The integration of cardiovascular
and respiratory function
Oxygen Consumption (VO2)
• The amount of o2 taken up and
consumed by the body for metabolic
processes.
• Equal to amount of inspired air minus
amount of expired air
• VO2 is proportional to workload
• Measured by a metabolic cart in a lab
environment
..cont.
• The maximal rate of oxygen
consumption would occur at max HR,
SV and a-vo2 diff.
• VO2 max is the maximal amount of O2
that can be taken in and used for the
metabolic production of ATP during
exercise
Limiting factors to VO2
• The respiratory system:inadequate
ventilation and oxygen diffusion limitations
• The cardiovascular system: inadequate
blood flow; inadequate oxygen-carrying
capacity (Q likely the biggest limiting factor)
• Energy systems: lack of mitochondria
Lactate Threshold
• As workload
increases, the body
relies more on the
anaerobic system,
resulting in
accumulated blood
lactate.
Oxygen Deficit and EPOC
• Oxygen deficit: the difference between
the O2 required to perform a task and
the O2 consumed before reaching
steady state (sub-maximal)
• Trained individuals reach this state
earlier than non-trained individuals.
EPOC
• Excess post-exercise oxygen
consumption:The extra oxygen required to
replenish oxygen to the various systems that
were taxed during the exercise.
• Eg: refilling phosphocreatine reserves,
replenishing O2 in blood and tissues,
lowering breathing rate, lowering body temp.
and increasing blood lactate removal.
• Active recovery can aid in the removal of
blood lactate.
Physiological Adaptations Due to
Endurance Training
Oxygen consumption
• The amount of O2 taken up and
consumed by the body for metabolic
process is called oxygen consumption
(VO2)
Oxygen dissociation curve