Lab Exam 1- Lab 3

Question 1

as exercise intensity increases from mild (25% VO2 max) to moderate (65% VO2 max) to hard (80% VO2 max), what becomes increasingly important

Answer 1

relative contribution of CARBS

Question 2

what % of VO2 max is considered mild intensity

Answer 2

25% VO2 max

Question 3

what % of VO2 max is considered moderate intensity

Answer 3

65% VO2 max

Question 4

what % of VO2 max us considered high intensity

Answer 4

80% VO2 max

Question 5

crossover concept

Answer 5

as exercise intensity increases, there is an increase in the contribution of CARBS as an energy source

Question 6

every RER has a corresponding

Answer 6

caloric equivalent for O2 and the estimated contribution of carbs and fat to energy production

Question 7

given total energy expenditure what can we calculate

Answer 7

the absolute amount of energy production from a given substrate

Question 8

how and where are carbs stored

Answer 8

in the liver and muscle as glycogen

Question 9

how and where are lipids stored

Answer 9

as triglycerides in adipose tissue and intramuscular deposits

Question 10

how do we monitor substrate utilization during exercise in this lab

Answer 10

via indirect calorimetry

Question 11

indirect calorimetry

Answer 11

uses accurate measurements of expired CO2 and O2 to calculate respiratory

Question 12

O2 consumption represents

Answer 12

the total energy expenditure during submaximal, steady-state exercise, and as exercise intensity increases, VO2 and total energy expenditure increase linearly

Question 13

relative vs absolute contributions of fats and carbs at low intensity

Answer 13

relative contribution of fats is higher, but the absolute number of total calories is loweer
absolute amount of oxidation is lower

Question 14

relative vs absolute contributions of fats and carbs at moderate intensity

Answer 14

the relative contribution of fats is lower, but the absolute number of total calories is higher
absolute amount of oxidation is higher

Question 15

RER

Answer 15

respiratory exchange ratio
VCO2/VO2
used to estimate substrate utilization because fats and carbs use and produce different amounts of CO2 and O2

Question 16

three major substrates for energy production

Answer 16

carbs
fats
proteins

Question 17

what are we measuring in this lab

Answer 17

substrate utilization at 3 different intensities either on a cycle OR on the treadmill

Question 18

what happens with an active muscle cell

Answer 18

mitochondria can oxidize glucose at much higher rate than free fatty acids

Question 19

when does an untrained individual reach their crossover point (50% carbs/50% fat)

Answer 19

30% VO2 max

Question 20

when is protein used as a fuel source

Answer 20

under conditions of muscle glycogen depletion (exhaustive exercise or starvation)

Question 21

when VCO2/VO2 is known,

Answer 21

the total energy expenditure (carb+fat) can be calculated

Question 22

when will a trained athlete reach their crossover point

Answer 22

40-50% VO2 max

Question 23

where and how are proteins stored

Answer 23

in muscle as bodily protein

Question 24

where do substrates for energy production come from

Answer 24

foodstuffs but stored in various forms

Question 25

which substrate is not considered a major contributor to energy production during exercise

Answer 25

protein

Question 26

why is it advantageous to have a delay in crossover (carbs into fats) in trained individuals

Answer 26

conservation of limited glycogen stores

Question 27

what is required to calculate RER

Answer 27

must be at steady state
non protein

Question 28

why does RER exceed 1.0 at higher workloads

Answer 28

hyperventilation

Question 29

do CHO yield less or more energy per LO2

Answer 29

CHO = more energy (kcal) per LO2

Question 30

factors that determine fuel selection

Answer 30

intensity
duration
training status
diet

Question 31

what does training status do to oxidative capacity

Answer 31

increases

Question 32

what happens to crossover point with training

Answer 32

crossover shifts right (greater %VO2 max) which increases fat utilization

Question 33

what does training do to mitochondrial density

Answer 33

increases

Question 34

what does training do to capillary density

Answer 34

increases

Question 35

what does training do to FFA transport and oxidation

Answer 35

increases

Question 36

training affects on glycogen use

Answer 36

spares glycogen- use less

Question 37

fat burning zone

Answer 37

the highest oxidation of fats occurs at 50% exercise intensity (% VO2 max)
Absolute amounts (kcal/hr)

Question 38

As exercise duration increases what happens to contribution of Fats/CHOs

Answer 38

there is an increase in FAT utilization and a decrease in CHO utilization

Question 39

acute diet manipulations affects on substrate utilization

Answer 39

consuming CHO before or during ACUTE exercise increases CHO utilization and decreases FAT utilization

Question 40

chronic diet manipulations affects on substrate utilization

Answer 40

consuming a high CHO diet increases CHO utilization during submaximal exercise, whereas consuming a high FAT diet increases FAT utilization

Question 41

why does CHO intake reduce FAT utilization and what are the implications for performance

Answer 41

glucose inhibits lipolysis which decreases the number of fats that are available