1. PHED 1 Applied Physiology Responses to Exercise
AS PE
PHED 1
Applied Physiology
Responses to Exercise

2. HEART DYNAMICS AVERAGE RESTING HEART RATE VALUES MALES - 70 bpm
The Resting Heart
HEART DYNAMICS
AVERAGE RESTING HEART RATE VALUES
MALES - 70 bpm
FEMALES - 72 bpm
CARDIAC OUTPUT
= SV x HR (this is the formula used for each calculation)
SV = stroke volume - measured in ml (cm3)
AT REST
untrained person endurance athlete
= 75 (ml) x 70 (bpm) = 109 (ml) x 48 (bpm)
= 5.25 l min-1 = 5.23 l min-1
DURING MAXIMAL EXERCISE
untrained person endurance athlete
= 120 (ml) x 200 (bpm) = 190 (ml) x 200 (bpm)
= 24 l min-1 = 38 l min-1

3. TRAINING AND PERFORMANCE
ADAPTATIONS PRODUCED BY AEROBIC TRAINING
CARDIAC RESPONSE
blood plasma volume increases with training
therefore increased blood plasma volume enters left ventricle
increasing the stretch of the ventricular walls by the Frank-Starling mechanism (starlings law )
cardiac hypertrophy – heart becomes bigger and stronger (mainly left ventricle)
increased ventricular muscle mass and stronger elastic recoil of the myocardium
causes a more forceful contraction during ventricular systole
therefore stroke volume increases and HR decreases (bradycardia)
and hence providing more oxygen per pulse
Ejection Fraction is greater
the net effect is up to 20% bigger stroke volume and greater oxygen delivery to muscles

4. TRAINING AND PERFORMANCE
ADAPTATIONS PRODUCED BY AEROBIC TRAINING
cardiovascular system becomes more efficient
VASCULAR RESPONSE
more haemoglobin is created and is available in blood for oxygen transport
there is increased capillarisation of trained muscle
hence increase in a-vO2 diff
increased elasticity and thickness of smooth muscle of arterial walls makes walls tougher and therefore less likely to stretch under pressure
this maintains blood pressure forcing blood through capillary network
BLOOD VESSELS IN THE HEART
blood flow to heart decreases because heart muscle is more efficient
hence decrease in resting HR

5. Cardiovascular Drift Page 57 of text book
As exercise continues stroke volume drops
? We sweat, blood loses plasma, venous return drops – starlings law
HR increases to compensate
Cardiac output starts to increase – we need more O2 to cool down the body

7. TRAINING AND PERFORMANCE
ADAPTATIONS PRODUCED BY AEROBIC TRAINING
RESPIRATORY RESPONSE
decrease in breathing rate (f) at submaximal workloads
and increase in breathing rate (f) at maximal workloads
hence large increase in volume of air breathed per minute
increase in pulmonary blood flow and plasma volume
efficiency of alveoli improves, and more alveoli are utilised
hence increased gaseous exchange
RECOVERY
improved oxygen recovery
with better muscle capillarisation and efficient cool-down, lactic acid removal is improved

8. ARTERIOVENOUS OXYGEN DIFFERENCE
Respiratory Response to Exercise
ARTERIOVENOUS OXYGEN DIFFERENCE
a-vO2 diff
this expresses the difference between the oxygen carried by blood in arteries and veins
and represents the amount of oxygen delivered to working tissue in the capillary system
a-vO2 diff - AT REST
venule capillary arteriole
blood flow
15ml O2
per 100ml blood
20ml O2
per 100ml blood
a-vO2 diff = 5ml
per 100ml blood
a-vO2 diff - DURING INTENSE EXERCISE
venule capillary arteriole
blood flow
5ml O2
per 100ml blood
20ml O2
per 100ml blood
a-vO2 diff = 15ml
per 100ml blood

9. TRAINING AND PERFORMANCE
ADAPTATIONS PRODUCED BY AEROBIC TRAINING
pulmonary systems become more efficient
RESPIRATORY RESPONSE
musculature of torso becomes stronger and more efficient
lung volumes increase slightly, greater volumes of air can be breathed per breath
increase in VC at the expense of RV

10. Big words you must know Starlings Law Cardiovascular Drift
Stroke Volume
Bradycardia
Cardiac Output
Capillarisation
Ejection Fraction
Ventricular Systole
Venous Return
Anticipatory Rise
A – Vo2 Diff
Cardiac Hypertrophy

11. Practice Questions
Jan 2011 Paper
June 2011 Paper