Exercise physiology

Question 1

what are the main methods of ATP synthesis

Answer 1

-Phosphocreatine (anaerobic)
-anaerobic glycolysis
- aerobic ATP synthesis

Question 2

describe the phosphocreatine (anaerobic) ATP synthesis system

Answer 2

• Phosphocreatine stored locally in the muscle
  -very fast and powerful (high intensity), but short duration
  -used in the initial 2-10 seconds of exercise

Question 3

describe the anaerobic glycolysis system for ATP synthesis

Answer 3

-glucose degrades to pyruvate
-quite fast and powerful
-10 seconds- 2 minutes duration
- during onset of exercise or high intensity exercise, pyruvate is converted to lactate (anaerobic pathway)

Question 4

describe the aerobic ATP synthesis system

Answer 4

• oxidative phosphorylation
  -occurs in mitochondria
  -can metabolise carbohydrates, lipids or proteins
  -used during moderate, sustained exercise
• oxygen is the final electron acceptor in the electron transport chain
  -most efficient and reliable system but is the slowest
• reliant on oxygen delivery to the cells

Question 5

define oxygen uptake

Answer 5

the measure of a person’s ability to take in oxygen and deliver it to the working tissues, and the ability of the working tissues to use oxygen

Question 6

what happens to oxygen uptake during exercise

Answer 6

oxygen uptake increases to be able to deliver more oxygen to working muscles

Question 7

define oxygen delivery

Answer 7

the rate of oxygen transport from the lungs to microcirculation

Question 8

equation for oxygen delivery

Answer 8

D02 = arterial oxygen content (oxygen bound to haemoglobin + oxygen dissolved in plasma) + cardiac output

Question 9

name some factors which influence oxygen uptake

Answer 9

muscle blood flow
capilary density
mitochondrial density
affinity of haemoglobin for oxygen (bohr effect)
muscle mass

Question 10

describe the response of the respiratory system to exercise

Answer 10

• minute ventilation increases (8L/min at rest, 200L/min during exercise)
• depth of breathing increases before rate of breathing
• respiratory muscles increase their use
  -in healthy individuals, there will be a ventilatory reserve existing after maximal exercise

Question 11

describe the response of the cardiovascular system to exercise

Answer 11

• Cardiac output increases up to 5 times during exercise
  -Heart rate increases linearly with work rate
• Stroke volume increases rapidly at first then plateaus

Question 12

what cardiovascular factor is the limiting factor to oxygen delivery in healthy individuals

Answer 12

cardiac output

Question 13

describe the normal response of the coronary circulation to exercise

Answer 13

-coronary arteries recieve blood during diastole
- increased flow to coronary arteries
-vasodilation of coronary vessels
-

Question 14

describe the response of the peripheral circulation to exercise

Answer 14

-blood flow redistributed from non-vital organs to the muscles
-blood flow to skin increases for heat dissipation
-arterioles vasodilate

Question 15

describe the physiological response to endurance training

Answer 15

• stroke volume increases
  heart rate increases
• systolic blood pressure decreases
  capillary density increases
  mitochondrial density increases

Question 16

desrcibe the physiological responses to High Intensity Interval Training

Answer 16

• increased peak VO2 max
• decreased systolic and diastolic blood pressure
• increased cardiac function