Lecture 2

Question 1

Steady State Aerobic Exercise System contributions at different intensities

Answer 1

Question 2

Energy sources at constant intensity submaximal aerobic exercise onset

Answer 2

Question 3

Immediate Energy store for muscular contraction: The CP-ATP system

“stored” ATP in cell used for:

Answer 3

rapid transitions in energy expenditure

Question 4

Immediate Energy store for muscular contraction: The CP-ATP system

Engaged at:

Answer 4

• start of exercise or abrupt changes in effort

Question 5

Immediate Energy store for muscular contraction: The CP-ATP system

Limited store:

Answer 5

6-8 seconds of all out-work

Question 6

Immediate Energy store for muscular contraction: The CP-ATP system

Rapid resynthesis of this “storage” pool of ATP is accomplished via

Answer 6

hydrolysis of creatine phosphate (CP)

Question 7

Immediate Energy store for muscular contraction: The CP-ATP system

Transfer rate is __X that of aerobic pathways

Answer 7

4-8X

Question 8

Energy demand equation

-catalyzed by

Answer 8

CP + ADP → ATP + C

• catalyzed by creatine kinase*
• ATP levels will decrease in active muscle with critical depletion of CP stores*

Question 9

Recovery (rapid) equation

Answer 9

C + ATP → ADP + CP

Question 10

From what is recovery ATP derived?

Answer 10

Catabolism of foodstuffs via glycolysis or aerobic metabolism

Question 11

Testing Capacity of Immediate Energy System

Performance

Answer 11

Power tests:

• stair climbing, jumping
• sprint (40yd sprint for football)
• power tests used for specific performance gains with training (within the same subject) and for training itself

Question 12

Testing Capacity of Immediate Energy System

Assumptions/Design

Answer 12

• All ATP is generated via CP-ATP system at peak power output
• Enough CP/ATP stored to support maximum performance

Question 13

Testing Capacity of Immediate Energy System

Significant limitations

Answer 13

• Test <6 seconds
• link of performance and general CP-ATP capacity hard to assess in field tests
• Performance is skill & motivation dependent

Question 14

Short term system: glycolysis

Duration:

Additional ATP production from:

Answer 14

>6s

Additional ATP production from glycolysis and aerobic mechanisms

Question 15

Short term system: glycolysis

Proportion provided from anaerobic/aerobic sources depends on

Answer 15

intensity and duration of exercise

Question 16

Short-term Energy system tests

Performance for anaerobic power

Answer 16

• Wingate test (cycle ergometer or arm crank)
• Repetitive testing (running, weightlifting)

Question 17

Short term system: glycolysis

Assumptions/design criteria

Answer 17

• Substantial activation of anaerobic systems during maximal exercise up to 3 min
• Must control for task complexity and muscle group specificity

Question 18

Wingate test

Answer 18

30 sec. all out effort with a specific resistance chosen based on body mass (arm crank or cycle ergometer)

Question 19

Wingate test outcome measures

**Peak power output vs average power output

Answer 19

• Peak power output: assumes CP-ATPase capacity is tested
• Average power output: assumes glycolytic capacity tested

Resultant “power scores” compared to age and gender normative values

Question 20

Long-term energy: Aerobic Metabolism

Provides majority of ATP if exercise is:

Answer 20

>2-5mins

Question 21

Long-term energy: Aerobic Metabolism

Oxygen needed to drive ATP production via

Answer 21

• increased pulmonary O2 uptake and
• Delivery to muscle via CV system

Question 22

Rest-to-Exercise Transition in Oxygen Uptake

Answer 22

• The rise in oxygen uptake (VO2) “lags” begin energy expenditure at the start of exercise.
• Oxygen defecit during transitional stage represents energy provided by anaerobic metabolism
• After several mins (3-4) of constant intensity of submax exercise, VO2 reaches steady state
• In submax exercise, majority of energy dervied from aerobic processes
• Steady state, submax exercise = Balance between energy demand (expenditure in kcala) and oxygen uptake
• **THUS → VO2 (O2 uptake) = good index of energy expenditure

Question 23

Recovery from exercise

Answer 23

• At cessation of exercise, VO2 does not immediately return to resting levels
• Excess postexercise oxygen consumption (EPOC) = difference between predicted resting VO2 and actual VO2 measured during recovery
• Rate of recovery to basal levels will depend on the intensity and duration of exercise: higher intensity or longer duration increase EPOC

Question 24

Think of EPOC as:

Answer 24

extra energy necessary to return the body to the pre-exercise state

Question 25

Two components to the exponential fall in VO2

Answer 25

1. Fast (maximal in first 30s) 2. Slow (could take 1-to up to 24 hours) 1. *particularly important after exercise of moderate-heavy intensity*

Question 26

Causes of fast EPOC

Answer 26

1. Resynthesize CP and ATP stores in muscle 2. Replace O2 blood stores in blood, body fluids, and myoglobin

Question 27

Causes of slow EPOC

Answer 27

1. Lactate removal (oxidation and gluconeogenesis) 2. Elevated core temp (increases metabolism) 3. Elevated horomoes (increases metabolism affecting heart, liver, muscle function) 4. O2 demands of heart, respiratory muscles, etc. during recovery

Question 28

Number of calories burned during EPOC

Answer 28

* Interindividual EPOC variaation * Typical exercise (walking, jogging - 30 min @ mod intensity) * EPOC \< 50kcal * Longer (\> 60 min) or higher intensity (\>70% VO2 max) * EPOC from 70-160kcal *ppl on moderate exercise programs looking to lose weight should concentrate on increasing frequency or duration of the exercise itself (rather than counting on EPOC) to meanfully increase caloric expenditure in pursuit of their goal*

Question 29

*Maximal oxygen comsumption (VO2 max)* Physiologic definition

Answer 29

Maximal capacity to transport and utilize O2

Question 30

*Maximal oxygen comsumption (VO2 max)* Operational definition

Answer 30

VO2 at which O2 uptake no longer increases with an increase in workload

Question 31

*Maximal oxygen comsumption (VO2 max)* Peak aerobic power or peak oxygen uptake (VO2 peak)

Answer 31

* Term used when its not clear that exercise elicited “true” physiologic VO2 max * VO2 plateau in VO2 not demonstrated (common in exercise testing)

Question 32

VO2max is a fundamental measurement in:

Answer 32

in exercise physiology *an important component of endurance performance*

Question 33

**_VO2 max reflects (2 things)_**

Answer 33

1. capacity for aerobic energy transfer 2. **_Function and integration of physiological systems involving uptake, delivery, and utilization of oxygen_**

Question 34

VO2 max diagram (relative vs. absolute)

Answer 34

Question 35

Oxygen transport system

Answer 35

1. pulmonary ventilation 2. Transfers O2 to blood 3. Cardiac function 4. Blood flow to active muscles (organs) 5. Transfer O2 to muscle 6. Metabolic function of muscle

Question 36

Absolute workload expressed as

Answer 36

* ml/min/kg * l/min * Watts, mph, kgm-min,

Question 37

Relative workload expressed as

Answer 37

* Relative (%) to a standard (usually that person's maximum HR or maximum VO2)

Question 38

VO2 reserve

Answer 38

VO2 max - resting VO2

Question 39

Expressions of intensity as relative workloads allows for comparisons of exercise responses between different persons because:

Answer 39

* individuals should be working at the _same relative physiologic stress_ even if the absolute workloads are different

Question 40

At the SAME absolute workload, subject A is working at a lower % of Maximum Capacity compared to subject B

Answer 40

Question 41

At the same relative workload, Subject A is working at a higher absolute workload than subject B

Answer 41