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8/3/2019 CV Dynamic During Exercise
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Cardiovascular Effects to
CHRONIC Exercise
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CV Adaptations
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CV AdaptationsCentral heart
10-25% overall improvement
Moderate decline with inactivity
Peripheral muscle
50-300% overall improvement
Rapid decline with inactivity
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Effects of Aerobic Training on
Cardiovascular Function
Heart rate
Stroke volumea-v O2 difference
Cardiac output
VO2
Systolic bloodpressure
Diastolic blood
pressure
Coronary blood flow
Brain blood flowBlood volume
Plasma volume
Red blood cell mass
Heart volume
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VO2
Training has little effect on resting VO2
Training has little effect on submaximal VO2
Example, running at 8 mph at a 0% grade isalways at VO2 of ~24.9 ml/kg/min
Training increases maximal VO2 (VO2max)
15-20% (but as high as 50%) increase.
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VO2max
Frank Shorter, US Olympic Marathon winner, 71.3
Grete Waitz, Norwegian Marathon/10K runner, 73.5
Ingrid Kristiansen, ex-Marathon World Record Holder, 71.2
Derek Clayton, Australian ex-Marathon World Record holder, 69.7
Rosa Mota, Marathon runner, 67.2
Jeff Galloway, US Runner, 73.0
Paula Ivan, Russian Olympic 1500M Record Holder, 71.0
Jarmila Krotochvilova,Czech Olympian 400M/800M winner, 72.8
Lance Armstrong, 83
Steve Prefontaine,US runner, 84.4
Miguel Indurain, professional cyclist, 88
Bjrn Dhlie, cross-country skier - 96
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VO2max
Training to increase VO2max
Large muscle groups, dynamic activity
20-60 min, 3-5 times/week, 50-85% VO2max
Expected increases in VO2max
15% (average) - 40% (strenuous or prolonged training)
Greater increase in highly deconditioned or diseasedsubjects
Genetic predisposition
Accounts for 40%-66% VO2max
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VO2max
Higher Q at max
High a-v 02 difference
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CARDIAC OUTPUT
No change atrest
No change atsubmaxexercise
Increased atmaximalexercise
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HEART RATE
Lower resting HR
Parasympathetic
stimulation
Not always a true
indicator of fitness level
Lower submaximal heart
rate
Small effect on maximal
heart rate
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STROKE VOLUME
SV: 20% higher
all conditions
Larger heart size
Increase EDV
Increase blood volume
Increase contractility
Increase Ca release in myocardium
Similar ESV
Greater ejection fraction due to higher EDV
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STROKE VOLUME
Stroke volume may
continue to increase
up to maximal effort in
trained individuals
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Myocardial Hypertrophy
Aerobic training. Thicker walls and greatervolume
Strength training. Thicker walls only
Pathological. Thicker but weaker walls
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BLOOD VOLUME
Increased total blood
volume
Increased plasma volume
Increased red blood cells
Decrease in hematocrit (44to 41)
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Blood Volume
Total blood volume: 5.0 to 5.8 (14%)
Red blood cells: 2.2 to 2.4 (8%)
Plasma volume: 2.8 to 4.3 (35%)
Hematocrit: 44 to 41.
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A-V O2 DIFFERENCE
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A-V O2 DIFFERENCE
a-vO2 difference: slightly greater
Why?
Mitochondria
Increase in aerobic enzymes
Citrate synthase
3-hydrozyacylCoA dehydrogenase (3-HAD)
Myoglobin
Capillaries
Hemoglobin
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CV Function and Endurance
Training
Increase in parasympathetic inhibition of the SA
node (mostly at rest)
Decrease in sympathetic stimulation (mostly
during exercise)
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CV Function and Endurance
TrainingIncrease in EDV (increase chamber size)
Endurance training
Increase myocardial mass (increase force of contraction)
Strength training
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CV Function and
Endurance Training
At restSubmax.
Ex
Max. Ex
Heart Rate
Stroke Volume
Cardiac Output
Heart Size
Blood Volume
Hemoglobin
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LACATE LEVELS
Blood lactate levels
Increase removal. Why?
1. Increase capillaries
2. Decrease sympathetic stimulation causes an
increase blood flow to heart, liver, and type I
muscle fibers
Decrease production. Why?
1. ?
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Blood Lactate Levels
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BLOOD PRESSURE
Greatest effect on high blood pressure
Systolic: lower resting and submax
10 mm Hg decrease
Diastolic lower maximum
Why?
Weight loss
Reduce sympathetic stimulation
Other
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BLOOD FLOW
Blood flow
Coronary: higher at rest, submax, and max.
Greater SV and lower HR cause a reduction in
mVO2.
Greater vascularity only in diseased hearts
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BLOOD FLOW
Skeletal blood flow
Increase vasularity (capillaries)
Increased O2 and fuel delivery
Decrease resistance decrease afterload increase Q
Decrease flow at submax exercise
Compenstated by an increase O2 extraction
Greater blood flow to skin
Increase flow at maximal exercise (10%)
Due to greater Q and vasularity
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Questions?
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TRAINING THE
CARDIOVASCULAR
SYSTEM
CHAPTER 21
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Training the CV System
EXERCISING FOR HEATLH
Intensity:
65-90% of HR max or 50-85% of HR reserve
(HHR = HR max - HR rest)
RPE of 12-15
Duration: 20-60 minutes
Frequency: Most days of the week
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1. Over DistanceTraining
2. High-intensity,Continuous
Exercise3. Interval Training
TRAINING THE
CARDIOVASCULAR
SYSTEM
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Description: Long distances at less than
competitive pace (50-70%)
Results:Increase in mitochondriaIncrease in capillariesIncrease fat oxidation
Benefit: Increased endurance
OVER DISTANCE
TRAINING
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Description: Moderate distances at or nearcompetitive pace; 70-90%
Results:Strengthened heart (increase O2 supply tomuscles)Decrease in lactate production
Benefit: Increased lactate threshold
HIGH INTENSITY,
CONTINUOUS TRAINING
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Shorter distances above lactate threshold with periods of rest.
Able to perform large amount of high-intensity exercise
Results:Increase lactate removal
Increase neural stimulation
Increase anaerobic energy
Benefit: Improved in speed
INTERVAL TRAINING
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LACTATE REMOVAL
Lactate from FTmuscle fiber can becleared or removed
at:
1. Heart
2. Liver
3. ST musclefibers
34
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Oxygen Efficiency
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