Transcript File - Miss Hanks` SPS1

Exercise Physiology
Circulatory System
What is the Human Circulatory System ?
• The main organ of the circulatory system is the
Human Heart.
• The Functions of the Circulatory System ?
• To transport blood around the body. The blood
itself also carries numerous other substances
which the body requires to function.
Circulatory System
• The main substance being Oxygen, carried by a
protein called haemoglobin, found inside red
blood cells.
• Blood also carries waste products, such as
Carbon Dioxide away from muscles and organs
in order to be dispelled by the lungs.
Circulatory System
Circulatory System
DID YOU KNOW!!??
1. It takes 20 seconds for blood to circulate the entire
body. Oxygenated blood leaves the aorta about1 mile
an hour.
2. The power output of the heart ranges from 1-5
watts per minute. Which is the equivalent to the usage
of a 60 watt bulb. It has been said that enough energy
is produced a day to drive a truck 20 miles.
Circulatory System
3. Human blood is colourless, it is the hemoglobin that
makes it red.
4. Due to the heart having its own electrical impulse, it
will continue to beat even when removed from the body
as long as it has an adequate supply of oxygen.
5. On average, the human body has about 5 liters
(almost 9 pints) of blood continually traveling through it
by way of the circulatory system. A kitchen tap would
need to be turned on all the way for at least 45 years to
equal the amount of blood pumped by the heart in an
average lifetime.
Circulatory System
Terminology
• Heart rate is simply the number of heart beats per
minute.
• Stroke volume is the volume of blood, in millilitres
(mL), pumped out of the heart with each beat.
• Cardiac output: is the volume of blood pumped by the
heart per minute (mL blood/min). Cardiac output is a
function of heart rate and stroke volume. Cardiac Output
in mL/min = heart rate (beats/min) X stroke volume
(mL/beat)
Circulatory System
• An average person has a resting heart rate of 70
beats/minute and a resting stroke volume of 70
mL/beat. The cardiac output for this person at rest is:
• Cardiac Output = 70 (beats/min) X 70 (mL/beat) = 4900
mL/minute.
• The total volume of blood in the circulatory system of an
average person is about 5 litres (5000 mL). During
vigorous exercise, the cardiac output can increase up to
35 litres/minute
Respiratory System
Function of the Respiratory System
• The function of the human respiratory system is
to transport air into the lungs and to facilitate
the diffusion of Oxygen into the blood stream.
Its also receives waste Carbon Dioxide from the
blood and exhales it.
Respiratory System
Terminology
• Respiratory Volumes: is the amount of air
inhaled, exhaled and stored within the lungs at any
given time
• Tidal Volume: the amount of air which enters the
lungs during normal inhalation at rest. The average
tidal volume is 500ml. The same amount leaves the
lungs during exhalation.
• Total Lung Capacity: This is the total amount of
air the lungs can hold. The average total lung
capacity is 6000ml, although this varies with age,
height, sex and health.
Respiratory System
DID YOU KNOW!!??
1. Due to the heart being located on the left- hand side of
most humans – the right lung is slightly larger than the
left.
2. The highest speed at which expelled particles from
a sneeze have been measured to travel is 103.6 mph (167
km/h). Guiness book of records 2004
3. We lose half a litre of water a day through breathing.
ENERGY SYSTEMS
Muscle Contraction causes Movement, but requires
ENERGY to do so!!!
The ATP Molecule
a. Adenosine Tri-phosphate (ATP)
Adenosine
P
P
P
ATP Molecule
•
ATP replenishes with the use of Oxygen (Aerobic)
•
Wastes products are expired and breathed out
• Unfortunately there is only enough ATP in the muscles to
last for 2 seconds.
• The body has 3 other systems to replenish ATP to ensure
we can keep exercising.
ATP Production during Exercise
3 Systems used to replenish ATP
•ATP-CP System
•Anaerobic (Lactic Acid) Glycolysis
•Aerobic Glycolysis
The ATP-CP System
• Duration: 1-15 seconds
• When: Sudden increase in intensity (whilst oxygen supply catches
up), or short intense movements
• This system breaks down stored Creatine Phosphate (CP) in the
muscle; it requires no oxygen (anaerobic)
• Limitations: by amount of CP the body can store.
• What sports predominantly use this energy system?
ATP-CP Energy System
• Replenishes ATP rapidly by breaking down Creatine
Phosphate releasing energy to reform ATP
• Active at the beginning of all forms of activities
• Especially important in high intensity exercises like weight
lifting that require short bursts of energy.
• Only a small quantity of PC can be stored. Athletes do try
to load up with supplements
The Anaerobic Lactic System
• Duration: Up to 3 minutes
• When: Sudden increase in intensity (whilst oxygen supply catches
up)
• Provides energy for moderate to high intensity exercise. The system
uses energy from the breakdown of carbohydrates (glucose) and
requires no oxygen.
• Limitations: Production of lactic acid.
• What Sports?
Anaerobic (Lactic Acid) Glycolysis
• Breakdown of carbohydrates (glycolysis) for fuel when
without oxygen eg beginning of exercise or high intensity
workout >85% of HRmax
• Results in formation of lactic acid, which causes muscle
fatigue
Aerobic System
• Duration: Unlimited
• Predominant energy supplier for low to moderate
intensity exercise <85% HR MAX
• The system breaks down both carbohydrates and fats
for energy and requires oxygen (aerobic).
• What Sports?
Aerobic Glycolysis
• Replenishes ATP with the use of oxygen
• System works at rest and during very low intensity
exercise
Energy System Interplay
• The interplay of energy systems refers to the dominant energy
system at any given time during an event.
• All energy systems make ATP from the start of physical activity.
However, one is more dominant than the others at particular times,
depending on the intensity & duration of the activity.
Short Term Effects of Exercise
• When we begin to exercise the body has to respond
to the change in activity level
Short Term Effects of Exercise
Circulatory System
• The release of adrenaline (often before exercise even
begins) causes the heart rate to rise
• Increase in Cardiac Output
• Increases in Lactic Acid (produced during the early
anaerobic phase of exercise), Carbon Dioxide (due to
increased rates of energy production) and temperature
all act as stimuli to the cardiac control centre which
responds by further increasing the heart rate
• Blood pressure increases, thus increasing flow rate and
the speed of delivery of O2 and nutrients to the working
muscles
Short Term Effects of Exercise
Respiratory System
• Changes in the concentration of CO2 and O2 in
the blood are detected by the respiratory centre
which increases the rate of breathing
• The diaphragm and surrounding muscles work
harder to further increase the expansion during
inhalation, to draw in more air.
Short Term Effects of Exercise
Muscles
• The higher rate of muscle contraction depletes
energy stores
• Myoglobin (protein that carries and stores
oxygen in muscle cells) releases its stored
Oxygen to use in aerobic respiration. O2 can
now be diffused into the muscle from the
capillaries more quickly due to the decreased O2
concentration in the muscle
Short Term Effects of Exercise
When you begin to exercise your body must
immediately adjust to the change in activity level.
Energy production must increase to meet demand
with changes to the predominant energy system
and fuel source occuring throughout the exercise in
order to maintain the required level of
performance.
Short Term Effects of Exercise
Responses to Anaerobic Exercise
• In order to immediately meet the sudden higher energy
demand, stored ATP is the first energy source. This lasts
for approximately 2 seconds.
• When stored ATP is used up the ATP-PC system kicks in
but it can only last 8-10 seconds before PC stores are
depleted.
• The lactic acid system (Anaerobic glycolysis) must then
take over as the predominant source of energy
production. High intensity (but sub-maximal) exercise
can last for between 3 and 5 minutes using this system
• If the exercise continues at a high intensity, and Oxygen
is not available at a fast enough it interferes with
muscular function. This is called the Lactate threshold.
Short Term Effects of Exercise
Responses to Aerobic Exercise
• Due to the necessity of Oxygen being present for
aerobic metabolism, the first few minutes of low
to moderate intensity exercise are powered by
anaerobic metabolism.
• Continued low to moderate intensity exercise is
then fuelled by carbohydrate and fat stores using
aerobic metabolism.
Long Term Effects of Exercise
• Regular exercise results in adaptations to the
circulatory, respiratory and muscular systems in
order to help them perform better under
additional stress.
Long Term Effects of Exercise
• Circulatory System
• The cardiac muscle surrounding the heart gets bigger,
resulting in thicker, stronger walls and therefore increases
in heart volumes. The more blood pumped around the
body per minute, the faster Oxygen is delivered to the
working muscles.
• The number of red blood cells increases, improving the
bodies ability to transport Oxygen to the muscles for
aerobic energy production.
• The resting heart rate decreases in trained individuals due
to the more efficient circulatory system.
• The accumulation of lactic acid is much lower during highlevels activity, due to the circulatory system providing
more Oxygen and removing waste products faster.
Long Term Effects of Exercise
• Respiratory System and Exercise
• The respiratory muscles (Diaphragm/intercostals)
increase in strength.
• This results in larger respiratory volumes, which
allows more Oxygen to be diffused into the blood
flow
Long Term Effects of Exercise
Muscles
• The muscles, bones and ligaments become
stronger to cope with the additional stresses and
impact put through them.
• The amount of myoglobin within skeletal muscle
increases, which allows more Oxygen to be
stored within the muscles and a larger amount of
glycogen can be stored for energy.
Training for Volleyball
• If you were to start a 6 month training
programme for Volleyball what methods of
training might you use?
• What effect would these have?
Methods of Training
You may use the following if training for Volleyball:
•
•
•
•
Weight Training (focused on power)
Plyometrics (focused on power)
Interval Training (ATP-CP)
Circuit (Power and Agility based)