Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

KIN 335 > Lactate - friend or foe > Flashcards

Lactate - friend or foe Flashcards

1
Q

What role does lactic acid play in muscle fatigue?

traditional views

A

Traditionally viewed as a cause of muscle fatigue and exercise performance limitation.

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

How is lactic acid traditionally classified in metabolism?

A

Considered a waste product of anaerobic metabolism.

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

What effects is lactic acid believed to have during intense exercise?

A

Causes “burn,” metabolic acidosis, decreased muscle contractility, and exercise cessation.

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

What was lactic acidosis believed to impair in muscles?

A

Muscle contractility leading to fatigue and exhaustion.

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

What was lactic acid believed to cause in muscles?

A

Uncomfortable feelings and delayed-onset muscle soreness.

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

<p>What is the likely source of proton (H+) release in glycolysis?</p>

A

Non-mitochondrial hydrolysis of adenosine triphosphate (ATP).

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

<p>T/F lactic acid is produced in muscle</p>

A

<p>False</p>

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

What triggers the conversion of pyruvate to lactate during exercise?

A

<p>Increasing concentrations of pyruvate due to the mitochondria being unable to oxidize all the pyruvate<br></br></p>

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

Which enzyme converts pyruvate to lactate?

A

Lactate dehydrogenase.

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

What do Robergs et al argue is the source of H+?

A

Non-mitochondrial ATP turnover is the source of H+.

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

What do Lindinger et al propose about strong acid anions during glycolysis?

A

They necessitate an increase in net positive charge to maintain electroneutrality.

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

How is the positive charge primarily provided during increased glycolytic activity?

A

By the dissociation of water.

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

What are some beneficial effects of acidosis?

A

Greater oxygen release, ventilatory stimulation, enhanced blood flow, increased cardiovascular drive.

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

What misconception is related to lactate and muscular fatigue?

A

Acidosis is a primary cause of muscular fatigue and exercise cessation.

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

What have recent studies shown about acidosis and muscle contraction?

A

Limited effects on skeletal muscle contraction from induced acidosis.

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

What is lactate’s role in metabolism?

A

Lactate is a fuel and signaling molecule, not just a waste product.

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

What facilitates lactate transport in cells?

A

Monocarboxylate transport proteins (MCTs).

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

Lactate can be shuttled out of the cell via what?

A

An MCT, possibly with extracellular H+ transport.

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

What effect do elevated blood lactate levels have on energy substrate utilization?

A

They downregulate the use of glucose and free fatty acids as energy substrates.

20
Q

What happens to blood lactate levels at the start of exercise?

A

Blood lactate levels increase slightly.

21
Q

What triggers glycolysis during exercise?

A

An increase in ATP demand by working muscles.

22
Q

Why is there an initial rise in blood lactate during exercise?

A

Inadequate heart rate and capillary dilatation delay oxygen delivery.

23
Q

What factors contribute to increased blood lactate levels?

A

<ul><li><p>Oxygen delivery</p></li><li><p>mitochondrial capacity</p></li><li><p>lactate clearance/utilization by body cells.</p></li></ul>

24
Q

What is the first difficulty in using lactate threshold as a training aid?

A

Confusion in terminology regarding lactate threshold and related terms.

25
Q

List terms often used interchangeably with “lactate threshold.”

A

<ul><li><p>Anaerobic threshold</p></li><li><p>aerobic threshold</p></li><li><p>lactate turn point</p></li><li><p>OBLA</p></li><li><p>MLSS</p></li></ul>

26
Q

What is the “onset of blood lactate accumulation” (OBLA)?

A

Point where blood lactate begins to increase above resting values during exercise.

27
Q

What does “maximal lactate steady state” (MLSS) refer to?

A

Maximal exercise intensity where continuous blood lactate increase is unavoidable.

28
Q

What is a potential limiting factor in lactate threshold testing and training?

A

Accuracy of measurement.

29
Q

What type of exercise increases lactate threshold in sedentary subjects?

A

Any training stimulus, including very light exercise.

30
Q

What is necessary to increase lactate threshold in well-conditioned athletes?

A

Very intense exercise.

31
Q

How trainable is VO2max according to the meta-analysis?

A

VO2max is minimally trainable.

32
Q

What is as effective as lab-measured blood lactate levels for determining training zones in runners?

A

Rate of perceived exertion

33
Q

What is critical velocity closely correlated with?

A

Power and velocity at MLSS and OBLA.

34
Q

What training plans have cyclists and runners transitioned to?

A

Plans based on critical pace or functional threshold power.

35
Q

What does “critical pace” or “critical power” describe?

A

Maximal workload over a given time or distance.

36
Q

What role does the lactate dehydrogenase reaction play in glycolysis?

A

It maintains cytosolic redox potential and buffers against acidosis.

37
Q

<p>How does the lactate dehydrogenase reaction help buffer against acidosis?</p>

A

It consumes a proton, effectively buffering against acidosis.

38
Q

Lactate transport into mitochondria serves what purpose?

A

To be oxidized.

39
Q

What is coupled with lactate transport into peroxisomes?

A

Reoxidation of NADH, required for B-oxidation.

40
Q

What is lactate uptake dependent on?

A

Lactate uptake is dependent on concentration gradients.

41
Q

<p>Which 2 factors make lactate a preferential energy source in some situations?</p>

A

<ul><li><p>uptake is dependent on concentration gradients and is not limited by transport</p></li><li><p>lactate to pyruvate oxidation is fast and therefore not limiting</p></li></ul>

42
Q

What did Zuniga et al [17] demonstrate about analyzing blood lactate curves?

A

They demonstrated that testing protocols affect OBLA and MLSS estimates more than analysis methods.

43
Q

Glycogen status affects what aspect of lactate testing?

A

Blood lactate curve interpretation.

44
Q

The absolute value of blood lactate at MLSS predicts performance on endurance tasks.

A

False, it does not predict performance on endurance tasks.

45
Q

What strongly predicts performance at MLSS?

A

The workload at MLSS.

46
Q

Is workload at MLSS correlated with absolute blood lactate levels?

A

No, it is not correlated.

47
Q

<p>what is the main advantage a profession has over an amateur even if they have similar VO2max?</p>

A

<p>the ability to maintain high workloads without high lactate concentrations in their blood</p>

KIN 335 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions