Lecture Exam 1 (part 3)

Question 1

How fatigue affects force production in a muscle (model)

Answer 1

task dependency model of fatigue

Question 2

Task dependency model of fatigue says this

Answer 2

what causes fatigue is dependent on the activity in which we are participating

Question 3

two hypothesis of the task dependency model of fatigue

Answer 3

accumulation hypothesis

depletion hypothesis

Question 4

accumulation hypothesis says this

Answer 4

build up of metabolic byproducts cause fatigue

es. lactate, Pi, ammonia

Question 5

depletion hypothesis says this

Answer 5

we run low on NT, or energy substrate and that causes fatigue

Question 6

This hypothesis is said to come into play in exercises that last 20-30 sec to 2-3 min

Answer 6

accumulation hypothesis

Question 7

by products in the accumulation hypothesis are these

Answer 7

substances produced while making ATP

lactate, Pi, ammonia

Question 8

average exhurtion for the accumulation hypothesis

Answer 8

70-80% max

Question 9

in the accumulation hypothesis ATP mostly comes from here

Answer 9

anaerobic glycolysis

carbohydrates are broken down to produce ATP and lactate

Question 10

Things that ties all the metabolic byproducts together in the accumulation hypothesis

Answer 10

build up of materials lowers the intracellular pH

Question 11

Lactate build up can cause fatigue in this ways (4)

Answer 11

Decrease in pH interfers with Ca++ from SR
Bond between Actin/Myosin is not as strong in low pH leading to less force production
Interfers with ATP breakdown due to low pH interfering with ATPase activity
interfers with ATP production, acidic pH interfers with rate of enzyme activity in glycolysis

Question 12

How Pi can cause fatigue (4)

Answer 12

Pi build up interfers with actin/myosin affinity
Pi interfers with Ca++ release from SR
Troponin-Ca++ binding affinity inhibitied
Interfers with Ca++ reuptake

Question 13

Where does Pi come from

Answer 13

ATP breakdown produces ADP + Pi + energy

Question 14

How Ammonia can cause fatigue

Answer 14

Reduces AP propagation along the sacrolema

Question 15

Where does ammonia come from

Answer 15

ADP builds up during exercise
ADP + AK -> ATP + AMP
AMP acted on by AMP deaminase
AMP + AMPdeaminase -> IMP + Ammonia

Question 16

THis is the largest factor affecting fatigue in the accumulation hypothesis

Answer 16

change in pH

Question 17

T/F: all of the accumulated substrates work together to cause fatigue

Answer 17

T

Question 18

How to modify acid/base chemistry to reduce fatigue

Answer 18

Sodium bicarb loading

exercise training

Question 19

how does sodium bicarb loading affect acid/base chemistry

Answer 19

increases proformance by acting as additional blood buffer

increases the bloods ability to buffer the acidic byproducts of metabolism

Question 20

how does exercise training affect acid/base chemistry

Answer 20

causes physiological shift to tolerate the added acidic stress placed on the body during training

Question 21

Two branches of depletion hypothesis

Answer 21

neural fatigue

energy substrate depletion

Question 22

caused by a total depletion of ACh at NMJ end bulbs

Answer 22

neural fatigue

Question 23

after enough constant contraction this will occur in a lab setting

Answer 23

neural fatigue

Question 24

depletion of the fuels used to produce ATP is an example of this

Answer 24

energy substrate depletion

Question 25

Fuels that can in theory be depleted

Answer 25

phosphogens carbohydrates proteins fats

Question 26

We cannot exercise enough to deplete these in energy substrate depletion

Answer 26

proteins | fats

Question 27

Phosphogen depletion describes the depeletion of

Answer 27

ATP and creatine phosphate

Question 28

These are used as the primary energy substrate for high intensity exercise

Answer 28

ATP and creatine phosphate

Question 29

How much activity do we have (time) with initial ATP resting stores

Answer 29

2-4 seconds

Question 30

where is ATP stored in the muscle

Answer 30

bound to myosin head

Question 31

T/F: ATP in the muscle can be fully depleted

Answer 31

F, but can reach a level low enough where it is not available for muscle contraction

Question 32

This energy substrate is stored in the cell and starts recharging process of ATP

Answer 32

phosphocreatine

Question 33

The stores of this in the muslce are the limiting factor of the duration of high intensity exercise

Answer 33

phosphocreatine | also ATP to a lesser degree

Question 34

depeletion of PC and ATp causes this

Answer 34

fatigue

Question 35

At max/near max exertion fatigue is caused by this

Answer 35

depletion theory (ATP, CP)

Question 36

at approx. 80% exertion, fatigue is caused by this

Answer 36

accumulation theory

Question 37

At lower exertion lvls fatigue is caused by this

Answer 37

depletion theory (glycogen)

Question 38

Benefit of enhancing PC stores increases this

Answer 38

duration of max intensity

Question 39

Two ways to increase PC stores in the body

Answer 39

high intensity exercise training | suppliment w/creatine

Question 40

this is the best form of supplimental creatine

Answer 40

creatine monohydrate

Question 41

directions on creatine loading

Answer 41

20g/day for 5-7 days 4-5g, 5-4x/day 3-5g/day after load also works at lower dose over longer period

Question 42

this percent of what we eat has PC

Answer 42

50-70%

Question 43

this AA combine to form creatine naturally

Answer 43

Gly Arg Met

Question 44

If PEG creatine you can do this

Answer 44

take half as much

Question 45

Some negative side effects of creatine may include

Answer 45

increase cramping or damage to organs | how scientific evidence to prove negative side effects

Question 46

Supplimentation of creatine does this

Answer 46

increases anaerobic exercise in repeated bouts | increase bone and muscle mass

Question 47

Mid intensity long term exercise causes fatigue thorugh this

Answer 47

glycogen depletion

Question 48

glycogen

Answer 48

polymer of glucose stored in muscle

Question 49

glycogen is primarily used as

Answer 49

an aerobic breakdown of carbs in endurance exercise

Question 50

This term is used when glycogen stores run out

Answer 50

hitting the wall

Question 51

this much energy is stored as glycogen in SM, and this much kcal will get you 1 mile

Answer 51

2000 kcal | 100 kcal

Question 52

this can increase glycogen stores

Answer 52

aerobic training | glycogen super compensation

Question 53

after glycogen is used up you use this for energy

Answer 53

aerobically burn FA