Transcript Exercise Physiology

Exercise
Physiology
Circulatory System
What is the Human Circulatory System ?
• The main organ of the circulatory
system is the Human Heart. The other
main parts of the circulatory system
include the Arteries, Arterioles,
Capillaries, Venules, Veins and Blood.
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.
The Blood Contains…..
• The main substance being Oxygen, carried by a
protein called haemoglobin, found inside red
blood cells.
• White blood cells for fighting disease and
infection.
• Blood contains platelets essential for clotting the
blood, which occurs following an injury to stop
blood loss.
• Blood also carries waste products, such as Carbon
Dioxide away from muscles and organs in order
to be dispelled by the lungs.
Circulatory System
How the Circulatory System Works
There are three circulatory processes
occurring simultaneously within the body.
• 1. Systemic Circulation carries blood
around the body
• 2. Pulmonary Circulation carries blood to
the lungs
• 3. Coronary Circulation provides the heart
with its own supply of blood.
Systemic Circulation
The blood continues back
towards the heart,
through the veins, into
the right atrium.
The heart pumps
oxygenated blood out of
the left ventricle, through
the Aorta (the largest
artery in the body).
This Carbon dioxide
passes back across the
walls of the capillaries,
into the blood stream.
Once the nutrients are
used during energy
production (metabolism)
a waste product called
Carbon Dioxide is formed.
The blood is then
transported around the
body to the muscles and
organs.
Here the Oxygen (and
other nutrients) passes
through the capillaries,
into the tissues where it
can be used to produce
the energy muscles
require to contract.
Circulatory System
Pulmonary Circulation
• Once blood returns to the heart it is then
pumped from the right ventricle through the
Pulmonary arteries to the lungs, where the
waste carbon dioxide can be expelled and more
Oxygen collected. The Pulmonary vein carries
oxygenated blood back to the left atrium of the
heart, where the cycle starts again.
Circulatory System
Circulatory System
• 3. Human blood is colourless, it
is the hemoglobin that makes it red.
• 4. Red blood cells live for upto 4 months
and make approximately 250,000 round
trips around the body before returning to
the bone marrow, where they were born,
to die. Between 2.5 and 3 million red blood
cells (erythrocytes) are lost and replaced
every second.
Circulatory System
Did you know!!??
1. It takes 20 seconds for blood to circulate the entire
body. Oxygenated blood leaves the aorta about about 1
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
5. 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.
6. 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
milliliters (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 liters (5000 mL). According to our
calculations, the entire volume of blood within the circulatory
sytem is pumped by the heart each minute (at rest). During
vigorous exercise, the cardiac output can increase up to 7 fold
(35 liters/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
What is the Respiratory System?
• The respiratory system consists of the following parts,
divided into the upper and lower respiratory tracts:
Respiratory System
Parts of the Upper Respiratory Tract
Mouth, nose & nasal cavity: The function of this
part of the system is to warm, filter and moisten
the incoming air
Pharynx: Here the throat divides into the trachea
(wind pipe) and oesophagus (food pipe). There is
also a small flap of cartilage called the epiglottis
which prevents food from entering the trachea
Larynx: This is also known as the voice box as it
is where sound is generated. It also helps protect
the trachea by producing a strong cough reflex if
any solid objects pass the epiglottis.
Respiratory System
Parts of the Lower Respiratory Tract
• Trachea: Also known as the
windpipe this is the tube which
carries air from the throat into the
lungs. It ranges from 20-25mm in
diameter and 10-16cm in length.
• Bronchi: The trachea divides into
two tubes called bronchi, one
entering the left and one entering
the right lung. The left bronchi is
narrower, longer and more
horizontal than the right.
Respiratory System
Bronchioles: Tertiary bronchi continue to
divide and become bronchioles, very narrow
tubes, less than 1 millimeter in diameter.
Alveoli: Individual hollow cavities contained
within alveolar sacs (or ducts). Alveoli have
very thin walls which permit the exchange
of gases Oxygen and Carbon Dioxide. They
are surrounded by a network of capillaries,
into which the inspired gases pass. There
are approximately 3 million alveoli within an
average adult lung.
Diaphragm: The diaphragm is a broad band
of muscle which sits underneath the lungs,
attaching to the lower ribs, sternum and
lumbar spine and forming the base of the
thoracic cavity.
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
b. The breakdown of ATP into ADP + P:
Adenosine
P
Energy
P
P
Energy for cellular function
to contract working muscle
ATP Production at Rest
•ATP replenish with the use of Oxygen (Aerobic)
•Uses 75% Fats (lipids) and 25% CHO (glycogen)
•Wastes products are expired and breathed out
The ATP Molecule
• 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 system?
ATP-CP Energy System
• Replenishes ATP rapidly by breaking down Creatine
Phosphate releasing energy to reform ATP
• Short duration (<10 secs)
• 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), or when excising above AT (anaerobic Threshold)
• 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 predominantly use this system?
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
• Last for 10 seconds to 2 minutes
• 1 molecule- 3 ATP molecule
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 predominantly use this system?
Aerobic Glycolysis
• Replenishes ATP with the use of oxygen
• System works at rest and during very low intensity
exercise
• This form of energy primarily utilizes fats (75%) and
carbohydrates (25%) as fuel sources, but as intensity
is increased there is a switch from fats (25%) to
carbohydrates (75%)
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.
Energy Transfer Systems and Exercise
100%
% Capacity of Energy System
Anaerobic
Glycolysis
Aerobic
Energy
System
ATP - CP
10 sec
30 sec
2 min
5 min +
Energy Systems
• Describe how the three energy systems
interconnect when a person completes a 3km
run.
• Anaerobic (ATP-CP) system is used to start the
race. As the person continues to ‘take off’ at
speed, lactic acid begins to build up in the
muscle. After 2-3 minutes the aerobic system
kicks in and begins to remove lactate from the
muscle and fuel work needed for the remainder
of the run.
Energy Systems
• Give two examples of activities that would be
fuelled primarily by each energy system:
• Anaerobic (ATP-CP) system- Jumping up to
contest a jump ball in basketball.
• Lactic Acid System- Playing a game of touch or
basketball as they both require repeated
bouts of high intensity work.
• Aerobic System- Multi-sport race marathon
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
• Oxygen levels within the blood decrease which causes
increased diffusion at the lungs
• 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 intercostal muscles, diaphragm and other
muscle which aid the expansion of the thoracic
cavity 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 and so stimulates a higher rate of
energy metabolim.
• The bodys energy stores are slowly depleted
• Myoglobin 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.
Short Term Effects of Exercise
Responses to Aerobic Exercise (Points of Interest)
• The intensity and duration of exercise determines which
fuel source is used. Fat metabolism is a slow process and so
can only be used as fuel for exercise at less than 60% VO2
max.
• Carbohydrate is a much faster fuel source and so can be
used for exercise up to 80% (in trained individuals).
• Carbohydrate stores within the muscle and liver can fuel
exercise for up to 80 minutes. As carbohydrate stores get
lower, the body has to rely more and more on fat stores.
• The intensity of exercise which can be maintained drops as
fat cannot supply the required amount of energy.
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. Here are the changes which
must take place within the muscles,
respiratory system and circulatory system:
Long Term Effects of Exercise
• Circulatory System
• The cardiac muscle surrounding the heart gets
bigger, resulting in thicker, stronger walls.
• This allows an increase in heart volume. 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.
Long Term Effects of Exercise
• Circulatory System
• The density of the capillary beds in the muscles and
surrounding the heart and lungs increases as more
branches develop. This allows more efficient gaseous
exchange of Oxygen and Carbon Dioxide.
• The resting heart rate decreases in trained individuals
due to the more efficient circulatory system.
• The accumulation of lactic acid is much lower during
high-levels 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
• An increase in the number and diameter of capillaries
surrounding the alveoli leads to an increase in the
efficiency of gaseous exchange.
Long Term Effects of Exercise
Muscle
• Increased numbers of mitochondria (the cells powerhouse)
means an increase in the rate of energy production.
• 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 muscle,
and transported to the mitochondria.
• Muscles are capable of storing a larger amount of glycogen
for energy.
• Enzymes involved in energy production become more
concentrated and efficient to aid the speed of metabolism.
Mitochondria
• Mitochondria are the cell's power producers.
They convert energy into forms that are
usable by the cell.
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:
•
•
•
•
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Weight Training (focused on power)
Plyometrics (focused on power)
Interval Training (ATP-CP)
Circuit (Power and Agility based)
Aerobic Training (focused on baseline
fitness/endurance)