Effect Of Single Bout Of Exercise On Body Organ.(Acute) Flashcards
Physical activity is defined as
An all inclusive term that refers to the
Expenditure of energy brought about by bodily movement via skeletal muscles.
Difference btwn physical activity and exercise
Is that exercise is structured activity specifically planned to develop and maintain physical fitness…
Uses of exercise are?
Enhancing growth and development
Preventing aging
Strengthening muscles
& Cardiovascular system
Honing athletic skills
Weight loss or maintenance
Improving health
Leisure.
Note:
Aerobics (walking , jogging running , dancing )
Anareobic( wight training , sprinting )
Strength training ( lunge , bench press , push up)
Calisthenics ( dips , fartlek , circuit training )
Yoga
Classification of exercise ?
Acute &
Chronic
What is chronic exercises ?
Can be described as repeated amount of bouts of exercise during a short or long term period of time..
Physical conditioning is a result of chronic exercise, brought about by the adaptation of the body and its various systems to an exercise program.
Acute exercise can be defined as ?
Single bout of exercise.
Body response to it are short term in nature because they are only present during activity or exercise.
The body returns to its pre- exercise levels and these responses are reversed.
Note :
Any type of exercise requires energy for muscle contraction ..
The exercise intensity and duration determines the energy system to be used for generation of ATP.
A quick burst of muscular contraction for sprinting and wight lifting needs a phosphagen pathway.
400 meter athlete need a Lactic acid system
A marathoner needs an aerobic system
Respiratory system response to acute exercises
- increased tidal volume
*Increased breathing rate
What is tidal volume ?
Is a measure of the amount of air a person inhales during a normal breathe.
Note: both aerobic and anaerobic exercise increases tidal volume because oxygen is depleted, thereby triggering a deeper tidal volume to compensate.
What is Breathing rate?
The amount of oxygen used up by the cells of the body
Note: during exercise the cells respire than usual using more glucose and oxygen so they are supplied with new glucose and co2 is taken out.
During exercise the breathing rate will increase from about 15 breathe to about 40 breathe
And VO2 is the measure amount of oxygen taken in and used up by the body
The most commonly used measure of respiratory function with exercise is ?
VO2 ( volume of oxygen intake)
What is VO2 ?
Refers to the measure of the amount of oxygen taken up and used by the body.
Cardiovascular response to acute exercises ?
(4)
- Heart rate anticipatory response
- Increased blood pressure and heart rate.
*Increased stroke volume
*Increased cardiac output.
1) Explanation of heart rate anticipatory response ?
The resting heart rate for an average normal person is about (60-80bpm) and can be very low for an elite athlete (24-40 bpm).
Just before somebody is about to participate in an activity , the body will release chemicals such as epinephrine and adrenaline into the body which will increase the heart rate .
2) Explanation on increased blood pressure and heart rate?
Blood pressure against the walls of the artery
During exercise the blood pressure will increase as well as the heart rate .
These are prevented from going too high by some specific mechanism
3)What is stroke volume ?
Stroke volume is the amount of blood ejected per beat from the left ventricle.
Measured in ml/beat.
Explanation on increased stroke volume ?
SV increases proportionally with exercise intensity
In untrained individuals SV rest is between 50- 70 ml/beat
During intense physical activity SV increases up to 110-130ml/beat
In elite athletes resting SV averages between 90-110ml/beat, increasing to as much as 150-220 ml/beat.
4) Explanations on Increased cardiac output?
Cardiac output= heart rate × stroke volume
During strenuous exercise cardiac output rises dramatically
In untrained individuals, cardiac output goes up to fourfold
From 5L/min to 20L/min
In trained athletes it may be up to six or eight times , reaching as much as 40L/min
Because oxygen delivery by the cardiovascular system is the primary factor for determining exercise tolerance,
Trained are more capable of more strenuous exercises.
What are the Muscular responses to acute exercise ?
(5)
1.Increased muscle blood flow
2.Increased motor unit and muscle fibre recruitment
3.Increased muscle pliability
4.Increased range of motion
5.Muscle fibre tear
- Explanation on increased muscle blood flow
At rest
Skeletal muscle receive less than a fourth of the cardiac output.(about 1.2L/min)
During exercise a shift in blood flow takes place
During exercise in highly trained athletes combination of increased cardiac output and vasodilation
can increase blood flow to exercising muscle to more than 22L/min.
The relative distribution to tissue also shifts
About 88% of cardiac output is diverted to the exercising muscles from 21%.
- Explanation on increased motor unit and muscle fibre recruitment?
Motor unit = a motor neuron and muscle fibre it stimulates
During exercise the brain recruits more motor units
So when the body requires more strength /power/ force there will be an increase in the number of motor unit recruited.
Increase in frequency of messages will increase the force produced in the muscle
All or none law : a motor unit either contracts fully or it does not contract
Contraction requiring maximum force will recruit more motor unit than the one requiring less force.
- Explanation on increase in muscle pliability?
During short exercise
Muscle pliability is increased due to body heat generation
This will reduce the likelihood of muscular injuries
Important to warm up before going into main exercises.
4.Explanation on Increased range of motion ?
Acute exercise yields a warmer and thinner joint synovial fluid
Thereby allowing a more efficient movement
Muscle fibres and the connective tissues become more elastic which would allow them stretch easily …
5.Explanation on muscle fibre tears ?
The muscle fibre micro tears as a result of acute exercise.
These tend to pull against one another during intense exercise
This is why we ache after engaging in strenuous exercise
6.Response of acute exercise on nervous system
Improved cognition
Improved emotional state
Explanation on improved cognition?
The immediate effect of exercise are on the neurotransmitters.
This causes complex signals to pass through the neurons of the brain.
This alerts the brain for learning and makes them retain information easily
Explanation on improved emotional state?
Acute exercise has been shown to enhance mood and emotional states….
During intense exercise breathing rate moves from 15 breathe per minute to ?
40-50 breathe per minute
