L1.3 Exercise Metabolism

Question 1

What are the ATP dependent processes?

Answer 1

1) Cross-Bridge Cycle (Myosin ATPase)
2) Sacrolemmal excitability (Na+/K+ ATPase)

• 1+2 = 40%
  3) Ca2+ pumping into SR (SERCA-Ca2+ ATPase)
• 60%

Interference from fatigue due to ↓ATP

Question 2

What are wet muscles?

Answer 2

Water goes into muscles during exercise

Shows diluted [ATP] → DRY muscle [ATP] ~ 4x higher

Question 3

What are the ATP generation processes?

Answer 3

1) Substrate level phosphorylation (20%)

A) Using high energy phosphogens (ATP/PCr)
B) Anaerobic glycolysis

2) Oxidative phosphorylation (Mitochondrial coupling) - Aerobic (80%)

Oxidative metabolism of CHO & fats (& a little protein in extreme conditions

Question 4

What is the power and capacity of metabolism?

And what is the relationship between the 2?

Answer 4

Power = Rate of ATP generation
Capacity = Total amount of ATP that can be generated

INVERSE relationship between power and capacity of energy systems (CHO&fats…)

• *Power**: PCr = Glycolysis > CHO > FFA
• *Capacity**: FFA (almost infinite stores as adipose) > CHO > Glycolysis = PCr

Question 5

What is the relationship between fuels used in high intensity and high duration exercise?

Answer 5

↑intensity fuels: ↑muscle glycogen, ↓fat oxidation
↑duration: ↓muscle glycogen, ↑fat oxidation