Exercise Flashcards

1
Q

What is a hyperinsulinemic euglycemic clamp?

A

Inject more insulin than normal levels, injecting glucose (clamped at app. 5 mmol/L)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the glucose infusion rate (GIR)?

A

The glucose infusion rate at which the blood glucose level is stable at app. 5 mmol/L. GIR is given in mg/min/kg
High: insulin sensitive
Low: less insulin sensitive/insulin resistant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which are the three metabolic pathways for ATP production?

A

Creatin kinase, glycogenolysis/glycolysis, and oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is the relationship between shortening velocity and force?

A

Inverse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does resistance training improve?

A

Both force and power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some adaptation with resistance training?

A

Increased muscle fiber size (diameter), especially type II, but also type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does aging affect muscle fiber size?

A

Reduces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is improved with endurance training?

A

VO2 max
Time to exhaustion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the blood parameters change during endurance exercise?

A

Blood glucose reduction, blood lactate increation, blood FFA increation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What substrates are utilized during different intensities of endurance exercise?

A

High: sugar
Medium: sugar and fat
Low: fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the relationship between sugar and fat utilization during exercise.

A

At low intensity, sugar and fat are utilized app. equally, at high intensities sugar are the substrate primarily used for utilization.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the RER, and what can it be used for?

A

Respiratory exchange ratio, the ratio between fat:sugar utilized
At steady state, RER = RQ (respiratory quotient)
RER is what can be measured, RQ is in tissue

RER = VCO2/VO2
= 1 : CHO
= 0.7 : lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does adrenalin stimulate during exercise?

A

Glycogeneolysis, gluceneogenesis, and lipolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does glucagon stimulate during exercise?

A

Glycogeneolysis, gluceneogenesis, ketogenesis
Inhibits: glucogen synthesis and glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does exercise affect the plasma substrate of glucogon, adrenalin, insulin, and GH?

A

Increases: glucagon, adrenalin and GH
Decreases: insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are myokines believed to be involved in organ cross-talk?

A

IL-6 (myokine) from muscle –> lipolysis and gluconeogenesis in liver and adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What can be limiting factors during endurance exercise?

A

Muscle fatigue: hypoglucemia, glycogen depletion, Ca2+ handling and K+ homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is K+ homeostasis involved in muscle fatigue during prolonged exercise?

A

Na+/K+ pump cannot keep up with the production of K+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How can muscle fatigue be manipulated?

A

Initial muscle glucogen determines duration –> supercompensation: muscle glucogen enhanced by prior exercise and CHO intake or by prior exercise + low CHO intake followed by high CHO intake (psychologically tough)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are improved with exercise training regarding VO2max?

A

Pulmonary ventilation and stroke volume => cardiac output => VO2 max
Also increase plasma volume and heart size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the limiting factor of VO2 max?

A

The pumping capacity of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is the relationship between max O2 delivery and VO2?

A

Linear

23
Q

What are improved with exercise training regarding time to exhaustion?

A

Increased capillarization + increased mitochondrial capacity
(more mitochondrial enzymes lead to a bigger portion of pyruvate being utilized, which decrease the lactate formation) –> Change in substrate utilization: more fat is utilized

24
Q

Give an overview of effect of endurance exercise training on VEmax, VO2max, Qmax, SVmax, heart volume, plasma volume, and submax HR

A

Increase everything but submax HR, which is decreased.

25
Q

Give an overview of effect of endurance exercise training on capillarization, oxidative enzymes, submax blood lactate and submax RER.

A

Increase in capillarization and oxidative enzymes, decrease in submax blood lactate and submax RER

26
Q

Desribe glycolysis/glycogenolysis.

A

Glucose/glycogen –> pyruvate –> 2 ATP + lactate in cytoplasm
During high intensity, short time exercise
Not a lot of ATP

27
Q

Describe oxidative phosphorylation.

A

Electrontransport chain in mitochondria
More ATP
Longer periods of exercise

28
Q

Describe creatine kinase.

A

PhosphoCreatin + ADP –> ATP
Fast conversion, early in exercise
Small amount

29
Q

What is hypoxia?

A

Low ambient O2 levels

30
Q

Per how many metres does the barometric pressure decrease by half?

A

5500 m

31
Q

What are the PO2_alv and PO2_art at sea level, and how low can PO2_art be before the turning point?

A

PO2_alv (sea): 105 mmHg
PO2_artv (sea): 100 mmHg
Critical PO2_art: 60 mmHg

32
Q

At which altitude is the PO2_art app. 60 mmHg?

A

> 3 km

33
Q

What does hypoxia lead to?

A

Low ambient O2 –> reduction in max obtainable arterial O2
Low gradient between alveolar air and pulmonary capillary blood –> equilibrium may not be reached
O2 uptake might become diffusion limited

34
Q

How does the body cope with acute hypoxia?

A
  • Peripheral chemoreceptors sense low PO2 –> signals to CNS –> increased (hyper) ventilation –> increased PO2_alv
  • Submax HR increase
  • SV decrease a bit
  • Submax CO increase
35
Q

What protects the PO2_art at altitudes </= 3 km?

A

Characteristics of the O2-Hb dissociation curve

36
Q

How does the altitude affect the ability to perform?

A

VO2max decrease with altitude
Saturation of O2 also decreses,

37
Q

What are the effects of prolonged hypoxia (acclimatization to high altitude)?

A
  • Increase in red blood cell production => [Hb] increase –> hematocrit value increase
  • VE_alv increase
  • Submax HR decrease
  • DPG increase in red blood cells (glycolysis intermediate) –> reduce Hb saturation –>O2 is easilier delivered to tissue
  • Increased pulmonary diffusion capacity
  • May affect tissue capillarization
  • Increase in oxidative enzymes
38
Q

Why is the ventilation not reduced at prolonged hypoxia because of the higher pH?

A

Normally: VE increase –> PCO2_alv decrease –> PCO2_art decrease –> pH increase –> reduced VE
BUT: the body will decrease pH by secreting less acid in urine –> ventilation is not reduced

39
Q

What makes the hematocrit increase?

A

EPO (erythropoietin) signaling

40
Q

How is EPO expression increased during hypoxia?

A

By HIF1 = hypoxia inducible factor 1, which is a transcription factor

41
Q

Where is EPO secreted from?

A

The kidney

42
Q

Describe how EPO is produced.

A

HIF-1-alpha is degraded when O2 is availble, but not during hypoxia
HIF-1-beta is always present
HIF-1-alpha + HIF-1-beta –> HIF-1 => EPO transcription

43
Q

What is the function of EPO?

A

Prevents apoptosis of red cblood cells (erythrocytes) (is anti-apoptotic)

44
Q

What might EPO signaling in the brain contribute to?

A

BDNF increase. Low BDNF levels has been associated with depression

45
Q

How are HIF-1-alpha regulated?

A

By hydroxylation

46
Q

What is hyperthrophy?

A

Increase in diameter of muscle cell.

47
Q

What are the mechanisms behind hyperthrophy?

A

Resistance exercise induce a net protein synthesis.
Degradation of muscle protein –> net increase in muscle protein

48
Q

What are satellite cells in muscles?

A

“Stem cells” involved in muscle hyperethrophy and reparing muscle damage

49
Q

What activates satellite cells?

A

IGF-1 and myogenin mRNA

50
Q

What is myostatin mRNA?

A

A growth inhibitor

51
Q

What does endurance exercise increase in transcription?

A

Stress responsive genes (very short half-life: 1-2 h), early responding metabolic genes (half life app. 12 h), and mitochondrial enzyme genes (app. 24 h)

52
Q

How can transcription factors be regulated?

A

By de/phosphorylation:
- Localization
-Affinity for DNA
- Transcriptional activation
By proteolytic cleavage:
- Localization

53
Q

What are transcriptional coactivators often recruiting?

A

HAT, which mediates loosening of chromatin structure enabling transcription