Post on 24-May-2015
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)