Lactate

Question 1

lactate production-basics

Answer 1

pyruvate is converted to lactate and hydrogen by lactate dehydrogenase

Question 2

increase in blood lactate …

Answer 2

increases h ions and therefore decrease ph (more acidic)

Question 3

what determines lactate concentration

Answer 3

balance between rate of lactate production and rate of lactate clearance

Question 4

where does most lactate oxidation occur

Answer 4

working ,muscles (in adjacent fibres) 55-70%
20-25% liver and kidneys
10% cardiac muscles

Question 5

lactate shuttling

Answer 5

lactate is shuttled from fast twitch fibres to type 1 fibres in same muscle to oxidise

Question 6

how to use lactate as fuel

Answer 6

moving it to other aerobic muscles converting it back to pyruvate
or move to liver for gluconeogenesis

Question 7

why measure blood lactate

Answer 7

predict endurance performance
indicate sub max fitness
monitor training intensity

Question 8

what happens when blood lactate exceeds a certain concentrate

Answer 8

exercise duration becomes finite

Question 9

lactate threshold

Answer 9

0.2mmol/L
0.5
first sig elevation (>2mmol

Question 10

lactate turnpoint

Answer 10

second lactate increase of at least 05mmol/L from previous value

Question 11

Dmod

Answer 11

maximal distance from BLa curve to line formed by point before first raise and the value at cessation

Question 12

maximum lactate steady state

Answer 12

highest blood lactate conc that can be maintained over time without continual accumulation

Question 13

what happens at intensities higher than lactate turn point

Answer 13

anaerobic processes lead to gradual build up of h ions and other metabolic products in muscle leading to fatigue

Question 14

training zones

Answer 14

low <2mmol 70% vo2 max
moderate 2-8mmol 70-90% vo2 max
servere >2-8mmol >90%vo2max