Substrate Utilization

Question 1

• Oxygen uptake: V̇O2
  A rate (…)
• Carbon dioxide production: V̇CO2
  A rate (…)
• Respiratory exchange ratio (RER)
  …. / ….
  RER = … / …

What influences substrate oxidation?
1) Exercise …
2) Exercise …
3) …
4) …
5) T…

Answer 1

• Oxygen uptake: V̇O2
  A rate (L/min or mL/min)
• Carbon dioxide production: V̇CO2
  A rate (L/min or mL/min)
• Respiratory exchange ratio (RER)
  Carbon dioxide produced / Oxygen consumed
  RER = V̇CO2 / V̇O2

What influences substrate oxidation?
1) Exercise intensity
2) Exercise duration
3) Substrate availability
4) Sex
5) Training status

Question 2

RER = V̇CO2 / V̇O2
* If RER = 1.0, … is the fuel
* If RER = 0.71, … is the fuel
* If 1.0 > RER > 0.71, the fuel is …

Glucose (C6H12O6 + 6 O2 → 6 CO 2 + 6 H2O)
* RER = …/… = …
* … kcal / L O2

Trioleate (C57H104O6 + 80 O2 → 57 CO2 + 52 H2O)
* RER = 57/80 = …
* … kcal / L O2

Answer 2

RER = V̇CO2 / V̇O2
* If RER = 1.0, carbohydrate is the fuel
* If RER = 0.71, lipid is the fuel
* If 1.0 > RER > 0.71, the fuel is a mix of carbohydrate and lipid

Glucose (C6H12O6 + 6 O2 → 6 CO 2 + 6 H2O)
* RER = 6/6 = 1.0
* 5.05 kcal / L O2

Trioleate (C57H104O6 + 80 O2 → 57 CO2 + 52 H2O)
* RER = 57/80 = 0.71
* 4.69 kcal / L O2