Homework – due Thursday 12th Jan

Complete Progress Test 2. Use your notes and book to help you so that you score 35 out of 35 when I mark them.

Do not just copy sentences you must make sure you have a thorough understanding of each answer and come to ask me if you are unsure My free periods...

Tuesday 2 Wednesday 1&2 Friday 3 Monday or Friday period 4 (lower school lunch)

Slow Twitch (Type 1)

Fast Oxidative Glycolytic

(Type 2a/FOG)

Fast Glycolytic (Type 2b/FG)

Structural CharacteristicsColourSize Small Large LargeNo. of mitochondria

Large Moderate Small

No. of capillaries Large Moderate SmallMyoglobin concentration

High Moderate Low

Phosphocreatine (PC) stores

Low High High

Glycogen stores Low High HighTriglyceride (TG) stores

High Moderate Low

Functional CharacteristicsSpeed of contraction

Slow Fast Fastest

Force of contraction

Low High Highest

Fatigue resistance High Low LowestAerobic capacity High Low LowestAnaerobic capacity

Low High Highest

Best suited activity

100m, shot put, long jump

1500m Marathan, 10K

Effects on skeletal muscle Effects of warm up Effects of a cool down

• Increase in muscle/core body temperature

= reduction in muscle viscosity, leading to improvement in the efficiency of muscular contraction

= a greater speed and force of contraction due to a higher speed of nerve transmission

= an increased elasticity that reduces the risk of injury due to increased extensibility of tendons and ligaments

= improved co-ordination between antagonistic pairs

• Keeps the capillaries dilated, allowing oxygen rich blood to flush through the muscles

= an increase in the speed of lactic acid and carbon dioxide removal = reduce acidity level = reduced stimulation of pain receptors

Decreased risk of DOMS (delayed onset of muscle pain and soreness) experienced 24-48 hours after intense exercise due to microscopic tears in muscle fibres

Cardiovascular response to exercise

Heart rate, stroke volume and cardiac output

Learning objectives

Be able to: Provide definitions and resting values for SV,

HR and Q. Describe and explain changes in HR, SV and

Q during maximal and sub maximal activity.

Resting values:

Complete a table to show the average resting values of HR, SV and Q in both an untrained and trained person

Heart Rate (bpm)

Stroke Volume (mls/beat)

Cardiac Output

(L/min)

Average (Untrained)

Trained

Heart rate (HR) at rest

The number of ventricular contractions of the heart in one minute

Measuring heart rate (HR) Can measure carotid (neck) pulse or radial (wrist)

pulse

Measure and record your HR in beats per minute (bpm) in the following situations Standing Sitting Lying down (supine)

Describe the changes in HR due to changes in position. Suggest reasons why.

Compare HR values between members of the group. What could account for these differences?

Heart rate (HR) at rest

Average resting HR = 70-72 bpm

Low resting HR indicates high aerobic fitness

Resting heart rate below 60 is termed bradycardia

Bradycardia caused by ‘hypertrophy’ which is an increase in size and strength of cardiac (heart) muscle

wall

Maximal heart rate = 220 - Age

Stroke volume (SV) at rest

The volume of blood ejected from the heart ventricles each contraction

Stroke volume (SV) at rest

The volume of blood ejected from the heart ventricles each contraction

The difference in the volume of blood in the ventricle blood before and after ventricle contraction.

SV = EDV – ESV

SV = End Diastolic Volume – End Systolic Volume

Average volume at rest = 70mls per beat

What does the calculation below tell you?

Heart rate(beats per minute)

Stroke volume(ml per beat)

X

70 70X

? =

=

Cardiac output(mls/min)

=

4.9 L/min=

4900 mls/min

Cardiac Output (Q)

The volume of blood ejected by the heart ventricles in one minute

Q = SV X HR

Q = SV X HR

If an athlete has a resting Q of 5L/min, but a resting HR of 60, what is their resting SV?

Suggest reasons to explain why SV has increased.

SV = Q / HR

= 5 / 60

= 0.08333 L/beat

= 83.3 ml/beat

SV = Q / HR

= (5 x 1000) / 60

= 5000 / 60

= 83.3 ml/beat

Describe the relationship between stroke volume, heart rate and cardiac output and resting values for each

Cardiac Output = Stroke Volume x Heart Rate = 70ml x 70bpm

= 4900ml per minute

= 4.9 (5) Litres per minute

AT REST

MAX EXERCISE

Stroke Volume = 120 ml (untrained) 160ml (trained)

Cardiac Output = 20-40 L/min

Heart rate = 220 – Age

Resting values:Trained v Untrained

Complete a table to show the average resting values of HR, SV and Q in both an untrained and trained person

Suggest reasons for the changes seen in trained athletes

Heart Rate (bpm)

Stroke Volume (mls/beat)

Cardiac Output

(L/min)

Average (Untrained)

Trained

70bpm

50bpm

70-72 ml

100ml

5L (5000ml)

5L (5000ml)

Learning objectives

Be able to: Provide definitions and resting values for SV,

HR and Q. Describe and explain changes in HR, SV and

Q during maximal and sub maximal activity.

Cardiovascular response to exerciseDuring exercise.... Increased oxygen consumption as there is an increased

demand for oxygen for aerobic respiration to produce energy

In response... Heart rate increases Heart contracts more forcefully

causing stroke volume to increase

Q = SV X HR

Causes an overall increase in

cardiac output

CV response to exercise

The hearts response to exercise must be considered during both submaximal and maximal exercise

Sub maximal exercise Exercise performed at an intensity below an athlete’s maximal

aerobic capacity or maximum VO2 (oxygen capacity)

Maximal exercise Exercise performed at an athlete’s maximum aerobic capacity or

VO2 max

VO2 max is the measure of the peak volume of oxygen (VO2) you can consume and use in a minute.

HR response to exercise

Work RecoveryPrior

Hea

rt r

ate

(bpm

)

72

155

200 Maximal exercise

Sub maximal exercise

HR response to exercise Describe the sub maximal and maximal HR

response prior to, during and in the recovery from exercise.

Include:• Reasons for anticipatory rise in HR• Differences between the values reached in sub maximal and maximal exercise• Words such as rapidly, gradual, decrease, increase, plateau, exercise intensity, oxygen debt

SV response to exercise SV = EDV – ESV

Rest SV = 130ml – 60ml = 70ml

70ml pumped to body and 60ml left in ventricles in reserve

Exercise SV = 130ml – 10ml = 120ml

120ml pumped to the body and only 10ml in ventricles in reserve.

Stroke Volume Response to Exercise

Exercise Intensity

Str

oke

Vol

ume

(mls

/bea

t)

150

50

100 Stroke volume increases linearly as exercise intensity increases but only up to 40 – 60 % of maximal intensity.

After this point, SV values reaches a plateau

Maximal SV values are reached during sub-maximal exercise

Stroke Volume response to Exercise

Stroke Volume increases due to: 1. Increased capacity of the heart to fill

Increased Venous Return (blood returning to the heart) = Stretching of ventricular walls = Increases filling capacity = Increased End-Diastolic Volume (EDV) = Increased Stroke Volume

2. Increased capacity of the heart to empty Greater EDV = greater stretch of ventricular walls = Increased force of ventricular contraction (ventricular systole) = Increased contractility causes heart to almost completely

empty = increased Stroke Volume

SV response to exercise

SV reaches its maximal value at 40-60% of maximal exercise intensity (sub maximal intensity)

As exercise intensity increases towards maximal, cardiac output (Q) still needs to be increased to meet oxygen demand

What happens to allow Q to keep increasing so that an athlete can work maximally?

Cardiac Output Response to Exercise

Work RecoveryPrior

Maximal exercise

Sub maximal exercise

Car

diac

Out

put

(Litr

es/m

inut

e)

20

5

10

15-20

5

20-40

Q

L/min

KEY

SUB-MAXIMAL EXERCISE

MAXIMAL EXERCISE

REST EXERCISE RECOVERY

Q response to exercise Increase prior to exercise due to adrenaline acting upon the sino-

atrial node which increases HR (anticipatory response) Increases directly in line with exercise intensity in order to meet

the demand for oxygen from the working muscles Plateau’s when Q meets O2 demand in steady state exercise Sudden decrease when exercise stops Gradual decrease towards resting but still elevating above resting

as need to repay the oxygen debt

Resting, sub maximal and maximal values

Create a table to show the resting, sub maximal and maximal values of Heat rate (HR) Stroke volume (SV) Cardiac output (Q)

Example values

Exercise Intensity

Resting Sub-maximal (moderate intensity exercise)

Maximal (high intensity exercise)

SV 70ml

HR 70-72bpm

Q 5L/min

Example values

Exercise Intensity

Resting Sub-maximal (moderate intensity exercise)

Maximal (high intensity exercise)

SV 70ml 80-100ml untrained160-200ml trained

100-120ml untrained160-200ml trained

HR 70/72bpm 100-130bpm 220 - age

Q 5L/min Up to 10L/min 20-40L/min

Cardiovascular Drift

Cardiovascular drift (CVD, CVdrift) it is characterised by decrease in stroke volume and a parallel increase in heart rate

It is influenced by many factors, most notably the ambient temperature, hydration and the amount of muscle tissue activated during exercise.

To promote cooling, blood flow to the skin is increased. This results in a decrease in pulmonary arterial pressure and

reduced stroke volume in the heart. To maintain cardiac output at

reduced pressure, the heart rate must be increased.

Heart and a healthy lifestyle What is the heart’s main adaptation to sustained

involvement in physical activity?

Hypertrophy = increase SV = decreased resting HR

Increased potential to supply oxygen

Bradycardia = heart under less strain at rest = over life time could slow down deterioration of heart = improved quality of life

Learning objectives

Be able to: Provide definitions and resting values for SV,

HR and Q. Describe and explain changes in HR, SV and

Q during maximal and sub maximal activity.

Summary

At the onset of exercise cardiac output is increased by an increase in …………………………………………………..

When exercise intensity exceeds ……………………….. of an athlete’s maximal exercise intensity, stroke volume begins to ………………………..

Any further increase in cardiac output is a result of …………………………………………………………..

heart rate and stroke volume

40 – 60%

plateau

an increase in heart rate

Exam question

Draw a graph to show how the cyclist’s cardiac output changes in the following phases of the aerobic training session.• Prior to Exercise• Exercise Session• Recovery Period

Mark scheme1. Resting value

5L/min approx (4-6L/min)

2. Anticipatory rise before exercise due to adrenaline release stimulating the SA node

3. Sharp increase

4. Plateau between 10-20L/min

5. Initial sharp decline with slow decline towards resting level

May 2011

1. The volume of blood pumped around the body by the heart varies according to the intensity of exercise performed

a) Define stroke volume and give a resting value for the average adult

b) Describe the changes that take place to stroke volume from rest to maximal exercise levels

Homework – due Thursday 12th Jan

Complete Progress Test 2. Use your notes and book to help you so that you score 35 out of 35 when I mark them.

Do not just copy sentences you must make sure you have a thorough understanding of each answer and come to ask me if you are unsure My free periods...

Tuesday 2 Wednesday 1&2 Friday 3 Monday or Friday period 4 (lower school lunch)