Week 2

Question 1

What are the main fuel sources?

Answer 1

Carbs
Fats
Proteins
Phosphocreatine
ATP

Question 2

Factors determining energy pathways utilisation? Main 2?

Answer 2

Main two:
Exercise intensity
Exercise duration

Others:
Training status
Diet
Sex
Environmental conditions

Question 3

Metabolic response to intense exercise?

Answer 3

Initial energy comes from substrate level phosphorylation.

Lactate builds up quickly as glycogen is rapidly used due to anaerobic glycolysis

PCr depletes (usually after 30s) and lactate builds up = fatigue

To recover lactate must be cleared and PCr must be replenished

Once depleted OP is the highest contributor but it is slower therefore happens later

Question 4

Metabolic response to endurance exercise?

Answer 4

ATP is primarily by Carb and Fat oxidation, with carb being the primary fuel.

Carbohydrates are more dominant at higher intensities whereas fats are more at lower intensities

Glycogen depletion is a key factor in fatigue during endurance activity

Question 4

How quick are stores recovered?

Answer 4

PCr stores are replenished within minutes.

Glycogen stores require dietary carbohydrate and take longer to restore

Question 5

Where are fuel sources stored?

Answer 5

Carbs - Muscle/Liver glycogen

Fats - Triglycerides in adipose tissue

Proteins - stored as muscle proteins and broken down into amino acids