Question

Predict what will happen to the following lung volumes and capacities during strenuous exercise. Assume that you are comparing from a baseline of normal resting respiration.

WITH EXPLANATION PLEASE

Lung Volume or Capacity	Predicted change from resting baseline : Use Increase, Decrease or No Change
TLC (total lung capacity)	No change
VC (Vital capacity)
IC (Inspiratory capacity)
FRC (Functional residual capacity
TV (Tidal volume)
IRV (Inspiratory reserve volume)
ERV (Expiratory reserve volume)
RV   (Residual volume)

Answer 1

Sr.No	Lung Volume or Capacity	Predicted change from resting baseline: Use Increase, Decrease or No Change
1.	TLC (total lung capacity)	No change
2.	VC (Vital capacity)	Increases
3.	IC (Inspiratory capacity)	Increases
4.	FRC (Functional residual capacity)	No change
5.	TV (Tidal volume)	Increases
6.	IRV (Inspiratory reserve volume)	Decreases
7.	ERV (Expiratory reserve volume)	Decreases
8.	RV   (Residual volume)	No Change

Following is the explanation:

> TLC (total lung capacity) and VC (Vital capacity)

In general regular exercise does not substantially change measures of pulmonary function such as total lung capacity, the volume of air in the lungs after taking the largest breath possible (TLC), and forced vital capacity, the amount of air able to be blown out after taking the largest breath possible.

> RC (Functional residual capacity)

The results showed an FRC decrease during exercise. The mechanism of this decrease was considered due to a specific respiratory pattern during exercise. The minute ventilation increased during exercise with the increase of both respiratory frequency and tidal volume.

> IRV (Inspiratory reserve volume) and TV (Tidal volume)

The IRV acts as a reservoir of extra lung volume that can become inflated with air as we need it, such as when there is a demand for more oxygen inhalation and CO2 exhalation during exercise. Therefore with exercise, there is a decrease in IRV as tidal volume increases and takes over this “space” in the lung.

> ERV (Expiratory reserve volume)

The ERV decreases during exercise since there is a need to expire more air from the lungs that we typically do at rest. This is because we need a larger volume of the lung to be involved in gas exchange with new air coming in with each breath.

> RV (Residual volume)

There is a limit however as to how much we can breathe out. There is a small amount of air that needs to remain in the lungs to keep them inflated, called the residual lung volume. Residual volume does not change very much (if any) during exercise even with increasing tidal volume.