Lab 4b: Lactate Clearance Response to Supramaximal Testing

What is the purpose of the lab on lactate clearance?

To evaluate the effects of recovery method on systemic blood lactate clearance rates after intense anaerobic exercise.

What are the two types of recovery methods compared in the lab?

Active recovery (light-moderate exercise) vs. passive recovery (complete rest).

What is lactate a by-product of?

Anaerobic glycolysis.

What happens to pyruvic acid when there is insufficient oxygen?

It is fermented into lactic acid.

What percentage of lactate is oxidized after exercise?

70% is oxidized to pyruvate to enter the Krebs cycle.

How much lactate is converted to glucose?

20% is converted to glucose through gluconeogenesis in muscle or liver.

What is the typical blood lactate concentration at rest?

0.5-2 mmol/L.

What is the maximum blood lactate level?

30 mmol/L.

How long does it take to clear 50% of lactate after maximal anaerobic exercise?

~25 minutes of passive recovery.

What is the effect of active recovery on lactate clearance?

Active recovery demonstrates a much faster rate by circulating lactate to the body.

What is the lactate threshold for untrained individuals?

50-60%.

What is the lactate threshold for aerobically trained individuals?

70-80%.

How does aerobic training status affect lactate clearance?

Aerobically trained individuals have slower clearance and require active recovery at lower intensity.

What is the effect of anaerobic training status on lactate accumulation?

Anaerobically trained individuals may generate greater peak levels of blood lactate.

What happens to blood pressure post-exercise?

Post-exercise hypotension occurs due to dilation of blood vessels.

Why is active recovery encouraged after exercise?

To prevent a large drop in blood pressure by maintaining muscle pump activity and venous return.

What is the procedure for measuring blood lactate?

Finger stick to collect blood sample, using a test strip in an analyzer.

What should be done with the first blood droplet during lactate measurement?

Wipe away the first droplet with gauze to avoid contamination.

What is the timeline for blood lactate assessment after exercise?

Immediately post, 5 minutes post, 15 minutes post, and 25 minutes post exercise.

What is the resistance and RPM for active recovery during the lab activity?

Pedaling at 50 RPM with a resistance of 1-2 kp for 25 minutes.