Did you know?
At rest, an adult will have a tidal volume of 500 ml per breathing cycle.
During exercise, the respiratory system adapts by increasing tidal volume. This tidal volume encroaches on the IRV and ERV, and when the tidal volume can no longer increase, the respiratory rate accelerates.
A better understanding of the process
- Even when you blow as hard as you can, there is still air in your lungs - this volume is called residual volume (RV).
- With calm breathing, an adult has an inspiratory tidal volume (VT) of around 0.5 l.
- Total lung capacity - known as TLC, corresponds to residual volume + vital capacity (VC). This represents the maximum amount of air a person is able to inhale and/or exhale during forced breathing. These volumes can be calculated with a spirometer.
- Inspiratory capacity - or IC - is the maximum amount of air inspired after a normal exhalation. This volume is about 3.6 liters for an adult.
- Functional Residual Capacity (FRC) is the amount of air remaining in the lungs after normal exhalation. For an adult, this volume is around 2.4 liters.
- Vital capacity - or VC - is the maximum amount of air exhaled after maximum inspiration. This volume is about 4.8 liters for an adult.
Read article for a deeper understanding of lung volumes.
What is important to remember
During exercise, the volume of air circulated by the lungs, which is 6 to 8 liters per minute at rest, increases to 80 to 150 liters per minute, depending on the intensity of the exercise. For top athletes, this volume can even reach 250 liters per minute. Thus, a greater quantity of O2 enters the lungs where the blood is recharged, allowing a better supply of oxygen to the body.
This article is part of a series of articles about breathing and breathlessness. Visit here for other articles.