Chapter 3

Question 1

protein oxidation

Answer 1

-amino acids converted into glucose or various intermediates of oxidative metabolism
-protein burned in lab yields 5.65 kcal/g, but in body only 4.1 kcal/g [in body N, must be removed in urea cycle, which uses energy. Urea excreted in urine]
-to measure protein use for energy in body, we must know rate of urea formation
~requires urine collection over 12-24 hours
~since little protein used for energy, we usually ignore protein use in determining energy expenditure

Question 2

Balancing Act For Fuels

Answer 2

HEAVIEST TO LIGHTEST
-ATP, PCr, CHO, Fat

MOST TO LEAST ENERGY SUPPLIED PER GRAM
-Fat, CHO, PCr, ATP

QUICKEST ATP TURNOVER RATE
-ATP, PCr, CHO, Fat

-balancing act between most efficient and lightest to store vs. what gives us ATP quickest
-review what fuel used what situations and how that applies to type of training you do.
EXAMPLE: sprinter vs. marathoner

Question 3

Interaction Between Aerobic and Anaerobic ATP Production

Answer 3

-Energy for exercise comes from an interaction between aerobic and anaerobic pathways

effect of duration and intensity

• short-term, high-intensity activities
• long-term, low to moderate-intensity exercise

Question 4

Resting Energy Requirements

Answer 4

AEROBIC
O2 CONSUMPTION (VO2)
-3.5 ml/kg/min

RESTING ENERGY EXPENDITURE
-1 kcal/min

relative measure of VO2: ml/kg/min
absolute measure of VO2: ml/min

Question 5

Rest to Exercise Transition

Answer 5

ANAEROBIC AND AEROBIC

• In transition, VO2 increases rapidly and reaches steady-state in 1-5 min.
• Until VO2 reaches steady state, must use anaerobic systems
• ATP-PCr, then anaerobic glycol’s, then aerobic
• Once steady-state reached, mainly aerobic

O2 DEFICIT

• during time aerobic systems are ramping up, the difference between the steady-state VO2 and actual VO2 is O2 deficit
• exercise intensity
• training (aerobic training)
• lower O2 deficit, your body is used to it.

Question 6

Recovery from Exercise

Answer 6

• MR remains elevated several min. post-ex
• Magnitude and duration of recovery period influenced by exercise intensity
• The higher the intensity of exercise
• EPOC (O2 debt)- VO2 above that needed at rest during initial minutes of recovery
• Extra O2 consumption after exercise to bring physiological variables back to resting level

CLASSICAL THEORY-reapy O2 deficit

1. FAST (2-3 MIN)- rebuild ATP & PCr stores in blood and muscle
2. SLOW (> 30 MIN)- remove lactate

Question 7

Research EPOC Reasearch

Answer 7

OTHER “NON-ANAEROBIC” FACTORS ALSO INVOLVED

1. Elevated Tb
2. Elevated Hormone Levels
3. Elevated HR
4. Elevated Breathing Rate

INTENSITY
TRAINING [less EPOC]

Question 8

Prolonged Exercise

Answer 8

• Aerobic
• Usually steady-state VO2 can be maintained during submax ex. of moderate duration

EXCEPTIONS

1. hot/humid environment - VO2 “drifts” upward
2. high relative work rate (>75% VO2 max)
   - due to effects of increase Tb & E/NE

Question 9

Incremental Exercise or GXTs

Answer 9

• TESTS USED TO DETERMINE
  1. CV fitness (VO2 max)
  2. Possible heart disease
• Work rate increases every few (1-5) min. until subject can’t maintain desired power output
• Can be done on any type of ergometer

Question 10

Aerobic Capacity, Maximal O2 Uptake or VO2 max

Answer 10

-POINT AT WHICH VO2 FILS TO INCREASE WITH DECREASE EXERCISE INTENSITY.

• Factors influencing
  1. Cardiorespiratory ability to deliver O2 to muscle
  2. Muscle’s ability to uptake and use O2
• Determined by genetics and aerobic training (equal influence on VO2 max)
• 15-20 % common w/aerobic training
• Best measure of cardiorespiratory endurance and aerobic fitness
• % VO2max-most commonly used measure of relative exercise intensity

Question 11

Respiratory Exchange Ratio

Answer 11

• Other methods, such as direct calorimetry, exist to estimate energy expenditure, but indirect calorimetry by RER is most common method
• Ratio of CO2 expired to O2 inspired at lungs
• Indicated aerobic CHO vs. fat use (non-pro)
• assumes O2 and CO2 respired @ lungs = O2 and CO2 used/released by aerobic metabolism
• only valid when used at rest or during steady-state ex.
• RANGE:
• RESTING AVG: