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

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• 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 EPOCOxygen 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 Physiological Adaptations Due to Endurance TrainingEndurance 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