Lactate

Question 1

What is lactate associated with during heavy exercise?

Answer 1

Acidic environment (hypoxic).
Reflected by an elevated glycogen utilisation and depleted level.

Question 2

Why do we measure blood lactate over lactic acid?

Answer 2

Lactic acid is produced and H+ immediately dissociates to form lactate.

Question 3

Why does lactate accumulate? State the fibres involved.

Answer 3

Clearance in type I fibres < Production in type II fibres

Question 4

Why is blood lactate produced more in type II fibres?

Answer 4

Type II fibres contain more glycolytic enzymes which function anaerobically.

Question 5

Define lactate threshold 1.

Answer 5

First significant elevation of lactate level (approximately 2mmol/L above resting value).

Has a strong correlation in determining race pace.

Question 6

Define lactate turnpoint.

Answer 6

Second increase of at least 0.5mmol/L from the previous value. Above this, lactate increases exponentially.

Lactate turnpoint is good at determining 10-40km time trial pace.

Question 7

What is maximum lactate steady state.

Answer 7

Lactate threshold 2.
Highest blood lactate concentration that can be maintained over time without continual blood lactate accumulation.

Question 8

What happens to blood lactate above MLSS?

Answer 8

Despite a decrease in exercise intensity lactate will continue to be produced and rise.
Anaerobic processes = H+ = fatigue.

Question 9

What effect does endurance training have on lactate thresholds?

Answer 9

Shift to the right.