Short term/Immediate responses to physical activity?
- increased heart rate
- stroke volume increases
- increased blood pressure
- increased cardiac output
- increased respiratory rate/ventilation
- perspiration/temperature regulation
- selective redistribution of blood
additional:
- increased oxygen consumption
- increased rate of gas exchange in lungs
- increased Arteriovenous difference
Why does blood pressure increase with exercise?
Result of blood being pumped by the heart with greater force -> more pressure being applied to artery walls.
Why does heart rate increase with exercise?
To provide a more rapid supply of blood (containing oxygen, nutrients and fuel) to the working muscles. Increase in HR ->directly proportional to workload.
At rest fit male= average 60bpm, during exercise max HR= 220bpm - age.
Why does cardiac output increase with exercise?
The muscles require more fuel and oxygen in order to produce energy for contraction. (oxygen and fuel carried to muscles via blood)
To provide increased amounts of fuel and oxygen -> more blood must be circulated to muscle tissues more quickly. This archived via greater output of blood/total blood flow.
CARDIAC OUTPUT = total amount of blood pumped every minute.
At rest-> approximately 5L per minute
during exercise -> up to 35L (fit male)
Why does stroke volume increase with exercise? and What is stroke volume?
Stoke volume=the amount of blood the heart pumps out with each beat.
Stroke volume increases due to more venous blood being returned to the heart from muscles. -> increase in strength of contraction of heart leads to -> heart fills with more blood and blood pumped out with greater force.
at rest fit male = approximately 80ml during exercise up to 180ml.
What is selective redistribution of blood and why does it occur in response to exercise?
Selective redistribution=CV system redistributes more of the blood to working muscles, and less of it goes to other body parts/organs which are not working (ie-digestive system).
Arteries taking more blood to working muscles will open up (dilate) to allow more blood flow to muscle. arteries taking blood to non-active areas of the body contract to reduce blood flow. This increases amount of blood available to working muscles.
What is temperature regulation and explain how it assists cooling the body during exercise?
Temperature regulation= the body’s ability to control and regulate heat gained by working muscles, or heat lost.
To avoid overheating, blood acts as temperature regulator -> removes heat from within the body to the skins surface, where evaporation of sweat (perspiration) assists in cooling the body.
Why does respiratory rate/ventilation increase with exercise?
When you exercise, your muscles work harder meaning your body uses/requires more oxygen and produces more carbon dioxide. To account for this, the number of times you need to breathe in and out per minute increases.
Tidal volume=amount of air that flows in/out of the lungs in one respiratory cycle (inhalation and exhalation)
What is AV02 difference?
Arteriovenous oxygen difference= the difference in the amount of 02 available in the arterial blood Vs venous blood, that can be extracted by the muscle tissue.
also The difference in the amount of oxygen delivered to muscle tissue, compared to the amount of oxygen leaving the muscle tissue.
It is an indication of how much o2 is removed from the blood in capillaries as the blood circulates the body.
What is VO2 max?
The maximum amount of oxygen that an individual can utilise during exercise.
OR
an Individual’s capacity for aerobic ATP production.
What are the 12 long term adaptations to training?
1.increased cardiac output
2. decreased heart rate
3. blood pressure appropriates normal (decreases)
4. Increased blood volume and hemoglobin
5. increased stroke volume
6. increased maximum oxygen uptake (VO2 max)
7. capillarisation
8. increased oxygen exchange/extraction
9. muscle hypertrophy
10. increased flexibility
11. increased aerobic and anaerobic capacity->greater ATP-CP capacity
12. more efficient respiratory rate/ventilation
Describe how training leads to LTA (long term adaptation) of muscle hypertrophy.
- result of increase in the number and size of myofibrils per muscle fibre, increased amounts of myosin and actin and therefore increase in size of muscle fibres.
- leads to increased force that muscle can exert
- speed of muscle contraction also increased
- changes to muscles fibres depends on the type of training undertaken - aerobic results in hypertrophy of slow-twitch, and anaerobic hypertrophy of fast twitch.
Describe how training leads to LTA (long term adaptation) of decreased heart rate, increased stroke volume and cardiac output.
- increased size/strength of heart (hypertrophy) due to regular exercise.
- heart can pump more blood (^cardiac output) with each beat (^stroke volume) and rest for longer periods between beats.
- resting and exercise heart rate of trained athletes lower than untrained individuals
- maximum heart rates achieved after longer period of intense exercise for trained athletes.
Describe how training leads to LTA (long term adaptation) of increased blood volume and haemoglobin.
- result of increase in plasma and red blood cell volume stimulated by exercise
- means more oxygen can be transported from the lungs to working muscles and co2 removed more rapidly
-effectiveness of oxygen delivery/waste removal improved
Describe how training leads to LTA (long term adaptation) of increased oxygen extraction.
- greater quantity of o2 extracted from circulatory blood as a result of;
-increased cardiac output - an enhanced capacity of the muscles to extract oxygen (due to an increased number of capillaries surrounding muscle fibres to facilitate more rapid gas exchange)
Describe how training leads to LTA (long term adaptation) of decreased or ‘NORMAL’ blood pressure.
- with training, overtime the heart will not have to work as hard to pump blood around the body. (due to strengthening of the heart muscles which lead to increased cardiac output)
-decreases both systolic and diastolic blood pressures
Describe how training leads to LTA (long term adaptation) of a more efficient respiratory rate/ventilation.
- greater efficiency of muscles controlling inspiration/expiration (ie-diaphragm)
- and a slight increase all respiratory volumes (ie- tidal volume=amount of air that moves in and out of the lungs with each respiratory cycle -ie one breath)
- means that more air can be breathed in with each inspiration, making more o2 available for working muscles
- as well as more co2 removed from body lungs
- onset fatigue will be delayed
Describe how training leads to LTA (long term adaptation) of an increase in maximum oxygen uptake (vo2 max).
- lungs and intercostal muscles become stronger leading to more efficient breathing
Describe how training leads to LTA (long term adaptation) of capillarisation.
capillarisation= the formation of a network of capillaries to a part of the body that increases blood supply to the area; is increased by aerobic exercise. A high muscle capillary density means a large muscle-to-blood exchange surface area, short oxygen diffusion distance and therefore a greater exercise capacity.
- intensive training requires more fuel to the working muscles (o2 carried in the blood). Therefore, capillarisation takes place - the formation of capillary networks that increase in an area that is working hard.
Describe how training leads to LTA (long term adaptation) of increased oxygen exchange.
Describe how training leads to LTA (long term adaptation) of faster recovery rate after exercise.
- result of increased size and number of vessels carrying blood to and from working muscles
- means muscle shave a plentiful source of o2 and a higher waste removal rate
Describe how training leads to LTA (long term adaptation) of a greater anaerobic capacity.
- combined result of ;
-increased levels of ATP and CP stores in muscles. means more immediate energy is available to working muscles. - increase in quantity of key enzymes that control anaerobic phase of glycogen to ATP production (help to break down glucose and glycogen (for energy)
- increased capacity to generate high levels of blood lactate during maximal exercise.
Also decrease is blood lactate concentration- meaning intense/higher speed activities can be performed for longer before the onset of fatigue
Describe how training leads to LTA (long term adaptation) of a greater aerobic capacity.
- due to improved oxygen supply to muscles (capillarisation & improved efficiency of system)
- increased ability to mobilize, deliver and use fat for energy (during submaximal exercise) and increased ability to oxidise carbohydrates (during maximal exercise)
- muscles able to work for longer, hence greater aerobic endurance
which energy system has the most rapid supply of energy?
ATP-CP
