Energy expenditure

In direct calorimetry how much energy from metabolism is lost as heat?

60%

Direct calorimetry ____ energy expended by ____ heat produced

estimates, measuring

Indirect calorimetry ____ energy ____ by measuring ___ ___ and ___ ___

Estimates, expended, O2 consumed, CO2 produced

Respiratory exchange ratio (RER)

RER= VCO2/VO2

CHO (carbohydrate) oxidation

C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O + 38 ATP 6 CO2/6 O2 RER = 1.0

How much RER does CHO (carbohydrate) oxidation produce?

RER= 1.0

Palmitic acid (fat) oxidation

C16H32O2 + 23 O2 —→ 16 CO2 + 16 H2O +129 ATP 16 CO2/23 O2 RER=0.7

How much RER does palmitic acid (fat) oxidation produce?

RER= 0.7

What is RER used to estimate?

%kcal derived from fat vs. carbohydrate

Primary substrate at rest is __

Fat

Increase reliance on ____ as exercise intensity ___

Carbohydrate, increases

Why does the shift occur to carbohydrate?

1. Fat metabolism is slow

2. Lactic acid inhibits lipolysis

During steady state exercise when is VO2 reached?

1-2 min

There is a ___ increase in ___ as power increases

linear, VO2

VO2 at any submax workload is ___

Similar

Does training increase or decrease VO2 max?

Increase

Does training increase or decrease CO max?

Increase

Does training increase or decrease a-v O2 diff max?

Increase

What provides some ATP in excess post exercise O2 consumption?

Anaerobic metabolism

O2 supplied = ?

O2 required

VO2 stays ___ to restore homeostasis

elevated

What is the O2 deficit phase due to?

Due to time lag in CV adjustments

What is steady state due to?

Due to feedback from group III and group IV nerves

What is excess O2 used to do?

1. Replenish ATP/PCr stores

2. Convert lactic acid to glycogen

3. Reoxygenate hemoglobin and clear CO2