Wk 5 pt1 - Cardiopulmonary responses to submaximal, incremental and maximal aerobic exercise

What is cardiopulmonary responses?

These are mechanisms in the body that occur to meet the body’s requirements when we exercise. (e.g., ATP requirements, and Production of lactate and CO₂.

What is VO₂?

It is a description of O₂ utilisation by the body. It increases in proportion to exercise intensity.

How is VO₂ measured?

In either absolute terms (litres per minute) or relative to body mass (ml/kg/min)

What is the body’s VO₂ at rest?

It is around 0.2-0.3L/min (or 3.5-5.0 ml/kg/min)

What are some changes associated with VO₂?

Some things include ventilation, cardiac output (L/min), heart rate, redistribution of blood flow to exercising muscle, and extraction of oxygen from the blood into the muscle and mitochondria.

What is the Fick equation?

VO₂ represents oxygen consumption (mL/min)

Q represents cardiac output (L/min)

a - v_o2 diff represents the arteriovenous oxygen difference (mL/dL)

What is VO₂ max?

The description of the maximal rate at which O₂ can be utilised.

What is VO₂ max limited by?

The rate of delivery and the rate of consumption within the muscle.

What is VO₂ max associated with?

The capacity to do long periods of exercise and the intensity of maintaining this form of exercise. It is a determining factor in endurance performance.

What are some key factors in VO₂ max?

Maximal oxygen delivery (Q max, HR max, SV max), O₂ carrying capacity of the blood (Hb, HCt), capillarisation of muscle, a - v_o2 diff, and maximum capacity of the muscle to utilise oxygen.

VO₂ responses during exercise

At the 4 minute mark, the individual has achieved VO₂ corresponding to moderate intensities of exercise. As exercise intensities increase beyond moderate levels, VO₂ will increase gradually, indicating a higher metabolic demand on the body.

What are some other responses you can use to estimate O₂ consumption and VO₂ max?

Exercise intensity (e.g., running speed, or cycling watts), heart rate, and perceived exertion.

A general guide to responses to increasing work-rate. (VO₂ max)

These numbers were on a person weighing 90 kg.

A general guide to responses to increasing work-rate. (Heart rate)

A general guide to responses to increasing work-rate. (Ventilation)

A general guide to responses to increasing work-rate. (O₂ and CO₂ consumption)

Although % remains consistent, ventilation is increasing in response to increased CO₂ production to ensure levels remain in permissible range.

A general guide to responses to increasing work-rate. (Respiratory Exchange Ratio)