exercise metabolism condt - week 2

Question 1

for carbohydrates state :
energy source
stored from
stored where
breakdown process

Answer 1

glucose (monosaccharide)

glycogen (polysaccharide)

liver and muscle

gylcogenolysis

Question 2

for fats state :
energy source
stored from
stored where
breakdown process

Answer 2

fatty acids

tryglycerides

muscle and adipose tissue

lipolysis

Question 3

for protein state :
energy source
stored from
stored where
breakdown process

Answer 3

amino acids

gluconeogenesis in liver

can be converted into metabolic intermediates

Question 4

an RER over __ shows working hard + high effort

Answer 4

1.15

Question 5

what is RER ?

Answer 5

respiratory exchange ratio

Question 6

what must RER be measured during ?

Answer 6

steady state exercise

Question 7

what does an RER of 0.7 mean ?

Answer 7

fats oxidised and used at fuel

Question 8

what does an RER of 1 mean ?

Answer 8

carbs oxidised and used as fuel

Question 9

at low intensity exercise what is used as fuel ?

Answer 9

fat

Question 10

at high intensity exercise what is used most as fuel ?

Answer 10

carbs

Question 11

why does metabolic fuels change due to change in exercise metabolism ? (2)

Answer 11

recruitment of fast muscle fibres

increasing blood levels of epinephrine stimulates glycolysis and lactate production

Question 12

in long duration exercise what fuel is used more ?

Answer 12

higher % fat

Question 13

what is beta oxidation ?

Answer 13

process of oxidisation fatty acids to acetyl-coA

Question 14

if glycogen is depleted during prolonged high intensity exercise what is decreased as a result ? (2)

Answer 14

decreased glycolysis
- reduced production of pyruvate

decreased kerbs activity

Question 15

what % of VO2 max is optimal for fat oxidation ?

Answer 15

60%

Question 16

and the beginning of exercise, what is released to trigger glygenolysis?

Answer 16

adrenaline

Question 17

At 85% VO2 max what is the main fuel source?

Answer 17

Muscle glycogen

Question 18

Why is there an increased rate of glycogenolysis during high intensity ?

Answer 18

Due to recruitment of fast twitch fibres and increase in blood epinephrine levels

Question 19

What is a lactate threshold ?

Answer 19

Point at which blood lactic acid rises systematically during incremental exercise

Question 20

Where does the lactic acid threshold appear in untrained and trained athletes ?

Answer 20

50-60% VO2 max in untrained

65-80 % in trained

Question 21

What are some reasons for the lactate threshold (4)

Answer 21

Accelerated glycolysis

Recruitment of fast twitch fibres during intense and rapid exercise

Reduced rate of lactate removal from the blood

Low muscle oxygen

Question 22

How does accelerated glycolysis lead to lactate threshold ?

Answer 22

NADH produced faster than shuttled to mitochondria

This leased to pyruvate forming with unshuttled H+ forming lactate

Question 23

How does recruitment of fast twitch fibres lead to lactate threshold ?

Answer 23

LDH isozyme in fast fibres has greater affinity to attach to pyruvate which forms lactate

Question 24

How does reduced rate of lactate removal lead to lactate threshold ?

Answer 24

Blood flow to muscles are prioritised over the tissues responsible for removing lactate e.g. liver

Question 25

What causes delayed soreness ?

Answer 25

Microscopic tears in muscles fibres
- slow cascade of biochemical events leasing to inflammation and edema in muscle

Question 26

What is the cori cycle ?

Answer 26

Cycle of lactate/glucose between muscles/liver to be reused as a fuel source in another tissue