energy transfer in exercise. immediate energy zatp-cp stored in muscle zsprints zheavy weightlifting...
TRANSCRIPT
Energy Transfer in Exercise
Immediate Energy
ATP-CP stored in musclesprints heavy weightliftingevents < 10-15 seconds
Short-Term Energy
Lactic AcidAnaerobic Glycolysis LAIntermediate energy sourceMaximal intensity for 60-180
seconds400 meter run100 meter swim
Blood Lactate Concentration
25 50 75 100
Blo
od L
acta
te C
once
ntra
tion
Percent VO2 max
Untrained Threshold
Trained Threshold
TrainedUntrained
Factors Related to Lactate Threshold
Low tissue O2 (hypoxia)
Dependence on glycolysis
Activation of FT muscle fibers
Reduced ability to remove lactate
Training the Lactate Threshold
Training can threshold by 20-30%
genetics training effect of producing less LAtraining effect of more efficient LA
removal
Long-Term EnergyO
xyge
n U
ptak
e (m
l / k
g-m
in)
0 2 4 6
Exercise Time (min.)8
5
10
15
20
Trained
Untrained
Steady State/Rate
Initiation of Exercise
O2 uptake rises exponentially
Plateau is reached between 3-4 minutes
Oxygen Deficit
Quantity of O2 that would have been consumed had steady state been reach immediately
Oxygen Deficit
Endurance training reach steady-state sooner total O2 consumption is anaerobic component
VO2max
With progressively demanding aerobic exercise, region where O2 uptake plateaus
Represents an individual’s capacity for aerobic resynthesis of ATP
Helps determine one’s ability to sustain high intensity exercise for longer than 4-5 minutes
Energy Spectrum
Duration of Maximal Exercise
Seconds Minutes
10 30 60 2 4 10 31 60 120
%Anaerobic 90 80 70 50 35 15 5 2 1
%Aerobic 10 20 30 50 65 85 95 98 99
Energy Spectrum
Maximal Exercise Time (minutes)
Per
cent
of
Tot
al E
nerg
y Y
ield
50
100
603010
O2 Dept
Exercise Time
O2 C
onsu
mpt
ion
O2 deficit O2 requirement
Resting O2 consumption
Start Exercise End Exercise
Steady-state O2 consumption
End Recovery
O2 Dept
Classic O2 Dept (EPOC) Theory
Fast component – represents O2 required to rebuild ATP and CP
Slow component – removal of tissue lactate via conversion to glycogen or oxidation to CO2 and H2O
Contemporary EPOC Theory
Short duration, light to moderate exercise
Recovery O2 serves to replenish high-energy phosphates (several minutes
Contemporary EPOC Theory
Longer duration, high intensity aerobic exercise
Much longer period of O2 uptake
Some used for lactate glycogen
Causes of EPOC following Heavy Exercise
Resynthesize ATP and CPResynthesize lactate to glycogenOxidate lactate in energy metabolismRestore O2 to bloodThermogenic effects of elevated core temp.Thermogenic effects of hormonesEffects of HR, ventilation, & other
functions.
Recovery
Steady state aerobic exercise or 5 to 10 second bouts of maximal exercise not lactate accumulation recovery is rapid
Fast component
Recovery
Longer periods of anaerobic exercise
Lactate accumulation
Fast and slow components
Recovery
Exercise at 50% of VO2max can be continued at steady-state w/o build up
At 60-75% of VO2max – no steady-state lactate accumulates
Lactate removal is accelerated by aerobic exercise