Cardiorespiratory Fitness Stats

Mortality

# of deaths caused by disease

• Pulled from death certificates

Morbidity

Absense of health/presence of illness

Prevalence

# of people who have a disease

• Pulled from hospital admission records

Incidence

# of new cases of a disease

CVD

#1 killer in all population groups

Highest CVD death rates

Black + Latino/Hispanics

Right atrium

Receives blood with low oxygen content

Right ventricle

Low-oxygenated blood goes from here to lungs

Lungs

Add oxygen to blood

Left atrium

Oxygenated blood goes from lungs to here

Left ventricle

Oxygenated blood goes from here to tissue/muscles

Arteries

Carry oxygen-rich blood away from the heart

Veins

Carry oxygen-low blood back to the heart

Coronary arteries

Arteries that specifically supply the heart muscle itself with oxygen-rich blood

• The chambers of the heart don’t feed the heart muscle directly

Atherosclerosis

Narrow/blocked arteries

• Plaque build-up of fats, cholestrol, etc

• If blood cannot reach parts of the heart, that section is starved of oxygen → MI

CO/Q

Cardiac Output

• SV x HR

• Left ventricle

PVR: Peripheral Vascular Resistance

Prevention of blood flow

Cardiorespiratory system purpose

1. Deliver oxygen

2. Remove waste

3. Transport nutrients

4. Regulate temperature

Purposes of CR system dependent on CV

Waste removal, nutrient transportation, temperature regulation transportation

Central Oxygen Transport System

Heart: delivery and transportation of oxygen 

• CO = HR x SV

• Oxygen: lungs → blood → muscles

Peripheral

Muscles + tissue: utilization of oxygen

• Extract and use the oxygen from the blood

• a-vo2 difference

Arteries

Takes deoxygenated blood AWAY from the heart

a-VO2 difference

O2 in arteries - O2 in veins

High a-VO2 difference

A lot of oxygen used

Factors that influence response to acute changes

1. Fitness status

2. Temp/humidity, time of day, amt of sleep

3. Amt of food/caffeine

4. Alc/tobacco

5. Anxiety

Anticipatory phase

• Recognizing that it’s time to work out

• Parasympathetic withdrawal 

• Sympathetic drive

Parasympathetic system

Brings down heart rate

Sympathetic system

Brings up heart rate

• Norepinephrine, epinephrine

• Fight-or-flight

• Heightened senses

Steady state

The leveling-off of your heart rate at the max HR after about 1-3 mins 

Harder workload

Takes longer to reach steady state

More trained individuals

Reach steady state faster

Factors affecting stroke volume

1. Venous return to heart

2. LV capacity to enlarge

3. Contractility force of heart

4. Arterial pressure

5. Sympathetic stimulation 

Venous return to heart

Getting the blood to the heart → gets stronger/bigger

LV capacity to enlarge

Contain the blood and handle it

Contractility force of heart

Can the heart send out the blood?

• Will increase force once stronger/bigger

Arterial pressure

Blood leaving the heart (arteries → away)

• Higher pressure means lower SV

• Vasodilation 

Vasodialation

Increasing the diameter of the arteries to let more blood flow through

McArdle, Katch, and Katch

Compared CO during exercise upright vs. supine

• Cardiac output higher on SUPINE activity 

Supine CO higher because of …

SV

• Reduced gravity when lying down → easier venous return → more blood in heart → greater SV

• Blood doesn’t have to travel vertically up to the heart

Strictly increase with exercise intensity

1. Systolic BP

2. HR

Stay the same as exercise intensity increases

Mean arterial pressure

Increases until 40-60% VO2 max as exercise intensity increases

Stroke volume

Increases then slope decreases with exercise intensity

1. Cardiac output

2. a-VO2 difference

Both HR and SV influence CO

Before 40% VO2 max

Cardiovascular changes with acute exercises

1. Size

2. Age

3. Genetics

4. Sex

5. Level of fitness

Increases linearly with exercise intensity

VO2

Static exercise

Big ↑ in BP, smaller ↑ in HR

• Compression of blood vessels, ↑ TPR

Dynamic exercise

Moderate ↑ BP, ↑ HR

• Rhythmic contraction, good blood flow

Valsalva maneuver

 Breath-holding causes increased BP

• Compressed vessels 

O₂ deficit

When you start working out: the difference between the amount of oxygen you have readily available vs. the amount you need

O₂ debt

When you finish working out: the difference between the amount of oxygen your exercised-body is producing vs. how much oxygen you actually need

• Cool down stage → need less oxygen than when you were exercising