Substrate Utilization Lab Practical:

Question 1

Substrate Utilization: Practical

Answer 1

Fasted vs. Carbohydrate-Fed Conditions:

In the fasted condition:
Lower RER values, typically around 0.7-0.8
Higher fat oxidation rates
Lower carbohydrate oxidation rates

In the carbohydrate-fed condition:
Higher RER values, typically around 0.85-0.95
Lower fat oxidation rates
Higher carbohydrate oxidation rates

general consensus would typically be that pre-exercise carbohydrate ingestion:
Increases carbohydrate oxidation during subsequent exercise
Decreases fat oxidation during subsequent exercise
This effect is more pronounced at lower exercise intensities and becomes less significant as exercise intensity increases