Transcript ppt Oxygen Debt-Energy Systems - NCEA-Physical

Energy Transfer During
Exercise
The Energy Systems
Energy Sources
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From Food:
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CHO = 4 kcal
Fat = 9 kcal
Pro = 4 kcal
For Exercise:
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ATP > ADP + P
Methods of Supplying ATP For
Energy
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Stored ATP
CP or ATP-CP
Anaerobic metabolism/glycolysis/lactic
acid system
Aerobic metabolism
ATP-PC System
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Intramuscular phosphagens
Short anaerobic
Uses stored ATP
Strength/power movements
Replenishes
Lactic Acid System
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Glycolytic
Long anaerobic
Burns glucose
Accumulates lactate at high intensities
Muscular endurance activities
Blood Lactate Threshold
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Exercise intensity at the
point of lactate buildup.
Predicts aerobic
exercise performance.
Untrained ~ 55% of
VO2 max.
Trained ~ 75% of VO2
max.
Aerobic System
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Oxidative
Burns fatty acids
Long-term energy
Better butter burner
Cardiorespiratory endurance activities
Energy Systems
ATP-PC
Glycolysis
Stored ATP
Breakdown of
allows for 3-5 glucose – end
sec. of activity result is
pyruvate
ATP-PC used
Converted to
up in 10-15
lactic acid if
sec. of activity anaerobic
envir.
Beta Oxidation
Breakdown of
triglyceride –
yields ATP
> Fat oxidation
= better butter
burner
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120
100
80
60
40
20
Work Time
5
13
14
45
3:
45
0
10
% of energy from aerobic
The Energy-Time Continuum
As the work time
increases, the
percentage of
energy contributed
by the aerobic
system increases.
Oxygen Uptake During Aerobic
Exercise
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Increases sharply at
onset
Levels off within a
few minutes if pace
is constant (steady
state)
Oxygen demand met
by supply
Maximal Oxygen Uptake
(VO2 max)
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The region where
oxygen uptake
plateaus and does
not increase despite
an additional
increase in exercise
intensity.
Maximal Oxygen Uptake
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Affected by body size: larger size means
larger VO2 max.
Absolute oxygen uptake (ml.min.)
Relative oxygen uptake (ml.kg.min.)
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Relative to body mass
Oxygen Deficit
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Difference between
oxygen consumed
during exercise and
amount that would
have been
consumed had a
steady rate, aerobic
metabolism occurred
at onset of exercise.
Oxygen Deficit:
Trained vs. Untrained
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Trained reach steady rate quicker
Higher total oxygen consumption
Less reliance on anaerobic glycolysis
Lower deficit in trained individuals due
to:
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Earlier aerobic ATP production
Less lactate formation
Excess Post-Exercise Oxygen
Consumption (EPOC)
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Formerly called oxygen debt
Excess oxygen above the resting level
in recovery
Most lactate does not synthesize into
glycogen as originally thought
Heart, liver, kidneys, and skeletal
muscle use lactate as energy substrate
during recovery
Active Recovery for Heavy
Exercise
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Facilitates lactate removal because of:
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increased perfusion of blood through the
liver and heart
increased blood flow in muscles because
muscle tissue oxidizes lactate during Krebs
Cycle