Exercise Physiology Final: Cardiovascular and Pulmonary Responses and Adaptations to Exercise

Systolic (Blood Pressure)

High pressure (top number); Occurs during ventricular contraction - pumping of heart

Diastolic (Blood Pressure)

Low pressure (bottom number); Occurs ventricular relaxation - filling of heart

Cardiac Chambers & Heart Chambers: Atria contracts during…

Ventricular relaxation

Cardiac Chambers & Heart Chambers: Ventricles contract during…

Atrial relaxation

Cardiac Chambers & Heart Chambers: Synchronized action allows for…

Higher stroke volume

P-Wave

Atrial Depolarization - Causes contraction

QRS Complex

Ventricular Depolarization - Contraction

Atrial Repolarization - Relaxation that’s hidden in ventricular depolarization

T-Wave

Ventricular Repolarization - Relaxation

What are some physiologically variable changes with incremental exercise?

Cardiac output, heart rate, stroke volume, systolic blood pressure, and diastolic blood pressure

Physiological Variable Changes with Incremental exercise: Cardiac Output

The quantity of blood pumped by the heart each minute which is the product of heart rate and stroke volume and expressed as Liters per minute

🫀Increases but later can create moderate rise due to stroke volume limit

Cardiac Output Equation

Q=HR\cdot SV

Stroke Volume definition

The amount of blood ejected in each heart beat from LV

Physiological Variable Changes with Incremental exercise: Heart Rate (Regulating Factors)

Direct relationship to the Autonomic Nervous System in which:

• Increased parasympathetic (vagal) activity - SA node inhibition - dec HR

• Increased sympathetic activity - SA node node stimulation - inc HR

🫀Increases until max

Physiological Variable Changes with Incremental exercise: Body Temp

Low temp - Dec HR

High temp - Inc HR

🫀Minor contributor

Physiological Variable Changes with Incremental exercise: Stroke Volume

Amount of blood ejected from Left Ventricle per beat

🫀 Increases to 40-60% of max

Physiological Variable Changes with Incremental exercise: Systolic Blood Pressure

High pressure/top number that occurs during ventricular contraction

🫀Increases

Physiological Variable Changes with Incremental exercise: Diastolic Blood Pressure

Low Pressure/ Bottom number that occurs during ventricular relaxation

🫀General Unchanged

What effects does Vessel length have on blood flow?

Increase in length ~ increase in resistance ~ decreases in blood

• No possible adaptations

What effects does Blood Viscosity have on blood flow?

Increase in viscosity ~ increase in resistance ~ decreases in blood flow
• Some possible adaptations

What effects does Vessel Radius have on blood flow?

Increase in vessel radius ~ decrease in resistance ~ increase in blood flow

• exponentially affects flow to the fourth power

If you were to reduce vessel radius by ½ what would happen?

Blood flow would be diminished to 1/16 it’s normal amount

What effect does body temp have on Heart Rate?

A low body temperature equates to a decrease in heart rate. A high body temp equated to a higher heart rate.

What effects does the Parasympathetic (vagal) activity of the Autonomic Nervous system have on heart rate?

Increased activity - SA node inhibition - decreased heart rate

What effects does the Sympathetic activity of the Autonomic Nervous system have on heart rate?

Increased sympathetic activity - SA node stimulation – increased heart rate

Auscultation

When the 1st Atrioventricular valves and 2nd Semilunar valves close together creating the lubdub sound heard in the stethoscope.

What valves (left and right) are used when then 1st Atrioventricular Valves close together?

Bicuspid/mitral valve (left) and Tricuspid valve (right)

What valves (left and right) are used when then 2nd Semilunar Valves close together?

Aortic valve (left) and Pulmonic valve (right)

Cardiac output is maintained by…

prolonged exercise

Equation for stroke volume

SV=EDV-ES

End Systolic Volume (ESV)

Amount of blood left behind after pumping phase

Preload

Reflects End-Diastolic Volume (EDV) and is determined by venous return to the heart. It influences stroke volume by dictating the amount of blood the ventricles can pump with each contraction.

More blood filling the left ventricles…

More stroke volume

High Preload

High stroke volume

Low Preload

Low stroke volume

Afterload

Reflects Mean Arterial Pressure (MAP) of the Aorta in which high pressure in the vessels acts as a “wall” blocking stroke volume.

High afterload

Low stroke volume

Low afterload

High stroke volume

Gas flows from areas of high pressure to…

areas of low pressure

General pressure differences among blood vessels (Highest pressure to lowest pressure)

Arteries ~ Arterioles ~ Capillaries ~ Venules ~ Veins

What are the four chambers of the heart?

left atrium, left ventricle, right atrium, and right ventricle

Right Atrium (RA)

The thin-walled and smallest chamber of the heart that receives deoxygenated blood from the body through the superior and inferior vena cavae. It contains the sinoatrial (SA) node which is the hearts natural pacemaker and has a partly smooth and partly pectinate muscle.

Right Ventricle (RV)

The chamber of the heart that pumps deoxygenated blood to the lungs via the pulmonary artery. It has a thicker muscular wall compared to the right atrium but thinner than the left ventricle, and contains the right atrioventricular valve. It also contains a crescent/pocket shaped cavity cross section.

Left Atrium (LA)

The chamber of the heart that receives oxygenated blood from the lungs via the pulmonary veins. It has a smooth wall structure and contains the left atrioventricular (mitral) valve, playing a crucial role in the flow of blood into the left ventricle.

Left Ventricle (LV)

The chamber of the heart that pumps oxygenated blood to the body through the aorta (to the entire body). It has the thickest and largest muscular wall of all the heart chambers, ensuring powerful, efficient contractions, and contains the left atrioventricular (mitral) valve.

Sinoatrial (SA) Node ➡

depolarizes and sends positive energy to the atriums, then causing the atriums to depolarize and contract sending blood through the bicuspid and tricuspid into the ventricles

Atrioventricular Node ➡

depolarizes and sends positive energy along the Bundle of His

Bundle of His ➡

receives depolarization signals and sends positive energy to the right and left bundle branches

The Branches ➡

depolarize and send the positive energy to the Purkinje Fibers within the ventricles

Purkinje Fibers ➡

depolarize and cause ventricles to also depolarize and contract sending blood out of the heart via the aorta (to the body) and the pulmonary arteries (to the lungs)

Formula for flow of liquid through a vessel

Flow = Pressure/Resistance

What factors affect resistance of flow?

vessel radius, length, and blood viscosity.

What factor that affect resistance of flow is most IMPORTANT? Why?

Vessel radius because it exponentially affect the flow to the fourth power as reducing the radius by ½ diminishes flow to the 1/16 normal amount

What are the general mechanisms for redistribution of blood flow?

Vasoconstriction and vasodilatation

Vasodilation

widening blood vessels, which decreases vascular resistance and increases blood flow to specific areas. Redistribution of blood flow is increased to working skeletal muscle

Vasoconstriction

the process of narrowing blood vessels, which increases vascular resistance and reduces blood flow to specific areas. Redistribution of blood flow is reduced to non-working organs.

Autoregulation

when vasodilation and vasoconstriction self regulate blood flow based on demand

What is a healthy heart rate?

180/20

Sources of improvement for VO2max: Heart Rate Max (HRmax)

0% improvement due to it being solely genetic

Sources of improvement for VO2max: Stroke Volume Max (SVmax)

50% improvement due to increased preload, decreased afterload, and increased ventricular contractility

Sources of improvement for VO2max: Arteriovenous Blood Oxygen Max (a-VO2 max)

50% improvement due to increased muscle blood flow, increased capillary density, and increased number of mitochondria

What we can expect for people to get increased maximum oxygen consumption?

Deconditioned athletes will have a significant increase, but elite athletes probably will not as training at low levels of intensity will not see much change, but prolonged or intensive work will.

Early Losses

Occurs within days to weeks and is due to decrease in Stroke Volume

Later Losses

Occurs within weeks to months and is due to decreases in the Maximum Aerobic Capacity (a-VO₂) difference

Anaerobic Threshold (AT)

Intensity at which lactate and/or ventilation rise exponentially rather than predictably

• The combined lactate and ventilatory threshold phenomena

At the Alveolus, gas is exchnaged…

at the cellular level

High to Low PO₂

Alveolus ~ lung capillary blood ~ muscle cell (ABC)

High to Low PCO₂

Muscle cell ~ lung capillary blood ~ alveolus

How exercise prescriptions might differ with respect to Anaerobic Threshold and the General Population.

Neither are better, this is an irrelevant issue to most individuals who are exercising for overall health improvements; any intensity is fine, the goal is to influence lifestyle factors

How exercise prescriptions might differ with respect to Anaerobic Threshold and the Fitness Enthusiasts Population.

Anaerobic Threshold is most relevant because the goal for fitness/competition is to exercise at the highest intensity possible without causing rapid lactic acid accumulation

What percent of CO₂ is converted to bicarbonate in blood?

70% due to pressure but, conversion is temporary and facilitates enhanced transport

What percent of CO₂ is converted to hemoglobin in blood?

20%

What percent of CO₂ is dissolved in the blood?

10%

Body Fat recommendations for males

mean 15%

Body Fat recommendations for females

mean 20%

Obesity in males

>28%

Obesity in females

>32%

What are the causes of obesity?

Hypertrophy and Hyperplasia

Hypertrophy

increased cell size

Hyperplasia

Increase cell number which cannot be reversed and occurs when adipose cells are unable to store triglyceride so the body makes more adipose cells to meet the demand

Approximately ______ of the U.S. is obese and another ____ is overweight.

1/3

What are some Anthropometric measures?

BMI (based on height and weight comparisons), Waist to Hip Ratio, Skinfold, Densitometry (hydrostatic/underwater weighing)

BMI: Low-Risk

18.5-24.9

BMI: Overweight

25.0-29.9

BMI: Obese

30+

Waist-to-Hip Ratio: Males

Greater than 0.95 (apple shape); high risk

Waist-to-Hip Ratio: Females

Greater than 0.8 (pear shape); moderate risk

Waist-to-Hip Ratio

Based on body shape and location of excess fat with a focus on waist circumference/hip circumference

What is the relationship between density and body fat?

Adipose tissue is less dense than lean tissue causing muscle to weigh more than fat.

Underwater Weighing

Involves weighing submerged body; lower density of fat causes buoyancy compared to lean tissue

Skin fold

Involves measuring thickness of subcutaneous fat with a caliper device; collecting data allows us to calculate body densities and later on body fat percentage which is used to assess individuals

Skin Fold: High Density

low fat and high lean

Skin Fold: Low Density

high fat and low lean

Rest to Work Transition effect on Prolonged exercise

Rapid rise early and slow rise later on towards stead state

Rest to Work Transition effect on Incremental exercise

Linear rise up to moderate intensity and a sharp rise beyond moderate intensity in which the infliction point occurs reflecting the Ventilatory Threshold

Ventilatory Threshold

due to the body’s need for more O2 to keep up with intensity demand that is placed upon it

Training Status effect on Prolonged Exercise

Ventilation for trained individuals is lower when at the same work rate as untrained individuals

Training Status effect on Incremental Exercise

VT occurs at a higher work rate for trained individuals compared to untrained individuals

Classical Method of Glycogen Loading

▪ 1 day of prolonged intense exercise to empty glycogen stores

▪ 3 days of normal training with consumption of 50% arb

▪ 3 days if no training with consumption of 90% carbs

Modified Methods of Glycogen Loading

▪ 3 days of tapering long workouts to medium workouts with consumption of 50% carbs

▪ 2 days of short workouts with consumption of 70% carbs

▪ 1 day of rest with consumption of 70% carbs

T/F: Pulmonary system is not a limiting factor during submaximal exercise

True