Lab 3 + 4 prep

Question 1

% muscle mass to total mass

Answer 1

40% avg

- large organ

Question 2

skeletal muscle contribution to resting metabolic rate

- change with maximal exercise

Answer 2

20% resting metabolic rate

• can increase 100-fold from rest to exercise
• very fast at turning on

Question 3

ATP storage?

Answer 3

no

- when made, utilized immediately

Question 4

purpose of metabolic pathways

Answer 4

produce electron donors

- NADH and FADH2

Question 5

aerobic metabolism

- production of ATP

Answer 5

oxidative phosphorylation

- fat and carbs

Question 6

anaerobic metabolism

- production of atp

Answer 6

glycolysis and phosphocreatine

• substrate phosphorylation
• carb only

Question 7

when is anaerobic energy required

Answer 7

transitions
- from one power output to another
sprinting
- 90-100% VO2 max
reduced O2 availability 
- swimming and altitude

Question 8

avg VO2 max

Answer 8

3.5L/min

Question 9

improving anaerobic metabolism

Answer 9

anaerobic glycolysis 
- can increase with training
PCr
- very small increase
- 10-20% by increasing muscle mitochondria (more muscle)
- artificial increase with supplements

Question 10

humans energy efficiency

Answer 10

23-27%

- designed to keep ourselves warm

Question 11

direct calorimetry

Answer 11

heat production

• measure energy burned by heat produced
• food stuff + O2 –> atp + heat + CO2

Question 12

indirect calorimetry

Answer 12

CO2 production - spirometry

• measures O2 used
• food stuff + O2 –> atp + heat + CO2

Question 13

2 types of spirometry

Answer 13

1) closed - chamber - flow through of air

2) open, measures inspired or expired **

Question 14

how to measure metabolic rate

Answer 14

3 inputs

• in/expired CO2
• in/expired O2
• work output

Question 15

fraction inspired air

• O2
• CO2
• N2

Answer 15

O2 - 20.93%
CO2 - 0%
N2 - 79.04%

Question 16

fraction expired air

• O2
• CO2

Answer 16

O2 - 16.5%

CO2 - 2.5%

Question 17

respiratory exchange rate (RER)

Answer 17

Glucose
- 6O2 --> 6CO2
- RER = 1
Fat
- 23O2 --> 16CO2
- RER = 0.7

Question 18

Resting relative VO2 (to mass)

Answer 18

3.5-4.0 mL/kg/min

Question 19

reason for RER > 1

Answer 19

1) acid produce high intensity
- buffering produces CO2

2) hyperventilation
- body exhales mores store

Question 20

RER caloric equivalent (Kcal/L O2)

- carbs and fat

Answer 20

carbs
- 5.047 kcal/L

fat
-4.686 kcal/L

Question 21

RER at:

• low intensity
• mid intensity

Answer 21

low intensity

- RER 0.9

Question 22

energy expenditure calculation

Answer 22

Kcal = VO2 x RER caloric equivalent x time

Question 23

relative contribution of fat and carb to energy expenditure

Answer 23

% kcal from fat = [(1-RER)/(1-0.7)] x 100

% kcal from carb = 100 - (%kcal from fat)

Question 24

energy from fat

Answer 24

food - 9.3 kcal/g
body - 7.7 kcal/g

• body is lower because of connective tissue

Question 25

energy from carbs

Answer 25

4.1 kcal/g

Question 26

measurement of efficiency

Answer 26

(power x time) / (Ve x KJoules) | - avg 25%

Question 27

how metabolic cart calibration works

Answer 27

- turns volts into meaningful value for gas fractions - limitations of VO2 measurement relates to how accurate the gas calibrations are - also calibrate flow-volume (3L syringe)

Question 28

valve used to measure expired air only

Answer 28

rudolf valve

Question 29

how to calibrate Monark bike power output

Answer 29

LODE bike - 1 point calibration - at one power output - multiple better

Question 30

RER accuracy

Answer 30

not ideal measure - O2 exhaled not just from muscle - other tissues as well - 85% muscle during exercise (blood flow) so a good indicator

Question 31

assumptions for RER use

Answer 31

1. subject in steady state 2. other fuels minimal contribution (protein, acetate) 3. hyperventilation a problem at max exercise 4. no other "non-fuel" O2 use - de novo synthesis of fat in adipose tissue - CO2 production acidic muscle (bicarbonate buffering)

Question 32

indicators VO2 max is reached

Answer 32

1. 95% predicted max HR 2. RER > 1.1 3. VO2 plateau *** 4. Ve plateau 5. blood lactate >10mM

Question 33

predicting VO2

Answer 33

submax VO2 test - go to 85% max HR - record 2 HR values >110bpm - estimate VO2 max at max HR - estimated VO2 for specific power ouputs

Question 34

benefits and limitations to VO2 submax test

Answer 34

benefits - cost - safer limitations - estimates all measures - assumes constant efficiency between individuals - only 2 HR values - not very accurate for athletes or active people

Question 35

VO2 max test name

Answer 35

Astrand "continuous test"