Chapter 7,8,9,18 Flashcards Preview

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Flashcards in Chapter 7,8,9,18 Deck (57):
1

how does lactate threshold differ in trained vs untrained

untrained at 55% Vo2max
trained at higher %

2

what are the two substances pyruvate can go to

lactate (w/lactate dehydrogenase) and acetyl coa (w/pyruvate dehydrogenase)

3

what is the definition of lactate threshold ?

% Vo2max when blood lactate starts accumulating

4

what will pyruvate become at 25, 55, and >55% VO2 max ?

at 25%, most pyruvate goes to Acetyl CoA
sufficient O2 to do this work
at 55%, increasing carb consumption, more pyruvate being formed, more of it goes to lactate
at >55% lactic acid accumulation, going to different organs but also a larger percentage of acetyl coA

5

what is the traditional explanation of blood lactate accumulation ?

relative tissue hypoxia. with imbalance between hydrogen release (from NADH) and oxidation, the hydrogens will instead bind to pyruvate to become lactate

6

where does lactate go at rest or in moderate exercise ?

oxidizes, converts to glucose, or synthesizes to amino acids (no net lactate accumulation)

7

list three factors that contribute to a higher lactate threshold

genes (fiber type, blood flow)
local training adaptations that favor less lactate production
greater rate of lactate removal

8

list 5 training adaptations in aerobic exercise

increase in mito size and number
increase in protein synthesis (for oxidative enzymes)
increase in effectiveness of these proteins, which yields more H+ and therefore more ATP
less lactic acid buildup due to better lactic acid removal
increased capillary density

9

why does it take time to reach steady state VO2 ?

time constraint for cells to use O2 being delivered.

10

how do untrained vs trained differ in reaching steady state Vo2 ?

trained reach it faster

11

what does the steady state represent ?

plateau in O2 consumption curve (balance between energy required and ATP produce)
no lactate accumulation during steady state.

12

what is oxygen deficit ?

the area from 0 to steady state
trained has smaller deficit than untrained

basically difference between total O2 consumption and the O2 that would have been consumed if we had SS all along.

13

what are the two factors that good endurance performance depends on ?

ability to deliver O2 and ability to use O2

14

what happens after you've reached Vo2 max and you keep going ?

using up any glycogen left for 15-20s

15

how does O2 consumption increase with each steady state "hill" ?

at first it augments rapidly, but then as you increase, it will barely increase, that's when you know the max is near

16

what are the 5 factors that need to be integrated for a good oxygen system ?

aerobic metabolism, pulmonary ventilation, hemoglobin concentration, blood volume and cardiac function, peripheral muscle and blood flow.

17

how does pulmonary ventilation affect the oxygen system.

Va/Q ratio = alveolar ventilation / pulmonary blood flow

should be 0.8
low capability of Va = low ability to reach an elevated Vo2

18

is a Va/Q of 0.8 always good ?

nope. sometimes the ratio is ok but the numerator and denominator are both very low (like in cardiac + pulmonary disease)

19

what is the Fick equation ? what does it imply ?

Vo2= Q x (a-v O2 difference)max

Q= cardiac output (HRmax x SVmax)

20

what is normal and max stroke volume? what does it depend on ?

normal 60-70 ml/beat
max 120-140 ml/beat

depends on left ventricle contraction

21

how does blood hemoglobin concentration affect oxygen use and transport

better capacity to transport O2 to tissues

22

what are the norms for Hb

women 13-15 g Hb/100 ml blood
men 15-17 g Hb/100 ml blood

23

what 2 illnesses cause low Hb

anemia (women 12, men 14)
multiple myeloma 8-10g Hb / 100 ml blood
lead to fatigue

24

what will happen with high Hb

polycythemia
17-20 g Hb/100 ml blood

when body is under high stress eg high altitude, increased blood viscosity

25

where can pyruvate get converted to glycogen ?

ONLY IN THE LIVER FOR THE LOVE OF KANYE

26

what tissues take up lactate

ALLLLLL OF THEM

27

what is EPOC

excess post exercise oxygen consumption

28

in mild aerobic activity, how much time does complete recovery take ?

2-4 min (fast component)

29

in moderate to heavy activity, what are the two components in EPOC ?

fast
and slow

30

what are the three factors contributing to the slow component in EPOC ?

- thermic effect (temperature elevation, increased metabolic effect)
- hormone levels (E, NE) go to baseline after 30-40
- lactate removal

31

how fast O2 levels go to normal depends on two things what are they ?

intensity and duration of exercise.

32

how long can recovery O2 consumption last for (due to the slow component) in EPOC in supramaximal exercise ?

1hr

33

what 7 factors that contribute to EPOC ?

1- resynthesizing ATP and PCr (payback to exercising muscles)
2- resynthesizing lactate to glycogen to restore levels
3- oxidizing the rest of the lactate
4- restoring O2 and myoglobin to blood
5- restore thermogenic effect
6- restore catecholamine levels
7- restore physiologic functions like HR

34

what kind of recovery is best to restore blood lactate concentration to normal during EPOC ?

active recovery at 35-65% Vo2max
any higher and you'll be producing more lactate, so there's just going to be more to get rid of

35

how do you find carb RQ ?

C6H12O6 + 6 O2 --> 6 CO2 + 6 H20

6 CO2/6 O2= 1.00

36

how do you find fat RQ (eg palmitic acid)?

C16H32O2 + 23 O2 --> 16 CO2 +16 H2O

16 Co2/23 O2 = 0.7

37

what is the approximate RQ for protein ?

0.82

38

at rest what is the approximate ml/ min of O2 and CO2 ?

215 ml/min LCO2 and 250 ml/min L O2

RQ= 0.86

39

how is RQ different from RER ?

RER is used when the ratio is bigger than 1 because the CO2 produced is higher than what metabolism is producing. (eg in hyperventilation).

40

explain where and how, in intense exercise or respiratory maneuvers, more CO2 appears

H-lactate + NaHCO3 (sodium bicarbonate) --> NaLa + H2CO3

H2CO3 is carbonic acid, a strong acid that goes to the pulmonary capillaries in the blood and in a special reaction that can occur only there H2CO3--> H2O + CO2 w/ the help of carbonic hydroxylase

41

5 factors that affect total energy expenditure

1 physical activity
2 diet induced thermogenesis
3 calorigenic effect of food on metabolism
4 climate
5 pregnancy

42

to measure basal metabolic rate, what would we have to do ?

lights off
no falling asleep
no moving
1 hr

43

is resting metabolic rate a relative value ?

yessssssssssssss

44

what is bigger BMR or RMR

ALLLLWAYS BMR

45

what is 1 MET

3.5 ml O2 /kg*min
or 5 kcal/ L O2

46

what are the two organs that consume the most oxygen

liver and brain

47

what is diet induced thermogenesis

results energy required to digest and stuff + energy from SNS activation and stimulation

48

does physical activity increase diet induced thermogenesis

YES

49

how does climate affect total daily energy expenditure ?

RMR higher in tropical than in cold countries

50

how does pregnancy affect total daily energy expenditure ?

added energy cost from walking etc due to additional weight transported.

51

what is avg kcal expenditure for men and women

man 2900
woman 2200

52

what are the 4 characteristics of fast twitch muscle fibers

type II
- high capacity for transmission of AP
- high myosin ATPase activity
- rapid Ca2+ release and uptake by sarcoplasmic reticulum
- high rate of crossbridge turnover

53

what are the 4 characteristics of slow twitch muscle fibers

- low myosin ATPase activity
- slow calcium handling ability
- not as good glycolytic pathway
- large and numerous mitochondria

54

what is PGC-1alpha responsible for ?

promotes mitochondrial biogenesis, fatty acid oxidation, and hepatic gluconeogenesis. therefore if it's activated in genes there will be an increased proportion of type I muscle fibers

55

what does a skeletal muscle fiber consist of ?

75% water
20% protein
the rest is stuff

56

a muscle's hydrogen consumption increases up to ... times in exercise

70

57

explain how a muscle biopsy will identify type I and II fibers

take biopsy of vastus lateralis muscle
from there, stain with different pH
pH 4 will show type II fibers due to myosin-ATPase activity
pH 10 will show type I fibers