Transcript Chapter 16

Chapter 16
Exercise Prescriptions for Health
and Fitness
Physical Activity
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Any form of muscular movement
– Related to physical fitness
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Exercise
– A subset of physical activity for the purpose
of maintaining or improving physical fitness
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Can reduce the risk of death from all
causes
Physical inactivity is a primary risk factor
for coronary heart disease
The Dose-Response Relationship
of Drugs
Dose-Response Relationship of
Drugs (an example)
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The effect (response) of the amount of a
drug (dose)
– Potency – how much an amount can effect
– Slope – change in effect from change in dose
– Maximal effect – the most it can do
– Variability – different for different people
– Side effect – other unwanted action
The Dose-Response Relationship
for Exercise
@ 60-70% of max capacity
The Dose-Response Relationship
for Physical Activity
The Exercise Dose – F.I.T.
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Frequency
– Number of days per week
– Number of times per day
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Intensity
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Percent VO2max or VO2 reserve
Percent maximal HR or heart rate reserve
Rating of perceived exertion
Lactate threshold
Time (duration)
– Number of minutes of exercise
– Total kcals expended
– Total kcals per kg body mass
The Response to Exercise
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Improving fitness
– Thereby improving health
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Improving fitness and health
– Simultaneously or separately
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Improving fitness
– But not a specific health outcome
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Improving a specific health outcome
– But not improving fitness
Patterns in the Response to Exercise
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Acute responses
– Occur within one or several exercise bouts
but does not improve further
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Rapid responses
– Benefits occur early and plateau
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Linear
– Gains are made continuously over time
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Delayed
– Occurs only after weeks of training
Physical Activity and Health
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The benefits of physical activity may be
more related to total number of calories
expended than exercise intensity
The “Exercise Lite” recommendation
“Every U.S. adult should accumulate thirty
minutes or more of moderate-intensity
(3-6 METs) physical activity on most, preferably
all, days of the week.”
Benefits of Improving Fitness
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In previously sedentary subjects
– Small changes in physical activity result in
large health benefits with minimal risk
– Strenuous exercise
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Increases the risk of a heart attack during
activity
– Reduces overall risk (rest + exercise)
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Moderate to high levels of fitness
– Reduce the risk of death from all causes
General Guidelines for Improving
Fitness
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Screening
– Health status screening (PAR-Q)
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Progression
– Start with low-intensity exercise (walking)
– Then increase duration and/or intensity
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Warm-up, cool-down, and flexibility
– Light exercise and flexibility performed at
beginning and end of exercise session
Exercise Prescription for
Cardiorespiratory Fitness
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200-300 kcals per session
Considerations
– Weight loss
– Improved fitness
– Injury prevention
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Frequency
Intensity
Time (duration)
Optimal Training Intensity,
Duration, and Frequency
Exercise Intensity
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Corresponding to 60-80% VO2max
Target heart rate (THR) range
– Direct method
• HR at percentage of maximal work rate found
during GXT
– Indirect method
• 70-85% of maximal HR
• 60-80% of HR reserve (Karvonen) method
Target Heart Rate Range
Determined From GXT
Sequence of Physical Activity
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Walking
– Start at a comfortable speed for 15 minutes
– Gradually increase duration and speed
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Jogging
– Start by adding some running when walking
– Gradually increase speed/duration of running
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Games and sports
– Intermittent higher-intensity activities within
THR range
Strength Training
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Muscular strength is
an important
component of
physical fitness
– Strength to do
everyday tasks
– Strength for
“extraordinary” tasks
Strength Training
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Recommendations (health-related)
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Dynamic resistance exercises
Full range of motion
8-10 different exercises
8-12 repetitions per exercise
Weight that corresponds to 60 - 85% of 1RM
Large muscle groups first
Alternate muscle groups for rest
Progress with success
Flexibility
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Normal joint Range of Motion (ROM)
– Limited by bony structures
– Limited by connective tissue
– Limited by muscle tension
• “Re-set” tension / length
– Hyper mobility
Flexibility
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Training to improve
– Principles of exercise apply (O, S, R)
– Corollary applies too (consistency)
– Training variables apply (F, I, T)
– Best done when muscles are “warm”
– Best done - not to the point of pain
– Best done slowly – static not ballistic
Body Composition
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What makes up the body?
– Water
• 99 out of every 100 molecules
– Bone
• Skeletal, teeth
– Protein
• Membranes, organs, muscle
– Fat
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Membranes
Nervous tissue
Pericardial
Intramuscular
Intra-abdominal
Subcutaneous
Body Composition
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Body fat
– Stored carbons
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Adipose cells
– Increase volume to store carbons
– Multiply when they reach a particular size
• @ ~ 60 lb fat increase
• Do not “un-multiply”
Body Composition
Body Composition
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Estimation vs. Measurement
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Hydrostatic weighing
Skin fold calipers
Electrical impedance
Infrared absorbance
Dual X-ray Absorbtometry (DEXA)
Body Composition
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Energy Consumption vs. Energy Expenditure
– Handout
Body Composition
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144,000 bariatric surgeries expected in 2004—up from 16,200 in 1992
Severely obese are increasingly turning to this life-altering measure.
Most lose weight quickly and continue to lose for up to two years.
Also seeing improvements in almost all their obesity-related conditions.
1 in 100 who have gastric bypass dies
10 - 20 percent of all bariatric surgery patients require follow-up operations
to correct complications.
Almost 30 percent develop nutritional deficiencies, including osteoporosis,
anemia, and metabolic bone disease.
—Cate Lineberry - National Geographic
Remember……..
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Questions?
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