Lesson 2 Exercise and Metabolism

Question 1

What does VO2 reflect?

Answer 1

level of energy expenditure

Question 2

How is VO2 measured?

Answer 2

L/min or mL/min

Question 3

What is VO2max?

Answer 3

maximal capacity of the CV system to deliver oxygenated blood to dynamically working muscle

Question 4

Where does the body store most of its glycogen in percentage?

Answer 4

muscle: 79.5%

liver: 20%

plasma: <0.5%

Question 5

What does muscle glycogen do?

Answer 5

provides fuel for muscular contractin

Question 6

What does liver glycogen do?

Answer 6

provides temporary storage of glucose and helps maintain glucose levels during fasting and exercise

Question 7

How is fat stored in the body?

Answer 7

triglycerides

Question 8

Where is fat stored in the body?

Answer 8

• 95% adipose tissue
• plasma
• muscle
• liver

Question 9

Where is protein stored in the body?

Answer 9

• skeletal muscle: 50-75%
• plasma membranes
• globular proteins
• free amino acids in blood
• no amino acid reserves in body

Question 10

What is resting metabolic rate?

Answer 10

rate of energy expenditure which is require at complete rest for cell function, temp reg, and maintaining systems

Question 11

What is the typical RMR?

Answer 11

1100-2500

Question 12

What are the body’s readily available fuel sources?

Answer 12

CHOs and FATs

Question 13

Which fuel systems are used at high, medium, and low intensity?

Answer 13

high: PCr
medium: glycolysis
low: aerobic

Question 14

What do the catecholamines (epinephrine and norepinephrine) do?

Answer 14

• increase FFA supply by stimulating lipolysis
• stimulate gluconeogenesis and glycogenolysis in liver
• stimulate glycogenolysis in SM
• inhibit insulin release and stimulate glucagon

Question 15

What does growth hormone do?

Answer 15

• increase FFA supply stimulating lipolysis
• stimulate gluconeogenesis and glycogenolysis in liver
• attenuates glucose uptake in SM
• indirectly promotes growth and repair of SM

Question 16

What does cortisol do?

Answer 16

• stimulates gluconeogenesis and glycogenloysis in liver
• attenuates glucose uptake in SM
• increase FFA supply by stimulating lipolysis in adipose tissue
• aids in recovery and repair after strenuous exercise

Question 17

What does glucagon do?

Answer 17

• stimulates gluconeogenesis and glycogenolysis in the liver
• increases FFA by stimulating lypolysis

Question 18

What does insulin do?

Answer 18

• stimulates the uptake of glucose by muscle, fat, and liver
• inhibits lipolysis in adipose tissue
• inhibits glucose release in liver

Question 19

Which hormones increase with increase in exercise intensity and duration?

Answer 19

catecholamines, growth hormone, cortisol, glucagon

Question 20

Which hormone decrease with increase in exercise intensity and duration?

Answer 20

insulin

Question 21

What happens as exercise duration increases?

Answer 21

more fat and less CHO burned, more from plasma sources and not endogenous sources

Question 22

What happens as exercise intensity increases?

Answer 22

greater proportion of ATP derived from glycolysis

Question 23

Which energy pathways are relied upon during low and high intensity exercise?

Answer 23

low: aerobic (CHO and fat)

high: anaerobic

Question 24

Which hormones stimulate and inhibit lipolysis?

Answer 24

stimulate: growth hormone, cortisol, testosterone

inhibit: insulin

Question 25

How do the affect of catecholamines change with exercise intensity?

Answer 25

low/moderate: small increase in epinephrine mobilizes FFA to fuel aerobic metabolism high: large increase in epinephrine inhibits FFA mobilization, making glucose main source of energy

Question 26

When does fat oxidation tend to be the highest?

Answer 26

50-60% VO2max

Question 27

Why does fat oxidation decrease with exercise intensity increasing?

Answer 27

- increased chatecholimine concentration cause shift from FAT and CHO - increased signal to stimulate glycolysis and glucose use in the muscle

Question 28

What protein facilitates blood glucose uptake in skeletal muscle?

Answer 28

GLUT

Question 29

Where is GLUT1 found and does it require insulin?

Answer 29

many cells and no

Question 30

Where is GLUT2 found and does it require insulin?

Answer 30

in liver and no

Question 31

Where is GLUT4 found and does it require insulin?

Answer 31

in muscle and adipose cells and yes

Question 32

Can glucose be transported to other structures once in muscle?

Answer 32

no

Question 33

What is insulin resistance?

Answer 33

impaired ability of insulin to activate GLUT4 receptors, resulting in hyperglycemia

Question 34

How is plasma glucose maintained?

Answer 34

- increasings reliance on FFAs - attenuating glucose uptake into muscle - obtaining glucose from the liver

Question 35

What happens at exercise initiation to ATP and O2 supply?

Answer 35

ATP production changes instantly while O2 does not right away creating a O2 deficit

Question 36

What are factors contributing to decreased oxygen deficit in trained individuals?

Answer 36

- increased mitochondrial content - greater oxygen storage in muscle - greater oxygen delivery to muscle

Question 37

What is EPOC?

Answer 37

excess post-exercise oxygen consumption

Question 38

What are the fast portion of EPOC characteristics

Answer 38

- 2 to 3 min - O2 is used to restore ATP and PC to resting levels - muscle and blood O2 stores or replenished

Question 39

What are the characteristics of the slow portion of EPOC?

Answer 39

- energy to support increased HR and respiratory rate - reduction of body temp to normal - oxidation of excess lactate back to glucose - elevated chatecholomines contribute to increased metabolic activity

Question 40

What is the principle of specificity?

Answer 40

states that sports training should be relevant and appropriate to the sport for which the individual is training in order to produce a training effect

Question 41

What are the chronic effects of sprint training?

Answer 41

small increase in resting ATP, CP, and free creatine in muscle increase in creatine kinase activity useful for short, high intensity efforts

Question 42

What are the chronic effects of exercise?

Answer 42

- increased muscle glycogen stores - increase max enzyme activity

Question 43

What are the chronic effects of training?

Answer 43

- modest increases in IMTG - substantial increase in mitochondrial volume and muscle capillarization

Question 44

What are the effects of training on fat oxidation during exercise?

Answer 44

causes a shift to use more fat and less CHO at sub maximal exercise intensities - ^ in fat sensitivity enzymes - ^ in fat mobilization enzymes - increase in number/activity of fatty acid transporters

Question 45

What are the effects of endurance training on hepatic glucose output?

Answer 45

- increase in liver glycogen storage - increase in gluconeogenic capacity - enhances insulin sensitively

Question 46

What are the effects of training on blood lactate response to exercise?

Answer 46

- increases the workload at which the lactate threshold and OBLA occur (less lactate produced at same workload

Question 47

What are the factors that influence a decrease in blood lactate after endurance training?

Answer 47

- less reliance on CHO oxidation - increased mitochondria - greater removal of lactate to tissues

Question 48

What is exercise economy?

Answer 48

absolute energy required for a specific power output or obtained velocity

Question 49

How is exercise economy measured?

Answer 49

oxygen consumption or energy expenditure

Question 50

What are the physiological factors that improve exercise economy?

Answer 50

- increased capacity to resynthesizes ATP via Ox Phos - slow twitch fiber more oxidative, so more = more economical

Question 51

What are the biomechanics factors that improve exercise economy?

Answer 51

- improved coordination of muscle recruitment - increased elastic energy

Question 52

How does exercise economy affect patients clinically?

Answer 52

may limit patient's ability too perform many activities of filly living