# Exercise Phys. Lecture 3

version from 2018-01-04 15:02

## Section 1

Who has the highest aerobic capacity?those with the most muscle mass, higher cardiac output, higher heart rate
Why use V02 max as a measure for aerobic capacity ('aerobic fitness')Because there are so many systems in the oxygen transport change, using VO2 max includes all of these, as they all link together, VO2 max captures all systems
What is the oxygen transport system -> Pulmonary ventilation -> Hb concentration -> Blood volume and cadiac output-> Peripheral blood flow -> Aerobic metabolism -> back to pulmonary ventilation.
Aerobic contribution VS exercise durationfirst min (0-60)uses ATP-CP system for energy
Aerobic contribution VS exercise durationapprox 60-120 seconds uses glycolysis system for energy
Aerobic contribution VS exercise duration120 seconds +uses oxidative system for energy, slowly increasing from 0 seconds.
What percentage of the energy system does 100m event use90% anaerobic, 10% aerobic
what percentage of the energy system does 400m event use75% anaerobic, 25% aerobic
what percentage of the energy system does 1500m event use25% Anaerobic, 75% aerobic
what percentage of the energy system does 10,000m event use3% anaerobic, 97% aerobic

## Section 2

What does V02 max depend on A good cardio-vascular system and high cardiac output. Well-developed oxidative capacity in skeletal muscle (e.g. mitochondria, oxidative enzymes etc).
What are the peripheral limitations on VO2 max Isolated muscle can use more oxygen than the heart can deliver. (e.g., one vs two legged exercise: O2 extraction by quadriceps during one-legged exercise is 2-3 times higher than that measured in the same muscle group during whole body exercise)
Longditudial aerobic training studies looking at VO2 max show: – 2.2 fold increase in mitochondrial enzymes, but only ~20-40% increase in Vሶ O2max – Individuals with a similar Vሶ O2max exhibit two-fold range of mitochondrial enzymes. Cardiac output = limiting factor.
What did the training study by Montero 2015 show Reducing blood volume through phlebotomy after training (to pre-training levels) reduces both cardiac output and VO2max to pre-training levels. Therefore Oxygen delivery and thus V02 max is primarily limited by stroke volume.
Explain stray-gundersens 'A dogs story' storyRemoval of the pericadium (lining of heart) increased SV, which increase cardiac output and increase in V02 max.
VO2 max- graph of what effects it Pg 3, slide 13 lecture 3
What is a 'good' VO2 max; absolute and relative score?Depends on individual. Divide VO2 max L/min by weight Kg, to get relative VO2 max.
When assessing fitness using relative VO2 max , why do men have higher values than females?As men have higher amount of lean muscle mass, more active muscle mass. Fat mass barely takes place in metabolism so we change it to make comparison fair.
When to perform surgery or not?– VO2max < 10 mL/kg/min or < 40% predicted: NO! – VO2max > 20 ml/kg/min or > 75% predicted: YES!