintained for 1-3 minutes.
 Lactate is converted to glucose in the liver (Cori cycle).


Duration of Activity Affects Glycogen Use
 First 20 minutes – primarily use glycogen

After 20 minutes – use glycogen and fat
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Glucose Use during Physical Activity


“Hitting the wall” – exhaustion of glucose stores
Maximizing Glucose Supply
 High-carbohydrate diet – 8 g/kg body weight or 70% of
total energy intake
 Glucose
during activities if activity last longer than 45
minutes (sports drinks, diluted fruit juice)
 Eat
approximately 60 g of high-carbohydrate foods after
activity.
 Carbohydrate
loading is a regime of diet and exercise that
maximizes glycogen storage. It is also called glycogen
loading or glycogen super compensation.
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Glucose Use during Physical Activity
 Glucose
during Activity
 Activities
lasting longer than 45 minutes
 Light carbohydrate snacks under 200 kcalories
 Glucose
after Activity
 High-carbohydrate
meal within 15 minutes accelerates
glycogen storage by 300%
 High-carbohydrate meal within 2 hours and rate of
glycogen storage declines by half
 High-glycemic index foods
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Glucose Use during Physical Activity
 Training
Affects Glycogen Use
 Muscles
that repeatedly deplete glycogen through hard
work will store greater amounts of glycogen.
 Conditioned
for energy.
muscles rely less on glycogen and more on fat
 Trained
muscle cells have more mitochondria and can use
oxygen better.
 Untrained
pathways.
muscle cells depend more heavily on anaerobic
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fat Use during Physical Activity
 Duration
of Activity Affects Fat Use
 Beginning
of activity uses fatty acids in the blood
 After 20 minutes, uses body fat as major fuel
 Intensity
 As
of Activity Affects Fat Use
intensity increases, fat makes less of a contribution to
the fuel mix
 Oxygen must be abundant to break down fat
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fat Use during Physical Activity
 Training
 The
Affects Fat Use
better trained the muscles, the more fat is used
 The
better trained, the stronger the heart and lung to
deliver oxygen
 If
better trained, then hormones prevent glucose release
from the liver, so they rely more on fat
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Protein Use during Physical Activity—and between
Times

Protein Used in Muscle Building
 Synthesis of protein is suppressed during activity.
 After activity protein synthesis accelerates.
 Repeated activities cause body adaptations to support
needs.
 Remodeling
 Daily, ¼ to 1 ounce of body protein is added to muscle
mass during muscle-building phase.
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Protein Use during Physical Activity—and between
Times

Protein Used as Fuel
During physical activity muscles use amino acids for fuel.
 10% of total fuel used


Diet Affects Protein Use during Activity
Diets rich in energy and carbohydrate allow the body to use less
protein for fuel.
 Carbohydrates spare protein.

ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Protein Use during Physical Activity—and between
Times

Intensity and Duration of Activity Affect Protein Use during
Activity
If glycogen stores get depleted, then more reliance on protein
 Anaerobic strength training demands more protein to build muscles
but not large amounts.


Training Affects Protein Use

The more trained the less protein used for energy
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Protein Use during Physical Activity—and between
Times

Protein Recommendations for Active People
Athletes in training need more protein than sedentary people.
 Athletes in training need to meet energy and carbohydrate needs
first.
 Adult RDA: for males 56 g/day, for females 44 g/day
 Strength athletes: for males 112-119 g/day, females 88-94 g/day
 Endurance athletes: for males 84-112 g/day, females 66-88 g/day
 U.S. average intake of protein: for males 95 g/day, females 65 g/day

ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Vitamins and Minerals to Support Activity
 Supplements
 Do
not enhance performance
 Deficiencies may impede performance
 Timing makes a difference; supplements take hours or
days to combine with cells.
 Nutrient-dense foods provide nutrients needed.
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Vitamins and Minerals to Support Activity
 Vitamin E
Protects against oxidative stress
 Does not improve performance
 More research needed
 Vegetables oils and antioxidant fruits and vegetables

 Iron
Iron losses in sweat
 Small blood losses in digestive tract
 Poor iron absorption

ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Vitamins and Minerals to Support Activity
 Iron
Deficiency
 Common
in physically active young women
 Consume good dietary sources of iron
 Iron-Deficiency
 Impairs
Anemia
physical performance
 Cannot perform aerobic activity and tire easily
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Vitamins and Minerals to Support Activity
 Sports
Anemia
 Low
blood hemoglobin for a short time
 Adaptive, temporary response to endurance activity
 Does not require supplementation
 Iron
Recommendations for Athletes
 Blood
tests should guide the decision
 Depends on the individual
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fluids and Electrolytes to Support Activity
 Fluid
Losses via Sweat
 Muscle
heat is 15-20 times greater when active than at
rest
 Cooling mechanism
 1 liter of sweat dissipates 600 kcalories of heat
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fluids and Electrolytes to Support Activity
 Hyperthermia
 Body
– an above-normal body temperature
heat builds up
 Triggers maximum sweating without sweat evaporation
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Symptoms of heat stroke – a dangerous
accumulation of body heat with accompanying
loss of body fluid
 Headache
 Nausea
 Dizziness
 Clumsiness
 Stumbling
 Hot, dry skin
 Confusion or other mental changes
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Prevention of heat stroke



Drink fluids
Rest in the shade when tired
Wear appropriate clothing
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fluids and Electrolytes to Support Activity

Hypothermia – a below-normal body temperature

Symptoms



Prevention



Shivering and euphoria
Weakness, disorientation, and apathy
Drink fluids
Wear appropriate clothing
Water Recommendations


1.0 to 1.5 mL/kcal expended
½ cup per 100 kcal expended
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fluids and Electrolytes to Support Activity

Fluid Replacement via Hydration
Full hydration is imperative for athletes.
 Those who are aware of their hourly sweat rate can replace lost
fluids.
 Plain, cool water is recommended.
 Endurance athletes may require carbohydrate-containing beverages.
 Hydration schedule

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

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Two hours before activity – 2-3 cups
15 minutes before activity – 1-2 cups
Every 15 minutes during activity – ½-2 cups
After activity – 2 cups for every pound of body weight lost
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fluids and Electrolytes to Support Activity
 Electrolyte
 Greater
Losses and Replacement
in the untrained
 Training improves electrolyte retention.
 Eat regular diet meeting energy and nutrient needs
 Endurance athletes may need sports drinks.
 Salt tablets worsen dehydration and impair performance.
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Fluids and Electrolytes to Support Activity
 Hyponatremia
 Decreased
concentration of sodium in the blood
 Causes
Excessive sweat
 Overhydration
 Drinking sports drinks during an activity; sports drinks offer
glucose polymers

ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Symptoms of hyponatremia

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



Severe headache
Vomiting
Bloating
Confusion
Seizure
Prevention of hyponatremia


Replace sodium during prolonged events.
Do not restrict salt in diets the days before
events.
ENERGY SYSTEMS, FUELS, AND NUTRIENTS
TO SUPPORT ACTIVITY

Poor Beverage Choices: Caffeine and Alcohol
 Caffeine
is a stimulant.
 Alcohol is not the beverage to replace fluids and
carbohydrate.
DIETS FOR PHYSICALLY ACTIVE PEOPLE
A diet that provides ample fluids and nutrientdense foods to meet energy needs will enhance
an athlete’s activity and overall health.
 Pregame and postgame meals should be light
and carbohydrate rich.

DIETS FOR PHYSICALLY ACTIVE PEOPLE

Choosing a Diet to Support Fitness
 Water
 Thirst
mechanisms are not as reliable
 Must be replenished
 Nutrient
Density – consume nutrient-dense foods
that are high in carbohydrate, moderate in fat, and
adequate in protein
DIETS FOR PHYSICALLY ACTIVE PEOPLE

Choosing a Diet to Support Fitness

Carbohydrate
60-70% total energy intake
 Avoid fiber-rich foods in the pregame meal.
 Added sugar and fat may be needed during intensive training.
 Liquid supplements should not replace foods.
 8-10 g carbohydrate/kg body weight during heavy training


Protein
Strength athletes: for males 112-119 g/day, females 88-94 g/day
 Endurance athletes: for males 84-112 g/day, females 66-88 g/day

DIETS FOR PHYSICALLY ACTIVE PEOPLE

Choosing a Diet to Support Fitness
A
Performance Diet Example
 Total
kcalories – 3000
 63% kcal from carbohydrate
 22% kcal from fat
 15% kcal from protein
 All vitamin and mineral RDAs are met
DIETS FOR PHYSICALLY ACTIVE PEOPLE

Meals Before and After Competition
 Pregame
Meals
 Fluids
 300-800
kcalories
 Carbohydrate-rich foods low in fat and fiber
 Light and easy to digest
 Postgame
Meals
 High-carbohydrate
meals
 Liquids often preferred
SUPPLEMENTS AS PERFORMANCEENHANCING AIDS
SUPPLEMENTS AS PERFORMANCEENHANCING AIDS




It is difficult to distinguish valid versus bogus claims
about ergogenic aids.
Many individuals believe these drugs, supplements, or
procedures will enhance physical performance in
activities.
Some are harmless, some have dangerous side
effects, and some are costly.
Most do not meet claims.
ERGOGENIC AIDS

Substances promoted as ergogenic aids
 Arginine – a nonessential amino acid
 Boron – a nonessential mineral
 Brewer’s yeast is falsely promoted as an energy
booster.
 Cell salts are sold as health promoting.
 Coenzyme Q10 is not effective in improving athlete
performance.
 DNA (deoxyribonucleic acid) is falsely promoted as an
energy booster.
 Epoetin is illegally used to increase oxygen capacity.
ERGOGENIC AIDS

Substances promoted as ergogenic aids








Gelatin is not a strength enhancer.
Ginseng has many side effects.
Glycine – a nonessential amino acid
Growth hormone releasers do not enhance performance.
High doses of guarana can stress the heart and cause
panic attacks.
Herbal steroids or plant sterols do not enhance hormone
activity.
HMB (beta-hydroxy-beta methylbutyrate) claims to
increase muscle mass and strength.
Inosine has been shown to reduce endurance of runners.
ERGOGENIC AIDS







Ma huang has many dangerous side effects.
Niacin does not enhance performance and has side
effects.
Octacosanol has false promotions.
Ornithine – a nonessential amino acid
Pangamic acid does not speed oxygen delivery.
Phosphate pills do not extend endurance or
increase efficiency of aerobic metabolism.
Pyruvate has common side effects of gas and
diarrhea.
ERGOGENIC AIDS








Ribose has some false claims.
RNA (ribonucleic acid) does not enhance performance.
Royal jelly is falsely promoted.
Sodium bicarbonate may cause intestinal bloating and
diarrhea.
Spirulina is potentially toxic.
Succinate is not a metabolic enhancer.
Superoxide dismutase (SOD) is useless; it is digested.
Wheat germ oil is not an energy aid.
DIETARY SUPPLEMENTS

Carnitine




Non-essential nutrient
Facilitates transfer of fatty acids across mitochondria
membranes
Supplementation does not increase muscle carnitine or
enhance exercise performance.
Chromium Picolinate


Essential mineral in carbohydrate and lipid metabolism
Supplementation has no effect on strength, lean body mass,
or body fat.
DIETARY SUPPLEMENTS

Complete Nutrition Supplements



Taste good and provide food energy, but do not provide
complete nutrition
Should not replace regular meals
Creatine


Some studies suggest improvement in muscle strength and
size, cell hydration and glycogen loading capacity
Safety issues and side effects
DIETARY SUPPLEMENTS

Conjugated Linoleic Acid (CLA)




Caffeine





Derived from linoleic acid, an essential fatty acid
Increases lean body mass in animals
Few human studies have been performed.
Caffeine can enhance performance by stimulating fatty acid release.
Adverse effects include stomach upset, nervousness, irritability,
headaches, and diarrhea.
Use in moderation.
Use as an addition to other fluids, not as replacement.
Oxygenated Water


Oxygen cannot enter the bloodstream by way of the GI tract.
The body gets oxygen from the lungs.
HORMONAL SUPPLEMENTS

Anabolic Steroids
 Illegal
 Authorities
ban use
 Plant sterols from herbs are poorly absorbed.
 Dangerous side effects on the body and the mind
HORMONAL SUPPLEMENTS

DHEA (dehydroepiandrosterone) and Androstenedione




Hormones that are precursors to testosterone
No evidence to support claims
Short-term effects are identified
Human Growth Hormone (hGH)



Used to build lean tissue and increase height if still growing
Extremely high cost
Many adverse side effects