Shared Flashcard Set


KiN 360-Leture 6 and 7
Glycogen, O2 Defecit and Dept
Undergraduate 2

Additional Physiology Flashcards




Crossover concept 
Effect of exercise intensity on fuel selection.
Lactate as a fuel source During exercise

can be used as a fuel sorce in the same skeletal muscle cells that produce it- Interacellar Lactate shuttle. Converted to acetyl-CoA and enters Krebs cycle. Can ne converted to glucose in the liver-Gluconeogenesis.

Cori Cycle- can be transported to another tissue and utilized -Lactate shuttle- Lactate produced in one tissue and transported to another tissue-Heart, other skeletal muscles, Kidneys.

Can produces by FOG fibers and used by the SO fibers in the same muscle.






Removal of Lactic Acid following exercise

Classical theory -Majority of lactic acid converted to glucose in liver
Recent evidence
70% of lactic acid is oxidized
 Used as a substrate by heart and skeletal muscle
20% converted to glucose
10% converted to amino acids
Lactic acid is removed more rapidly with light exercise in recovery
Optimal intensity is ~ 30–40% VO2 max 


Biochemical Adaptations to Power and Sprint Training


The main adaptations to short duration high intensity training lasting less than 5 to 10 sec. are:
Increased muscular ATP and CP stores (25% and    40 %, respectively) Increased activity of ATPase, MK, and CPK (30%, 20%, and 36 % respectively)
Main adaptations to short duration high intensity train­ing lasting up to 40 to 60 sec. are:
Increased muscular glycogen levels.
Increased activity of key glycolytic enzymes (up to 83% in PFK activity).


Biochemical Adaptations to Endurance Training


main adaptations to endurance training are:
Increased myoglobin content (up to 26%).
Increased number and size of mitochondria (up to 120% and 40%, respectively)
Increased activity and concentration of the enzymes in TCA and ETC (up to 40%)
Increased glycogen storage (up to 2.5 times)

Increased capacity to utilize fatty acids

Steady state exercise
Energy is mostly supplied by the hydrolysis of ATP,CP< and anaerobic glycolysis-Some accumulation of HLA. Small contribution of enegy by the aerobic metabolic sysytem thought the utilization of stored oxygen.
Oxygen deficit

the discrepancy between oxygen demand and supply during an exercise or the oxygen equivalent of energy supplied by the anaerobic metabolic system plus the extra amount of oxygen extracted from the body stores

Oxygen equivalent of energy supplied by the  ATP/CP System

Oxygen equivalent of energy supplied bythe anaerobic  glycogenolytic system.

Oxygen supplied by the body oxygen stores (Hemoglobin, myoglobin and extra oxygen extracted from the blood in capillaries and interstitial fluid


   Energy demand of the exercise is completely met by the aerobic energy transformation or all of the ATP required by the exercise is resynthesized by the aerobic phosphorylation


  EPOC(Excess Post exercise Oxygen Consumption), Recovery Oxygen, “Oxygen debt ?”
  Factors responsible for oxygen deficit
Oxygen equivalent of energy supplied by the hydrolysis of ATP and CP
  Oxygen equivalent of energy supplied by the anaerobic glycogenolysis (HLA is produced)
Extra amount of oxygen extracted from the oxygen stores

Factors responsible for EPOC

 Oxygen required to resynthesize ATP & CP form ADP & Pi
 Oxygen required for the resynthesis of glycogen from lactic acid in liver
 Oxygen required to replenish the O2 stores of the body
 Extra O2 consumed by the heart which has higher than resting-level activity for long time following the termination of exercise
 Extra O2 consumed by the respiratory muscles which have higher than resting-level activity for long time following the termination of exercise
 Extra O2 consumed by the body following the termination of exercise due to higherthan resting body temperature(Q10effect)
 Extra O2 consumed due to the hormonal (e.g. Thyroxin, Epinephrine, Cortisol) stimulation of the general metabolism over and above the resting levels (makes the membrane leaky to Na+ - increased activity of Na/K pump)

Oxygen “debt” is larger than oxygen deficit due to the last 4 factors

Why O2 consumption does not increase immediately to the levels required by Steady State exercise?

   Time required to increase the concentration of positive modulators responsible for enhancing the activity of key rate-limiting enzymes – ADP, Pi, Cyclic AMP, Citrate, etc
    Time required to increase the concentration of Krebs Cycle intermediaries – depending on the duration and intensity of exercise the concentration of intermediaries is increased 5 – 15 fold
    Time required to increase body temperature -Q10 effect
     Aerobic energy transformation system has “highInertia” - it is sluggish



Maximal Exercise
Maximum capacity of the organism is to supply and utilize Oxygen.
Protocols for testing VO2 max (Maximal Oxygen Conception)
Single stage superamaximal loads. Multiple stage- progressively exercise testing-Graded Exercise Testing(GXT)  Modes- Cycle erometer, Arm crank ergometer, treadmill, Stair climb ergometer, Swimimng Flume and Rowing ergometer.

  Work load or Vo2 after which there is a progressive, systematic increase in blood lactate concentration
The onset of blood lactic acid accumulation during exercise does not exclusively represent the point in time where the anaerobic metabolism is switched on due to the lack of O2 in the exercising muscle since:
Lactate is produced at all levels of exercise, even during rest, however it is removed as fast as produced –  it has been shown that lactate turn over rate is increased several fold during exercise and is several times faster in trained than untrained individuals

(production = removal)

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