1. basics and background

Question 1

Total daily energy expenditure (TDEE)

- 3 groups

Answer 1

1. resting energy expenditure (REE)
   - 60-75%
   - basal metabolic rate / resting metabolic rate
2. thermic effect of food (TEF)
   - 5-10%
   - possibly reduced in obesity (controversial)
3. Physical activity
   ~ 15-30%
   - highly variable

Question 2

difference between basic and resting metabolic rate

Answer 2

BMR
- strict controlled measurement conditions **

RMR
- ~10% greater than BMR

Question 3

what stimulates the thermic effect of food (TEF)

Answer 3

protein and caffeine

Question 4

factors that affect REE (resting energy expenditure)

Answer 4

genetics 
age
- young > old
sex
- men > women (muscle mass mostly)
body size
- height, body surface area
body composition 
- skeletal muscle biggest contribution (40% REE)
environmental temp
- cold, keep body warm
diet and exercise

Question 5

measuring total energy expenditure

Answer 5

measure heat production

direct calorimetry
- persons heat production in sealed chamber

indirect calorimetry

• measure changes in o2 consumption and/or co2
• open circuit spirometry
• “metabolic cart”
• flow meters, gas analyzers

Question 6

problems with indirect calorimetry

Answer 6

hyperventilation
- more co2 released
airtight?
mask comfort?

Question 7

RER

- what can we determine from this

Answer 7

respiratory exchange rate

• VCO2/VO2
• determines the substrates being oxidized

Question 8

VO2 use to calculate energy expenditure

Answer 8

thermal equivalent
~5 kcal per L O2

5 kcal X VO2 (L/min) X time

*nearly the same whether burning fat or oxygen

Question 9

CO2 production (VCO2) assumptions when calculating energy expenditure

Answer 9

assumptions

1. source of co2 production is mitochondrial
2. steady state conditions are present
   - otherwise co2 not completely from fat or carb oxidation

Question 10

what are non-steady state conditions

- co2 production that results

Answer 10

hyperventilation
- increases Vco2 production
recovery from intense exercise
- decrease Vco2

Question 11

RER carb vs fat

Answer 11

pure carb = 1

pure fat = 0.7

Question 12

what influences fuel utilization

Answer 12

at rest

• fat use
• low energy expenditure
• no need to quickly replace ATP
• enough time for lipolysis/beta oxidation
• not fat exclusively (some cell/tissues need glucose)
• 85% fat / 15% carb

Question 13

what is VO2 max

Answer 13

• maximum oxygen consumption and aerobic capacity
• standardized progressive test
• VO2 plateau
• general indicator of aerobic fitness
• L/min or ml/kg/min

Question 14

VO2 max typical numbers

• minimum
• average 50th percentile
• superior 90th percentile
• well trained
• highest elite

Answer 14

(men / women - ml/kg/min)

minimum - 35 / 32.5
average - 40-45 / 35-40
superior - 54+ / 47+
well trained - 60+ / 50+
highest elite - 90+ / 80+

Question 15

oxygen supply vs oxygen demand

Answer 15

supply
- transport of O2 from lungs to mitochondria

demand
- rate at which mitochondria can reduce O2 in oxidative phosphorylation

Question 16

major “limiter” to endurance performance

Answer 16

oxygen supply and delivery

Question 17

arterial oxygen saturation

• %
• is it limiting

Answer 17

how much oxygen each red blood cell is carrying

• > 95%
• not usually limiting

Question 18

high altitude training

Answer 18

body adapts to relative lack of o2
- increase mass of RBCs and hemoglobin
problem -> lower performance during
- live high train low
- tent, room, mask

Question 19

cardiac output measurement

- main limiting factor

Answer 19

stroke volume X heart rate

• O2 supply and delivery
• 70-85% of limitation
• improved with endurance training

main limiting factor

• stroke volume
• HR is similar in trained/untrained

Question 20

O2 extraction

• A-V diff
• limiting?

Answer 20

A-V difference

• 200 to 20 mL O2/ L in blood
• little change with training
• not likely limiting

Question 21

ways to increase o2 carrying capacity

- illegal

Answer 21

erythropoietin (EPO)
increase red blood cells
- can increase VO2 max by 10%

Question 22

peripheral limitations to VO2 max

Answer 22

McArdles disease

• carbs
• muscle phosphorylase deficiency, breakdown glycogen to glucose in muscle

CPTI (carnitine palmitoyl transferase 1) deficiency

• fats
• fatty acid oxidation disorder

mitochondria?

• weak relationship b/w mitochondrial enzymes
• usually not a limitation
• can incr mitochondria 2-fold w training, but get 20-40% increase VO2 max (poor association)

Question 23

whats the advantage of mitochondrial content increasing so much with training (because it doesnt increase VO2 max)

• result of better matching
• meaning in practical term

Answer 23

better matching ATP provision and demand, especially at onset of exercise

• better balance
• decrease ATP, increase ADP, AMP and Pi
• more reliance on fat as fuel