8392 Lecture Notes - Lecture 6: Vo2 Max, Endurance Training, Cardiac Output
20 Jun 2018
School
Department
Course
Professor
LECTURE 6
Assessing Training and adaptations for endurance activity part 2
- Mathematical calculation of VO2 max
oCalc of vo2 max
Product of maximal cardiac output and arteriovenous difference
oDifferences in VO2 max in different populations
Primarily due to differences in SV max
oImprovements in VO2 max
Approx. 50% inc SV and approx. 50% inc in a-vo2 (diff btw oxygen in
capillaries and in muscle cell)
Shorter duration training (4months)
Inc SV > inc a-vo2
Longer duration training (28months)
Inc in a-vo2 max > SV
oWhat effects a-vo2
More mitochondria
More blood cells
Vascularization
Kreb cycle intermediates
- Factors causing inc in VO2 max
find more resources at oneclass.com
find more resources at oneclass.com
o
- Stroke volume
oInc max SV
Inc preload EDV
Inc plasma volume
Inc venous return; compression garments
Inc ventricular volume; frank starling mechanism
Dec afterload
Dec arterial constriction
Inc maximal muscle blood flow with no change in arterial pressure
Inc contractility
oChanges occur rapidly
11% inc in plasma volume, 7% inc VO2 max, and 10% inc in stroke volume
- Arteriovenous O2 difference
oInc muscle blood flow
Dec SNS vasoconstriction
oImproved ability of the muscle to extract o2 from the blood
Inc capillary density slows blood flow through muscle
find more resources at oneclass.com
find more resources at oneclass.com
Inc mitochondrial number
- Endurance training induced changes in fiber type and capillarity
oFast to slow shift in muscle fibre type
Reduction in fast myosin
Inc in slow myosin
Extent of change determined by duration of training and genetics
oIncreased number of capillaries
Enhanced diffusion of oxygen
Increased removal of wastes
- Endurance training increases mitochondrial content in skeletal muscle fibres
oMitochondria in muscle
Subsarcolemmal are located below sarcolemma
Intermyofibrillar are located around contractile proteins
oMitochondrial content increases quickly
Depends on intensity and duration of training
Can increase 50-100% within first 6 weeks
oResults in increased endurance performance
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Assessing training and adaptations for endurance activity part 2. Mathematical calculation of vo2 max: calc of vo2 max. Product of maximal cardiac output and arteriovenous difference: differences in vo2 max in different populations. Primarily due to differences in sv max: improvements in vo2 max. 50% inc in a-vo2 (diff btw oxygen in capillaries and in muscle cell) Inc in a-vo2 max > sv: what effects a-vo2. Inc maximal muscle blood flow with no change in arterial pressure. 11% inc in plasma volume, 7% inc vo2 max, and 10% inc in stroke volume. Arteriovenous o2 difference: inc muscle blood flow. Dec sns vasoconstriction: improved ability of the muscle to extract o2 from the blood. Inc capillary density slows blood flow through muscle. Endurance training induced changes in fiber type and capillarity: fast to slow shift in muscle fibre type. Extent of change determined by duration of training and genetics: increased number of capillaries.
