THE THE CARDIOVASCULAR CARDIOVASCULAR

SYSTEMSYSTEM

AnatomyAnatomyAcute ExerciseAcute Exercise

Chronic ExerciseChronic Exercise

Adaptations to Chronic Adaptations to Chronic ExerciseExercise

Increase VO2max.Increase VO2max. What does a higher VO2max What does a higher VO2max

indicate?indicate? What is responsible for an increase in What is responsible for an increase in

VO2max?VO2max? VO2max = Qmax x a-vO2 differenceVO2max = Qmax x a-vO2 difference

CARDIAC OUTPUT AND TRAINING

Cardiac OutputCardiac Output

What is responsible for a higher What is responsible for a higher maximal cardiac output?maximal cardiac output?

Q = HRmax x SVmaxQ = HRmax x SVmax Does HRmax increase with training?Does HRmax increase with training? Does SVmax increase with training?Does SVmax increase with training?

Stroke VolumeStroke Volume

What is responsible for a higher What is responsible for a higher SVmax?SVmax?

LEFT VENTRICULAR HYPERTROPHY

STROKE VOLUME AND TRAINING

DIFFERENCES IN EDV, ESV, AND EF

Filling Volume Residual VolumePercent of Total Volume Ejected

Stroke VolumeStroke Volume

A larger and stronger heart produces A larger and stronger heart produces an increase in stroke volume at rest, an increase in stroke volume at rest, submaximal exercise and maximal submaximal exercise and maximal exerciseexercise

A higher stroke volume at rest and A higher stroke volume at rest and submaximal exercise will allow for a submaximal exercise will allow for a lower heart rate without changing lower heart rate without changing cardiac outputcardiac output

Stroke VolumeStroke Volume

A higher maximal stroke volume will A higher maximal stroke volume will produce a higher cardiac outputproduce a higher cardiac output

A higher cardiac output will produce A higher cardiac output will produce a higher VO2maxa higher VO2max

A higher VO2max indicates a greater A higher VO2max indicates a greater ability for aerobic energy productionability for aerobic energy production

Stroke VolumeStroke Volume

What type of aerobic training is most What type of aerobic training is most effective in strengthening the heart effective in strengthening the heart and thus increasing stroke volume?and thus increasing stroke volume?

Heart RateHeart Rate

What affect will a larger SV have on What affect will a larger SV have on resting HR? resting HR?

What affect will a larger SV have on What affect will a larger SV have on submaximal exercise HR?submaximal exercise HR?

What affect will a larger SV have on What affect will a larger SV have on maximal exercise HR?maximal exercise HR?

HEART RATE AND TRAINING

Heart Rate Recovery Period

The time after exercise that it takes your heart to return to its resting rate

With training, heart rate returns to resting level more quickly after exercise

Has been used as an index of cardiorespiratory fitness

Should not be used to compare individuals to one another

Conditions such as altitude or heat can affect it

HEART RATE RECOVERY AND TRAINING

What other changes occur with What other changes occur with training that allow for an increase in training that allow for an increase in blood flow to the muscle?blood flow to the muscle?

Capillaries?Capillaries? Blood?Blood?

Blood FlowBlood Flow

CapillariesCapillaries

BLOOD AND PLASMA VOLUME AND TRAINING

Blood Volume?Blood Volume?

Viscosity?Viscosity?

Hematrocrit?Hematrocrit?

Red Blood Red Blood Cells?Cells?

Blood flow Blood flow distribution?distribution?

Endurance training, especially intense training, increases blood volume.

Blood volume increases due to an increase in plasma volume (increases in ADH, aldosterone, and plasma proteins cause more fluid to be retained in the blood).

Blood Volume and Training

Red blood cell volume increases, but increase in plasma volume is higher; thus, hematocrit decreases.

Blood viscosity decreases, thus improving circulation and enhancing oxygen delivery.

Changes in plasma volume are highly correlated with changes in SV and VO2max.

.

a-v O2 differencea-v O2 difference

What else needs to happen beside an What else needs to happen beside an increase in blood flow and blood increase in blood flow and blood volume in order for VO2max to volume in order for VO2max to increase?increase?

CapillariesCapillaries MyoglobinMyoglobin MitochondriaMitochondria

Cardiovascular Adaptations to Training

Left ventricle size and wall thickness increase

Stroke volume increases, as does Qmax and VO2max

Resting and submaximal heart rates decrease

Maximal heart rate stays the same or decreases

Blood volume increases

Increase in a-v O2 difference

More capillaries, myoglobin and mitochondria

Cardiac Output

a-v O2 difference

Cardiovascular Adaptations to Training

VO2VO2 QQ

HR SVHR SV

a-v O2 a-v O2 DifferenceDifference

RestRest SameSame DecDec IncInc SameSame

Submax Submax (same (same intensity)intensity)

SameSame DecDec IncInc SameSame

PerformancPerformancee

IncInc SameSame IncInc IncInc

MaxMax IncInc SameSame IncInc IncInc

Blood pressure changes little during submaximal or maximal exercise.

Resting blood pressure (both systolic and diastolic) is lowered with endurance training in individuals with borderline or moderate hypertension.

Blood Pressure and Training

Blood pressure during lifting heavy weights can cause increases in systolic and diastolic blood pressure, but resting blood pressure after weight lifting tends to not change or decrease.

Lactate ThresholdLactate Threshold

What affect would an increase What affect would an increase oxygen supply to the muscles during oxygen supply to the muscles during exercise have on the lactate exercise have on the lactate threshold?threshold?

What affect would this have on What affect would this have on aerobic performance?aerobic performance?

BLOOD LACTATE AND TRAINING

At RestAt Rest

At rest the heart can supply all the At rest the heart can supply all the needed oxygen with a cardiac output needed oxygen with a cardiac output of 5 liters per minute.of 5 liters per minute.

If the resting stroke volume is higher If the resting stroke volume is higher due to aerobic training, how will the due to aerobic training, how will the resting heart rate be different?resting heart rate be different?

What about parasympathetic What about parasympathetic stimulation?stimulation?

Submaximal ExerciseSubmaximal Exercise

Before training, running at 6 mph required a Before training, running at 6 mph required a cardiac output of 15 liters.cardiac output of 15 liters.

Also, before training this required a heart rate of Also, before training this required a heart rate of 140 bpm140 bpm

Since after weeks of training stroke volume Since after weeks of training stroke volume increases, what will happen to the heart rate while increases, what will happen to the heart rate while running at 6 mph? Why?running at 6 mph? Why?

What would happen to the running speed if the What would happen to the running speed if the trained person now ran at a heart rate of 140 trained person now ran at a heart rate of 140 bpm?bpm?

If the lactate threshold used to occur at 6 mph, at If the lactate threshold used to occur at 6 mph, at what speed will it occur now? Why?what speed will it occur now? Why?

Maximal ExerciseMaximal Exercise

Increase in VO2max Increase in VO2max Increase SV and blood volumeIncrease SV and blood volume Indicator of aerobic fitness levelIndicator of aerobic fitness level

CHANGE IN RACE PACE, NOT VO2MAX.

Aerobic Endurance and Performance

Major defense against fatigue which limits optimal performance.

Should be the primary emphasis of training for health and fitness.

All athletes can benefit from maximizing their endurance.

Static lung volumes remain unchanged; tidal volume, unchanged at rest and during submaximal exercise, increases with maximal exertion.

Respiratory rate stays steady at rest, decreases with submaximal exercise, and can increase dramatically with maximal exercise after training.

Respiratory Adaptations to Training

Pulmonary ventilation increases during maximal effort after training.

(continued)

Pulmonary diffusion increases at maximal work rates.

Respiratory Adaptations to Training

The respiratory system is seldom a limiter of endurance performance.

All the major adaptations of the respiratory system to training are most apparent during maximal exercise.

The a-vO2 diff increases with training due to more oxygen being extracted by tissues.

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